Content uploaded by Nicolas Corradi
Author content
All content in this area was uploaded by Nicolas Corradi on Oct 13, 2016
Content may be subject to copyright.
A phylum-level phylogenetic classification of
zygomycete fungi based on genome-scale data
Joseph W. Spatafora
1
Ying Chang
Department of Botany and Plant Pathology, Oregon State
University, Corvallis, Oregon 97331
Gerald L. Benny
Katy Lazarus
Matthew E. Smith
Department of Plant Pathology, University of Florida,
Gainesville, Florida 32611
Mary L. Berbee
Department of Botany, University of British Columbia,
Vancouver, British Columbia, V6T 1Z4 Canada
Gregory Bonito
Department of Plant, Soil, and Microbial Sciences, Michigan
State University, East Lansing, Michigan 48824
Nicolas Corradi
Department of Biology, University of Ottawa, Ottawa,
Ontario, K1N 6N5 Canada
Igor Grigoriev
US Department of Energy (DOE) Joint Genome Institute,
2800 Mitchell Drive, Walnut Creek, California 94598
Andrii Gryganskyi
L.F. Lambert Spawn Co., Coatesville, Pennsylvania 19320
Timothy Y. James
Department of Ecology and Evolutionary Biology, University
of Michigan, Ann Arbor, Michigan 48103
Kerry O’Donnell
Mycotoxin Prevention and Applied Microbiology Research
Unit, NCAUR-ARS-USDA, 1815 N. University Street, Peoria,
Illinois 61604
Robert W. Roberson
School of Life Sciences, Arizona State University, Tempe,
Arizona 85287
Thomas N. Taylor
2
Department of Ecology and Evolutionary Biology, and
Natural History Museum and Biodiversity Research Center,
University of Kansas, Lawrence, Kansas 66045
Jessie Uehling
Rytas Vilgalys
Biology Department, Box 90338, Duke University, Durham,
North Carolina 27708
Merlin M. White
Department of Biological Sciences, Boise State University,
Boise, Idaho 83725
Jason E. Stajich
Department of Plant Pathology & Microbiology and Institute
for Integrative Genome Biology, University of California–
Riverside, Riverside, California 92521
Abstract: Zygomycete fungi were classified as a single
phylum, Zygomycota, based on sexual reproduction by
zygospores, frequent asexual reproduction by sporangia,
absence of multicellular sporocarps, and production of
coenocytic hyphae, all with some exceptions. Molecular
phylogenies based on one or a few genes did not support
the monophylyof the phylum, however, and the phylum
was subsequently abandoned. Here we present phyloge-
netic analyses of a genome-scale data set for 46 taxa,
including 25 zygomycetes and 192 proteins, and we dem-
onstrate that zygomycetes comprise two major clades
that form a paraphyletic grade. A formal phylogenetic
classification is proposed herein and includes two phyla,
six subphyla, four classes and 16 orders. On the basis
of these results, the phyla Mucoromycota and Zoopago-
mycota are circumscribed. Zoopagomycota comprises
Entomophtoromycotina, Kickxellomycotina and Zoopa-
gomycotina; it constitutes the earliest diverging lineage
of zygomycetes and contains species that are primarily
parasites and pathogens of small animals (e.g. amoeba,
insects, etc.) and other fungi, i.e. mycoparasites. Mucor-
omycota comprises Glomeromycotina, Mortierellomy-
cotina, and Mucoromycotina and is sister to Dikarya.
It is the more derived clade of zygomycetes and mainly
consists of mycorrhizal fungi, root endophytes, and
decomposers of plant material. Evolution of trophic
modes, morphology, and analysis of genome-scale data
are discussed.
Key words: Entomophthoromycotina, fungi, Glo-
meromycotina, Kickellomycotina, Mortierellomyco-
tina, Mucoromycota, Mucoromycotina, paraphyly,
systematics, Zoopagomycota Zoopagomycotina
INTRODUCTION
Despite advances in our understanding of evolutionary
relationships within Kingdom Fungi, the earliest diverg-
ing events are still poorly understood. Included among
these unresolved events are the evolutionary transitions
that ultimately culminated in modern diversity and in
the emergence of terrestrial fungi, including subking-
dom Dikarya, which comprises the phyla Ascomycota
and Basidiomycota. Resolving the earliest branches in
the fungal genealogy is essential to identify characteristics
Submitted 23 Feb 2016; accepted for publication 4 Jul 2016.
1
Corresponding author. E-mail: spatafoj@oregonstate.edu
2
Deceased 28 Apr 2016.
Mycologia, 108(5), 2016, pp. 1028–1046. DOI: 10.3852/16-042
#2016 by The Mycological Society of America, Lawrence, KS 66044-8897
1028
of the ancestral fungi, to determine what traits emerged
with the dawn of terrestrial ecosystems, and to obtain
an accurate assessment of the morphological and genetic
homologies associated with fungal lifestyles. Central to
this transition are the fungi that were once classified
in the phylum Zygomycota Moreau (1954). However,
because the monophyly of Zygomycota was not sup-
ported in recent phylogenetic analyses (e.g. James et al.
2006, Liu et al. 2009, Chang et al. 2015), these fungi are
informally referred to herein as zygomycetes.
Zygomycetes are filamentous, nonflagellated fungi
that mark the major transition away from the earliest
diverging zoosporic fungi in Cryptomycota, Chytridio-
mycota, and Blastocladiomycota toward the rise of
the nonflagellated, filamentous, multicellular Dikarya.
The zygomycetes include: (i) Phycomyces blakesleeanus
and other important model organisms; (ii) species
such as Rhizopus stolonifer that cause economically
significant pre- and postharvest diseases of fruits; (iii)
members of Glomeromycota that colonize roots and
form endomycorrhizal symbioses with more than 80%
of land plants; and (iv) diverse and important patho-
gens or commensals of insects, nematodes, and other
soil invertebrates (Benny et al. 2014, Redecker and
Schüßler 2014). Some zygomycetes significantly benefit
humans by the production of compounds such as lyco-
pene, fatty acids, and biodiesel, but they can also cause
rare and deadly human diseases such as zygomycosis
(Papanikolaou and Panayotou 2007, Wang et al. 2011,
Doggett and Wong 2014).
Abandonment of the phylum Zygomycota was
formalized in Hibbett et al. (2007), which treated
zygomycete fungi as four subphyla incertae sedis, includ-
ing Entomophthoromycotina, Kickellomycotina, Mucor-
omycotina, and Zoopagomycotina and the phylum
Glomeromycota. Mortierella was classified with the mor-
phologically similar Mucorales until multigene analyses
demonstrated that it was phylogenetically distinct from
Mucoromycotina, resulting in the description of the sub-
phylum Mortierollomycotina (Hoffmann et al. 2011).
Results from rDNA and multigene molecular phyloge-
netic studies resolved these zygomycete taxa into two
larger groups. One of the groups, informally known as
“zygomycetes I”, includes Mucoromycotina and Mortier-
ellomycotina and in some studies, Glomeromycota
(James et al. 2006, White et al. 2006, Chang et al.
2015). Mucoromycotina includes Mucor,Rhizopus,and
the majority of the most common and best known zygo-
mycetes. Many of these are fast growing, early colonizers
of carbon-rich substrates, with several species used in
industry for organic acid production and fermen‐
tation (Jennessen et al. 2008). Mortierellomycotina are
common soil fungi that occur as root endophytes of
woody plants and also are commonly isolated as saprobes
(Summerbell 2005). Glomeromycota includes the
arbuscular mycorrhizal fungi, which arguably comprise
the most successful plant-fungal symbiosis on Earth.
Glomeromycota has been a phylogenetic enigma because
itlacksanyknownformofsexualreproduction.Morpho-
logical hypotheses placed Glomeromycota among the
zygomycetes (Gerdemann and Trappe 1974, Morton
and Benny 1990), whereas rDNA-based phylogenies
placed this phylum as sister to Dikarya (Schüßler et al.
2001). Mitochondrial phylogenies (Nadimi et al. 2012,
Pelin et al. 2012) placed Glomeromycota as sister to Mor-
tierellomycotina, which is supported by some but not all
genome-scale phylogenies (Tisserant et al. 2013, Chang
et al. 2015).
The second of the larger groups, “zygomycetes II”,
includes Entomophthoromycota, Kickxellomycotina,
and Zoopagomycotina (James et al. 2006, White et al.
2006, Sekimoto et al. 2011, Ebersberger et al. 2012,
Chang et al. 2015). Zygomycetes II is more difficult of
the two groups to study. In phylogenetic analyses, it
has been weakly supported (James et al. 2006, Sekimoto
et al. 2011) or strongly supported but based only on a
couple of taxa (Chang et al. 2015). Entomophthoromy-
cotina, the “insect destroyers”, includes parasites of
insects and mites, commensals of reptiles and amphib‐
ians, and poorly known parasites of desmid algae.
Kickxellomycotina comprises a diverse assemblage
of fungi associated with the hindgut of arthropods,
saprobic species with broad substrate ranges and myco-
parasites. Zoopagomycotina are either obligate myco-
parasites or pathogens of invertebrates, including
nematodes, rotifers, and amoebae. Members of the
zygomycetes II group are almost exclusively charac‐
terized by associations with animals and fungi with
essentially no associations with living plants, either as
pathogens or symbionts (Benny et al. 2014).
Although the applications of multigene analysis
has resulted in limited phylogenetic resolution of
zygomycetes in kingdom-level analyses, they have led
to significant refinement of evolutionary hypotheses
for selected groups of zygomycetes, based on a combi-
nation of molecular and morphological data. These
include a family-level phylogenetic classification of
Mucorales (Hoffmann et al. 2013), testing of ordinal-
level phylogenetic and taxonomic hypotheses for
Kickxellomycotina (Tretter et al. 2014) and characteri-
zation of the major clades of Entomophthoromycota
and temporal estimates of their origin in the geologic
record (Gryganskyi et al. 2012). However, unlike
Dikarya for which genome data and phylogenomic
analyses have transformed our understanding of phylo-
genetic relationships and evolutionary processes (e.g.
Floudas et al. 2012, Nagy et al. 2014, Kohler et al.
2015), genome data for zygomycetes have been sparse
with respect to phylogenetic depth and breadth
(Gryganskyi and Muszewska 2014). These gaps in
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1029
our knowledge of zygomycete evolution have mani-
fested in a poor understanding of the homology of
numerous life history traits essential to Fungi. These
include characters associated with genomic, metabolic,
reproductive, morphological, biochemical, and ecologi-
cal traits. We attribute the limited amount of environmen-
tal data on zygomycetes to their molecular divergence,
limited amplicon-based barcoding success, and paucity
of well-annotated zygomycete reference data. For
example, Zoopagomycotina comprises 19 genera and
228 described species worldwide, but this subphylum
is only represented in GenBank by 125 DNA sequences
for 17 species, 12 unnamed isolates, and seven environ-
mental samples (NCBI nucleotide database accessed
21 Jan 2016).
Understanding zygomycete relationships from sub-
phyla to species will provide long-awaited insight into
transitions in form and function that changed as fungi
colonized land, became multicellular, evolved true fila-
mentous growth, and established intimate associations
with other clades of life. A robust phylogenetic classifica-
tion of zygomycetes will improve communication among
biologists, ending the current use of confusing alterna-
tive names for poorly defined taxa. Here we leverage
a phylogenomic approach with kingdom-wide sampling
of species and genome-scale sampling of loci to resolve
phylum-level relationships and propose a phylogenetic
classification of the zygomycetes.
MATERIALS AND METHODS
Taxon and genome sampling.
—
Assembled and annotated
genomes of 46 fungi were obtained from GenBank and
Joint Genome Institute as part of the 1000 Fungal Genomes
Project (http://1000.fungalgenomes.org) and published data-
sets (TABLE I). Genomes from 25 of the fungi represented all
zygomycete phyla and subphyla including Mucoromycotina
(12), Mortierellomycotina (2), Glomeromycota (1), Ento-
mophthoromycotina (5), Kickellomycotina (4), and Zoopago-
mycotina (1). The Entomophthoromycotina fungus Pandora
formica was included, but the accession is an assembled RNASeq
of P. formica-infected ant and thus represents a metagenomic
sample and the Zoopagomycotina fungus Piptocephalis cylindros-
pora was sequenced using a single-cell sequencing approach.
Additional early diverging fungi included species from Chytri-
diomycota (6), Blastocladiomycota (2), and Cryptomycota
(1). Five Ascomycota and four Basidiomycota genomes repre-
sented all major subphyla of the subkingdom Dikarya. Three
outgroup species were included from the Metazoa, Choanozoa,
and Ichthyosporea.
Phylogenetic analyses.
—
Phylogenetically informative proteins
(markers) from the James et al. (2013) study of the placement
of Cryptomycota and early branching fungi were used to ana-
lyze relationships. These conserved proteins were identified
by comparing a pan-Eukaryotic set of species from plants,
Metazoa, and Fungi. In total, 192 clusters of orthologous pro-
teins (COPs) were aligned across the 39 eukaryotic species
sampled in James et al. (2013) and built into Profile
Hidden Markov Models (HMM) with TCOFFEE (Notredame
et al. 2000) and HMMER3 (Eddy 2011). Each HMM was then
searched against the predicted proteome from the 46 sam-
pled species in this study with HMMSEARCH. For each marker,
the highest scoring protein sequence in each species was
selected by applying a significance cutoff of 1e-10 and binned
to compose a file of fungal COPs for that marker. Alignments
of sequences orthologous to their marker HMM were gener-
ated with HMMALIGN. The alignments were trimmed with
TRIMAL(Capella-Gutiérrez et al. 2009) using the -strictplus
parameter. The alignments were concatenated into a single
super matrix alignment and analyzed using RAXML (Stamata-
kis 2006) with the ‘-f a’fast bootstrapped tree method
and 100 bootstrap replicates (FIG. 1). The PROTGAMMAAUTO
option was used to determine the best model of amino acid
substitution across the following models with and without
empirical base frequencies: DAYHOFF, DCMUT, JTT, MTREV, WAG,
RTREV, CPREV, BT, BLOSUM62, MTMAM, LG, MTART, MTZOA, PMB,
HIVB, HIVW, JTTDCMUT, FLU, DUMMY, and DUMMY2. As an alterna-
tive test of the organismal tree inferred from the concatenat-
ed analysis and as a measure of potential conflict among
individual sequences, a protein sequence phylogeny for
each COP was inferred with RAxML using the same aforemen-
tioned parameters. The maximum likelihood tree and 100
bootstrapped trees generated by RAxML for each of the 192
individual COPs were analyzed in ASTRAL (Mirarab et al.
2014) to construct a greedy consensus tree under default set-
tings (FIG. 2). Branch support was calculated as the percent-
age of bootstrap replicates that contain a particular branch.
The concatenated alignment and the RAxML and ASTRAL
tree files are available at TreeBASE (accession No. TB2:
S18957). The individual alignments, tree files, and associated
scripts are available at http://zygolife.org/home/data/.
RESULTS
The final concatenated alignment comprised 60 382
amino acid positions after trimming. Individual protein
alignments ranged from 57 to 1048 positions resulting
in an average alignment length of 312 positions. LG
with fixed base frequencies was chosen as the best
model of amino acid substitution. The inferred phylog-
eny from the concatenated alignment supported two
clades of zygomycetes (FIG. 1). The earliest diverging
lineage, which we recognize below as Zoopagomycota,
comprised Entomophthoromycotina, Kickxellomyco-
tina, and Zoopagomycotina and was recovered with
100% BP support. Despite the potential for conflict
due to the mixed nature of the Pandora formica metage-
nomic sample and the single cell genome data from
Piptocephalis, strong support was recovered for their
phylum-level phylogenetic placement (FIG. 1). Ento-
mophthoromycotina and Kickxellomycotina were
supported by 89% BP and 100% BP, respectively. The
clade of zygomycetes including Mucoromycotina, Mor-
tierellomycotina, and Glomeromycota, which we recog-
nize below as Mucoromycota, was supported by 100%
1030 MYCOLOGIA
TABLE I. List of taxa and genome data sources
Species GenBank accession No./JGI Web Portal/(reference)
Allomyces macrogynus ATCC 38327 v3 ACDU00000000.1
Arthrobotrys oligospora ATCC 24927 ADOT00000000 (Yang et al. 2011)
Backusella circina FSU 941 http://genome.jgi.doe.gov/Bacci1
Batrachochytrium dendrobatidis JAM81 ADAR00000000.1
Basidiobolus heterosporus B8920 v1 JNEO00000000.1
Basidiobolus meristosporus CBS 931.73 http://genome.jgi.doe.gov/Basme2finSC
Capsaspora owczarzaki ATCC 30864 v2 ACFS00000000.2 (Suga et al. 2013)
Catenaria anguillulae PL171 http://genome.jgi.doe.gov/Catan1
Coemansia reversa NRRL 1564 JZJC00000000 (Chang et al. 2015)
Conidiobolus coronatus NRRL 28638 JXYT00000000 (Chang et al. 2015)
Conidiobolus thromboides FSU 785 http://genome.jgi.doe.gov/Conth1
Coprinopsis cinerea Okayama7_130 AACS00000000.2 (Stajich et al. 2010)
Cryptococcus neoformans JEC21 GCA_000149245.3 (Loftus et al. 2005)
Drosophila melanogaster vr6.04 http://flybase.org (Adams et al. 2000)
Gonapodya prolifera JEL478 LSZK00000000 (Chang et al. 2015)
Hesseltinella vesiculosa NRRL 3301 http://genome.jgi.doe.gov/Hesve2finisherSC
Homoloaphlyctis polyrhiza JEL142 v1 AFSM01000000.1 (Joneson et al. 2011)
Lichtheimia corymbifera FSU 9682 CBTN000000000.1
Lichtheimia hyalospora FSU 10163 http://genome.jgi.doe.gov/Lichy1
Linderina pennispora ATCC 12442 http://genome.jgi.doe.gov/Linpe1
Martensiomyces pterosporus CBS 209.56 http://genome.jgi.doe.gov/Marpt1
Monosiga brevicolis MX1 v1 ABFJ00000000.1 (King et al. 2008)
Mortierella elongata AG-77 http://genome.jgi.doe.gov/Morel2
Mortierella verticillata NRRL 6337 AEVJ00000000.1
Mucor circinelloides CBS277.49 http://genome.jgi.doe.gov/Mucci2
Neurospora crassa OR74A AABX00000000.3 (Galagan et al. 2003)
Orpinomyces sp. C1A ASRE00000000.1 (Youssef et al. 2013)
Pandora formicae v1 GCRV00000000.1
Phycomyces blakesleeanus NRRL 1555 http://genome.jgi.doe.gov/Phybl2 (Corrochano et al. 2016)
Piptocephalis cylindrospora RSA 2659 http://genome.jgi.doe.gov/Pipcy2/Pipcy2.home.html
Piromyces sp. E2 http://genome.jgi.doe.gov/PirE2_1
Puccinia graminis f. sp. tritici CRL 75-36-700-3 AAWC00000000.1 (Duplessis et al. 2011)
Ramicandelaber brevisporus CBS 109374 http://genome.jgi.doe.gov/Rambr1
Rhizophagus irregularis DAOM 181602 JARB00000000.1 (Tisserant et al. 2013)
Rhizopus delemar RA 99-880 AACW00000000.2 (Ma et al. 2009)
Rhizopus microsporus var chinensis CCTCC M201021 CCYT00000000.1 (Wang et al. 2013)
Rhizopus microsporus var microsporus ATCC 52813 http://genome.jgi.doe.gov/Rhimi1_1
Rozella allomycis CSF55 ATJD00000000.1 (James et al. 2013)
Saccharomyces cerevisiae S288C.vR64-2-1 http://yeastgenome.org/(Goffeau et al. 1996)
Saksenaea vasiformis B4078 JNDT00000000.1
Schizosaccharomyces pombe 972h-.vASM294v2 http://www.pombase.org/ (Wood et al. 2002)
Spizellomyces punctatus DAOM BR117 v1 ACOE00000000.1
Umbelopsis ramanniana NRRL 5844 http://genome.jgi.doe.gov/Umbra1
Ustilago maydis 521 v190413 AACP00000000.2 (Kamper et al. 2006)
Yarrowia lipolytica CLIB122 GCA_000002525.1 (Dujon et al. 2004)
Zoophthora radicans ATCC 208865 http://genome.jgi.doe.gov/ZooradStandDraft_FD/
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1031
BP, and it was resolved as sister to Dikarya with 100%
BP. Mucoromycotina and Mortierellomycotina were
both supported by 100% BP, although the latter with
limited taxon sampling. The arbuscular mycorrhizal
species Rhizophagus irregularis was sister to Mucoromy-
cotina and Mortierellomycotina with 97% BP. Umbelop-
sis was placed outside of the core Mucorales clade with
100% BP. Internal nodes pertaining to the placement
of Saksenaea and Hesseltinella within Mucorales were
only moderately supported by the analyses. The phylo-
genetic placement of Blastocladiomycota and Chytri-
diomycota was not strongly supported by these
analyses, and their branching order is essentially inter-
changeable (FIGS. 1, 2).
The ASTRAL analyses provided an additional assess-
ment of organismal phylogeny and identified nodes
that may be affected by ancient incomplete lineage
sorting (FIG. 2). Despite low bootstrap values, the
node placing Blastocladiomycota as sister group to
the nonflagellated fungi was supported by 90%
ASTRAL branch support (ABS). The clades defined
below as Zoopagomycota and Mucoromycota were
supported by 96% and 100% ABS, respectively, and
the monophyly of Mucoromycota plus Dikarya was sup-
ported by 95% ABS. Within Zoopagomycota, lower
levels of ABS characterized the placement of Piptoce-
phalis (60%) and the branch defining Entomophthor-
omycotina (82%). Within Mucoromycotina, low levels
FIG. 1. RAxML phylogenetic tree of Kingdom Fungi based on the concatenated alignment of 192 conserved orthologous proteins.
All branches received 100% bootstrap partitions except where noted by number above or below respective branches. Example images
include: a. Rhizopus sporangium (SEM). b. Phycomyces zygospore (LM). c. Mortierella chlamydospores (SEM). d. Rhizophagus spores and
hyphae (LM). e. Conidiobolus secondary (replicative) conidia forming on primary conidium (SEM). f. Basidiobolus ballistosporic
conidium (SEM). g. Piptocephalis merosporangia (SEM). h. Linderina merosporangium (SEM). LM: light micrograph, SEM: scanning
electron micrograph.
1032 MYCOLOGIA
of ABS characterized the placement of Rhizophagus
(68%) and Hesseltinella and Saksenea within Mucorales.
TAXONOMY
Our classification follows the principles promoted in
Hibbett et al.’s (2007) phylogenetic classification of
Kingdom Fungi. All taxa are either demonstrated or
presumed to be monophyletic and are autotypified by
validly published genera. The name Zygomycota
Moreau is rejected as a name for either clade of zygo-
mycetes. Its taxonomic and nomenclatural use is in ref-
erence to the zygote, i.e. zygospore, formed through
gametangial conjugation in the sexual reproductive
phase. The zygospore, however, is not a synapomorphy
for either clade of zygomycete fungi; rather it is a
sympleisiomorphic trait inherited from the com‐
mon ancestor of Zoopagomycota, Mucoromycota,
and Dikarya (FIG. 1). As such, these findings support
the discontinued use of Zygomycota to avoid confusion
and misrepresentation of a more recent common
ancestor between Zoopagomycota and Mucoromycota
as opposed to Mucoromycota with Dikarya. Descrip-
tions of new taxa follow phylogenetic nomencla‐
ture (Cantino 2010) and define the least inclusive
monophyletic lineage as illustrated in a reference phy-
logenetic tree (FIG. 1). The classification presented
here is restricted to fungi historically classified as zygo-
mycetes, except where they have been demonstrated
not to be members of Kingdom Fungi (e.g. the tradi-
tional ‘trichomycete’orders Eccrinales and Amoebi-
diales; Benny and O’Donnell 2000, Cafaro 2005).
Unnecessary intercalary taxa are avoided, and the clas-
sification does not treat taxa below the level of order.
The proposed classification includes two phyla, six
subphyla, four classes, and 16 orders (TABLE II).
FIG. 2. ASTRAL consensus cladogram of Kingdom Fungi based on analyses of individual bootstrap trees for each of 192
conserved orthologous proteins. All branches received 100% ASTRAL branch support except where noted by number above or
below respective branches.
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1033
Phylum: Mucoromycota Doweld, Prosyllabus Tracheo-
phytorum, Tentamen systematis plantarum vascularium
(Tracheophyta): LXXVII. 2001, emend. Spatafora &
Stajich.
Synonym: Zygomycota F. Moreau, Encyclopédie
Mycologique 23:2035. 1954 (pro parte).
Type: Mucor P. Micheli ex L. (1753).
Emendation: Phylum Mucoromycota is emended
here to apply to all descendants of the node defined
in the reference phylogeny (FIG. 1) as the terminal
Mucoromycota clade. It is the least inclusive clade con-
taining Mucoromycotina, Mortierellomycotina, and
Glomeromycotina. Characters associated with sexual
reproductive states, where known, include zygospore
production by gametangial conjugation. Asexual
reproductive states can involve chlamydospores and
spores produced in sporangia and sporangioles.
Commentary. The name Mucoromycota Doweld
(2001) formally specifies the group referred to as
zygomycetes I in the INTRODUCTION. It is preferred to
Glomeromycota C. Walker & A. Schüßler (2001)
because it is more representative of the taxa that com-
prise the phylum. Mucoromycota shares a most recent
common ancestor with Dikarya and it is characterized
by plant-associated nutritional modes (e.g. plant sym-
bionts, decomposers of plant debris, plant pathogens
etc.) and only rare or derived ecological interactions
with animals (e.g. primarily associated with opportunis-
tic infections). Zygospores tend to be globose, smooth
or ornamented, and produced on opposed or apposed
suspensor cells with or without appendages. Asexual
reproduction typically involves the production of spor-
angiospores in sporangia or sporangioles, or chlamy-
dospores. Hyphae tend to be large diameter and
coenocytic with the exception of the delimitation of
reproductive structures by adventitious septa.
Subphylum: Glomeromycotina (C. Walker & A. Schüßler)
Spatafora & Stajich, subphylum and stat. nov.
MycoBank MB816301
Replaced name: Glomeromycota C. Walker & A.
Schüßler, in Schüßler et al., Mycol. Res. 105:1416. 2001.
Type: Glomus Tul. & C. Tul. 1845.
Description: Subphylum Glomeromycotina is erected
here for the least inclusive clade containing Archaeos-
porales, Diversisporales, Glomerales, and Paraglomerales
(Redecker & Schüßler 2014). Sexual reproduction is
unknown and asexual reproduction is by specialized
spores that resemble azygospores or chlamydospores.
Class: Glomeromycetes Caval.-Sm., Biol. Rev. 73:246.
1998. (as “Glomomycetes”).
Orders: Archaeosporales C. Walker & A. Schüßler, in
Schüßler et al., Mycol. Res. 105:1418. 2001; Diversispor-
ales C. Walker & A. Schüßler, Mycol. Res. 108:981. 2004;
Glomerales J.B. Morton & Benny, Mycotaxon 37:473.
1990. (as “Glomales”); Paraglomerales C. Walker & A.
Schüßler, in Schüßler et al., Mycol. Res. 105:1418. 2001.
Commentary. Glomeromycotina includes all fungi that
form arbuscular mycorrhizae and Geosiphon,asymbiont
of cyanobacteria in the genus Nostoc.Sexualreproduc-
tion is unknown but supported by genome evidence
(Ropars et al. 2016). Asexually formed chlamydospore-
like spores are borne terminally, laterally, or intercalary
on specialized hyphae. Most species produce spores
directly in soil or roots, but several species in different
lineages make macroscopic sporocarps (Gerdemann
and Trappe 1974). Arbuscules, the site of bidirectional
nutrient transfer in arbuscular mycorrhizae, are modi-
fied, highly branched haustorium-like cells that are pro-
duced in cortical plant root cells. Some taxa also
produce darkly staining, intercellular, and intracellular
vesicles. Species of Glomeromycotina produce coenocy‐
tic hyphae that can harbor bacterial endosymbionts
(Bianciotto et al. 2003, Torres-Cortés and Ghignone
2015). These fungi were previously treated as a family
TABLE II. Phylogenetic classification of zygomycete fungi
Mucoromycota Doweld (2001)
Glomeromycotina (C. Walker & A. Schüßler) Spatafora &
Stajich, subphylum and stat. nov.
Glomeromycetes Caval.-Sm. (1998)
Archaeosporales C. Walker & A. Schüßler (2001)
Diversisporales C. Walker & A. Schüßler (2004)
Glomerales J. B. Morton & Benny (1990)
Paraglomerales C. Walker & A. Schüßler (2001)
Mortierellomycotina Kerst. Hoffm., K. Voigt & P.M.
Kirk (2011)
Mortierellales Caval.-Sm. (1998)
Mucoromycotina Benny (2007)
Endogonales Moreau ex R.K. Benj. (1979)
Mucorales Fr. (1832)
Umbelopsidales Spatafora & Stajich, ord. nov.
Zoopagomycota Gryganskyi, M.E. Smith, Stajich & Spatafora,
phylum nov.
Entomophthoromycotina Humber (2007)
Basidiobolomycetes Doweld (2001)
Basidiobolales Jacz. & P.A. Jacz. (1931)
Entomophoromycetes Humber (2012)
Entomophthorales G. Winter (1880)
Neozygitomycetes Humber (2012)
Neozygitales Humber (2012)
Kickxellomycotina Benny (2007)
Asellariales Manier ex Manier & Lichtw. (1978)
Dimargaritales R.K. Benj. (1979)
Harpellales Lichtw. & Manier (1978)
Kickxellales Kreisel ex R.K. Benj. (1979)
Zoopagomycotina Benny (2007)
Zoopagales Bessey ex R.K. Benj. (1979)
1034 MYCOLOGIA
within Endogonales (Glomeraceae, Gerdemann and
Trappe 1974), an order within the class Zygomycetes
(Glomales, Morton and Benny 1990) and as a phylum
more closely related to Dikarya (Glomeromycota, Schüß-
ler et al. 2001). Its membership in Mucoromycota is sup-
ported by genome-scale phylogenetic analyses (FIG.1)
and by gene content analyses (Tisserant et al. 2013).
Subphylum: Mortierellomycotina Kerst. Hoffm.,
K. Voigt & P.M. Kirk, in Hoffmann, Voigt & Kirk,
Mycotaxon 115:360. 2011.
Order: Mortierellales Caval.-Sm., Biol. Rev. 73:
246. 1998.
Commentary. Mortierellomycotina reproduce asexu-
ally by sporangia that either lack or have a highly
reduced columella. Mortierella was historically classified
within Mucorales, but molecular phylogenetic (Hoff-
mann et al. 2011) and phylogenomic analyses (Tisser-
ant et al. 2013) rejected this hypothesis. Rather,
Mortierella is best treated in its own subphylum related
to Mucoromycotina and Glomeromycotina (Hoff-
mann et al. 2011). Molecular phylogenetic analyses
reveal considerable diversity within Mortierellomyco-
tina (Wagner et al. 2013) and environmental sampling
supports a diversity of taxa associated with soils, rhizo-
sphere, and plant roots (Summerbell 2005, Nagy et al.
2011, Shakya et al. 2013). Mortierella species are known
as prolific producers of fatty acids, especially arachido-
nic acid (Higashiyama et al. 2002) and they frequently
harbor bacterial endosymbionts (Sato et al. 2010).
Most species of Mortierellomycotina only form micro-
scopic colonies, but at least two species in the genus
Modicella make multicellular sporocarps (Smith
et al. 2013).
Subphylum: Mucoromycotina Benny, in Hibbett
et al., Mycol. Res. 111:517. 2007.
Orders: Endogonales Moreau ex R.K. Benj., in
Kendrick, ed., Whole Fungus 2:599. 1979. Emend.
Morton & Benny, Mycotaxon 37:473. 1990; Mucorales
Fr., Syst. Mycol. 3:296. 1832; Umbelopsidales Spatafora,
Stajich & Bonito, ord. nov.
Commentary. Mucoromycotina has the largest num-
ber of described species of Mucoromycota and in‐
cludes the well-known model species Mucor mucedo and
Phycomyces blakesleeanus. It also includes industrially
important species of Rhizopus and other genera. Where
known, sexual reproduction within Mucoromycotina
is by prototypical zygospore formation and asexual
reproduction typically involves the copious production
of sporangia and/or sporangioles. Species are fre-
quently isolated from soil, dung, plant debris, and
sugar-rich plant parts (e.g. fruits). As such, fungi in
the Mucoromycotina represent the majority of zygomy-
cetous fungi in pure culture. Endogonales includes both
ectomycorrhizal and saprobicspecies(Bidartondoetal.
2011). Sexual reproduction involves the production of
zygospores by apposed gametangia within a simple, often
sequestrate or enclosed sporocarp that may be hypoge-
ous, embedded in heavily decayed wood, or produced
among foliage of mosses or liverworts. Recent studies sug-
gest that ectomycorrhizae have probably evolved twice
within Endogonales (Tedersoo and Smith 2013). Endo-
gonales represents an independent origin of mycorrhizae
relative to the arbuscular mycorrhizae of Glomeromyco-
tina and ectomycorrhizae of Dikarya (Bidartondo et al.
2011, Tedersoo and Smith 2013, Dickie et al. 2015) and
like many of Mucoromycota, they harbor endohyphal
bacteria (Desiro et al. 2014).
Order: Umbelopsidales Spatafora, Stajich & Bonito,
ord. nov.
MycoBank MB816302
Type: Umbelopsis Amos & H.L. Barnett (1966)
Description: Umbelopsidales is erected here to
apply to all descendants of the node defined in the ref-
erence phylogeny (FIG. 1) as the terminal Umbelopsi-
dales clade. It is the least inclusive clade containing
the genus Umbelopsis. Asexual reproduction is by spo-
rangia and chlamydospores. Sporangiophores may be
branched in a cymose or verticillate fashion. Sporangia
are typically pigmented red or ochre, multi- or single-
spored and with or without conspicuous columella.
Sporangiospores are globose, ellipsoidal, or polyhedral
and pigmented like sporangia. Chlamydospores are
filled with oil globules and often abundant in culture.
Sexual reproduction is unknown.
Commentary: Species in the Umbelopsidales were
previously classified in Mucorales (e.g. U. isabellina)or
Mortierellales (e.g. Micromucor [5Umbelopsis]ramanni-
ana). Phylogenetic analyses of genome-scale data
resolve this as a distant sister group to Mucorales, con-
sistent with ordinal status. Like Mortierellales, species
of Umbelopsidales are frequently isolated from rhizo-
sphere soils, with increasing evidence that these fungi
occur as root endophytes (Hoff et al. 2004, Terhonen
et al. 2014).
Phylum: Zoopagomycota Gryganskyi,M.E.Smith,
Spatafora & Stajich, phylum nov.
MycoBank MB816300
Synonym: Zygomycota F. Moreau, Encyclopédie
Mycologique 23:2035. 1954 (pro parte).
Type: Zoopage Drechsler (1935).
Description: Phylum Zoopagomycota is erected here
to apply to all descendants of the node defined in the
reference phylogeny (FIG. 1) as the terminal Zoopago-
mycota clade. It is the least inclusive clade containing
Entomophthoromycotina, Kickellomycotina, and Zoo-
pagomycotina. Sexual reproduction, where known,
involves the production of zygospores by gametangial
conjugation. Morphologies associated with asexual
reproductive states include sporangia, merosporangia,
conidia, and chlamydospores.
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1035
Commentary. Zoopagomycota represents the earliest
diverging clade of zygomycetous fungi and formally
applies to the group referred to as zygomycetes II in the
INTRODUCTION. It comprises three subphyla in which
associations with animals (e.g. pathogens, commensals,
mutualists) form a common ecological theme, although
species from several lineages are mycoparasites (e.g. Syn-
cephalis,Piptocephalis, and Dimargaritales). Because of
its broader and more inclusive meaning, the name Zoo-
pagomycota (Gr.: zoo 5animal, pago 5frozen, ice or
unite) is preferred to other possible names for the clade
including Trichomycota R.T. Moore (1994), Basidiobolo-
mycota Doweld (2001), Entomophthoromycota Humber
(2012), and Harpellomycota Doweld (2013). All of these
alternative names were originally proposed to refer to
a particular clade within Zoopagomycota; therefore,
use of these alternative names would probably cause con-
fusion. Although some of the fungi in Zoopagomycota
can be maintained in axenic culture, most species are
more difficult to maintain in pure culture than species
of Mucoromycota. Accordingly, species of Zoopagomy-
cota are most frequently observed growing in association
with a host organism. Haustoria are produced by some of
the animal pathogens and mycoparasites. Zoopagomy-
cota hyphae may be compartmentalized by septa that
may be complete or uniperforate; in the latter, bifurcate
septa contain electron opaque lenticular plugs. Zygo-
spore formation typically involves modified hyphal tips,
thallus cells, or hyphal bodies (yeast-like cells) that func-
tion as gametangia.
Subphylum: Entomophthoromycotina Humber, in
Hibbett et al. Mycol. Res. 111:517. 2007.
Synonym: Entomophthoromycota Humber, Myco-
taxon 120:481. 2012.
Classes: Basidiobolomycetes Doweld, Prosyllabus
Tracheophytorum, Tentamen systematis plantarum
vascularium (Tracheophyta): LXXVII. 2001; Ento‐
mophthoromycetes Humber, Mycotaxon 120:486. 2012;
Neozygitomycetes Humber, Mycotaxon 120:485. 2012.
Orders: Basidiobolales Jacz. & P.A. Jacz., Opredelitel’
Gribov,(edn3)IFicomiţeti (Leningrad):8. 1931; Ento-
mophthorales G. Winter, Rabenh. Krypt.-Fl. 1:74. 1880;
Neozygitales Humber, Mycotaxon 120:486. 2012.
Commentary. Entomophthoromycotina includes three
classes and three orders of saprobic and insect pathogen-
ic fungi. The thallus may consist of coenocytic or septate
hyphae, which may fragment to form hyphal bodies,
or it may comprise only hyphal bodies. Asexual reproduc-
tion is by conidiogenesis from branched or unbranched
conidiophores; primary conidia are forcibly discharged
and secondary conidia are either forcibly or passively
released. Sexual reproduction involves the formation
of either zygospores by gametangial copulation, involving
hyphal compartments or hyphal bodies (Humber 2012).
Subphylum: Kickxellomycotina Benny, in Hibbett
et al. Mycol. Res. 111:518. 2007.
Synonym: Trichomycota R.T. Moore, Identifica‐
tion and Characterization of Pest Organisms:250. 1994
(pro parte).
Orders: Asellariales Manier ex Manier & Lichtw.,
Mycotaxon 7:442. 1978; Dimargaritales R.K. Benj., in
Kendrick (ed.), Whole Fungus 2:607. 1979; Harpellales
Lichtw. & Manier, Mycotaxon 7:441. 1978; Kickxellales
Kreisel ex R.K. Benj., in Kendrick (ed.), Whole Fungus
2:610. 1979; R.K. Benj., in Kendrick, ed., Whole Fun-
gus 2:607. 1979.
Commentary. Mycelium is regularly divided into com-
partments by bifurcate septa that often have lenticular
occlusions. Sexual reproduction involves the formation
of variously shaped zygospores by gametangial conjuga-
tion of relatively undifferentiated sexual hyphal com-
partments (Lichtwardt 1986). Sporophores may be
produced from septate, simple, or branched somatic
hyphae. Asexual reproduction involves the production
of uni- or multispored merosporangia arising from a
specialized vesicle (i.e. sporocladium), sporiferous
branchlets, or an undifferentiated sporophore apex.
Species may be saprobes, mycoparasites, and symbionts
of insects; the latter includes Harpellales that are typi-
cally found within the hindguts of aquatic life history
stages.
Subphylum: Zoopagomycotina Benny, in Hibbett
et al. Mycol. Res. 111:518. 2007.
Order: Zoopagales Bessey ex R.K. Benj., in Kendrick,
ed., Whole Fungus 2:590. 1979.
Commentary. Zoopagomycotina include mycopara-
sites and predators or parasites of small invertebrates
and amoebae. The hyphal diameter is characteristical-
ly narrow in thalli that are branched or unbranched;
sometimes specialized haustoria are produced in
association with hosts. Only a handful of species have
been successfully maintained in axenic culture. Sexual
reproduction, where known, is by gametangial conju-
gation, forming globose zygospores on apposed differ-
entiated or undifferentiated suspensor cells (Dreschler
1935). Asexual reproduction is by arthrospores, chla-
mydospores, conidia, or multispored merosporangia
that may be simple or branched.
DISCUSSION
Overview of Kingdom Fungi.
—
In the concatenated
RAxML analyses, we resolve and recognize seven
clades that we classify as phyla of Kingdom Fungi
(FIG. 1), with zoosporic fungi comprising the three ear-
liest diverging lineages. Cryptomycota, represented by
the genus Rozella, is the earliest diverging lineage of
Fungi followed by Chytridiomycota and Blastocladio-
mycota. The branching order of the latter two taxa is
1036 MYCOLOGIA
weakly supported and both have been resolved as shar-
ing a most recent common ancestor (MRCA) with the
nonflagellated fungi of Zoopagomycota, Mucoromy-
cota, and Dikarya (James et al. 2006, Chang et al.
2015). Within Chytridiomycota we recognize three
classes, including Chytridiomycetes Caval.-Sm. (1998),
Monoblepharidomycetes J.H. Schaffner (1909), and
Neocallimastigomycetes M.J. Powell (2007). The
remaining phyla of Fungi include the nonflagellated
phyla Zoopagomycota, Mucoromycota, Basidiomycota,
and Ascomycota. Because to the absence of genomic
data, we could not assess the validity of the newly
erected phylum Entorrhizomycota (Bauer et al 2015).
The 192 protein clusters incorporated into these
analyses are encoded by single to low-copy genes that
are conserved throughout eukaryotes (James et al.
2013). As such, these genes tend to be ubiquitously dis-
tributed in Fungi and arguably less susceptible to
errors associated with orthology assignment. The inter-
pretation of bootstrap support for branches in
genome-scale phylogenies is still poorly understood
given that some genes within a genome may have dif-
ferent evolutionary histories (e.g. Salichos et al.
2014). We attempted to alleviate this problem through
the use of conservative orthologs, but we cannot cur-
rently discount issues associated with ancient lineage
sorting events, whole genome duplications, and inad-
vertent biases associated with taxon sampling (e.g.
unsampled taxa, extinction events, etc.). In an attempt
to characterize the effect of ancient lineage sorting
events, ASTRAL analyses were performed on the boot-
strap trees derived from the RAxML analyses of each
protein sequence alignment. The placement of Blasto-
cladiomycota as sister group to the nonflagellated
lineages of Kingdom Fungi was supported by 56% BP
and 90% ABS values, suggesting that the node is not
characterized by high levels of ancient incomplete line-
age sorting but low levels of phylogenetic signal pres-
ent in the current dataset; a finding consistent with
the results of Chang et al. (2015). The effect of adding
taxa to fill the gaps among unsampled lineages is more
difficult to predict, but it is reasonable to assume that it
might increase support for long, relatively isolated
branches, such as Blastocladiomycota (Wiens and Mor-
rill 2011). At this time we consider the placement of
Blastocladiomycota unresolved.
Paraphyly of zygomycetes and support for major clades.
—
Both the concatenated RAxML (FIG. 1) and the
ASTRAL (FIG. 2) analyses reject zygomycete monophy-
ly and resolve two clades, Zoopagomycota and Mucor-
omycota, which form a paraphyletic grade from
which Dikarya are derived. Although this finding is
consistent with rDNA analyses (White et al. 2006) and
multigene phylogenies (James et al. 2006, Chang et al.
2015), it provides greater clarity on clade membership
and relationship to other major clades of Kingdom
Fungi. By not resurrecting the abandoned name Zygo-
mycota Moreau, we propose names for each of the two
monophyletic phyla and we expand the use of auto‐
typification based on validly published genera as
espoused by Hibbett et al. (2007). Because the Interna-
tional Code for algae, fungi, and plants (McNeill et al.
2012) does not require adherence to the principle of
priority above the rank of family, we have selected
names that communicate taxa or traits that are charac-
teristic of the majority of species contained within the
two phyla. In addition, the names Zoopagomycota
and Mucoromycota avoid taxonomic confusion stem-
ming from previous use of other names that are linked
to alternative evolutionary hypotheses. For example,
Glomeromycota has been used over the last 15 y to
refer to the monophyletic group of arbuscular mycor-
rhizal fungi (Schüßler et al. 2001); the use of this
name for a wider group of fungi would likely be prob-
lematic and confusing. Finally, we recognize the mini-
mum number of phylum-level clades necessary to
name monophyletic clades of zygomycetes to produce
a classification system that is easier to teach and
reduces the use of redundant taxa.
Zoopagomycota is resolved as the earliest diverging
lineage of zygomycetes. Although genomic sampling
included representatives from all three subphyla, a fur-
ther increase in taxon sampling will undoubtedly
reveal additional phylogenetic diversity. Kickxellomy-
cotina is represented by four taxa that are all from
Kickxellales. Entomophthoromycotina is represented
by five taxa, three from Entomophthorales (Conidiobo-
lus spp., Pandora formicae,Zoophthora radicans) and two
from Basidiobolales (B. heterosporus and B. meristos-
porus). Branch support (BP 589, ABS 582) for Ento-
mophthoromycotina is the lowest of the subphyla,
which is in part a result of the topological instability
of Basidiobolus. This finding is similar to observations
in previous multigene studies (Gryganskyi et al. 2012)
and suggests that more robust support for the place-
ment of Basidiobolus will not be achieved by the addi-
tion of sequence data alone but will instead require
additional taxon sampling, consideration of episodic
events associated with rare genomic changes, and pos-
sibly the use of models of evolution that are not strictly
bifurcating (Than et al. 2008). The sole representative
of Zoopagomycotina is Piptocephalis cylindrospora, for
which the sequence data were generated based on sin-
gle-cell genomics methods (Rinke et al. 2013). Its
membership in Zoopagomycota is strongly supported
by these analyses, but its placement within the phylum
is less well supported (MLBS 596, ABS 560). This is
possibly a consequence of the nature of the data from
single-cell sequencing and sparse taxon sampling for
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1037
the subphylum. As most species of Zoopagomycotina
are obligate symbionts, additional sampling will
require the use of advanced sequencing and computa-
tional techniques, use of dual-organism cultures and
novel approaches to establish axenic cultures.
Mucoromycota is resolved as the clade of zygomy-
cetes that diverged most recently from a shared ances-
tor with Dikarya. The most significant change from
previous molecular-based classifications of zygomycetes
(Schüßler et al. 2001) is the inclusion of Glomeromyco-
tina in Mucoromycota. Although Glomeromycotina
(5Glomeromycota) was previously resolved as more
closely related to Dikarya than Mucoromycotina and
Mortierellomycotina using nuclear SSU rDNA and
multigene sequence data (Schüßler et al. 2001, James
et al. 2006), this was not supported by the present anal-
yses. Rather, the topology presented here is consistent
with recent mitochondrial phylogenies (Nadimi et al.
2012, Pelin et al. 2012), genome-scale phylogenies,
and gene content analyses (Tisserant et al. 2013,
Chang et al. 2015), as well as with traditional morphol-
ogy-based classifications (Gerdemann and Trappe
1974, Morton and Benny 1990). As in previous studies
(Chang et al. 2015), the position of Glomeromycotina
is equivocal and it appears alternatively as the earliest
diverging lineage of the Mucoromycota (FIG.1,MLBS5
97) or as a sister group to Mortierellomycotina (FIG.2,
ABS 568). Mortierellomycotina is represented by the
genomes of two species of Mortierella; their placement
is consistent with being phylogenetically distinct from
Mucoromycotina. Because of the ease of their mainte-
nance in axenic culture, the strongly supported Mucor-
omycotina is sampled more and is represented by
11 taxa, two orders, and eight families. Although
represented only by a single taxon, Umbelopsidales
is supported as the sister clade to Mucorales, a find‐
ing consistent with multigene phylogenetic analyses
(Sekimoto et al. 2011, Hoffmann et al. 2013). Sugges-
tive of phylogenetic conflict among protein-sequence
trees within the Mucorales, several nodes within the
order are resolved differently between the RAxML
and ASTRAL analyses. Expanding the sampling density
throughout the Mucoromycota is needed to better
understand processes underlying molecular evolution
(e.g. possible genome duplications) around these
potentially problematic nodes.
Evolution of host association and nutritional modes.
—
Our
phylogenomic analysis shows a striking contrast between
the host associations and trophic modes of Zoopagomy-
cota and Mucoromycota (TABLE III). Most species of
Zoopagomycota are pathogens, parasites, or commen-
sals of animals and other fungi, whereas a few species
are considered to be more generalized saprobes (Benny
et al. 2014). Associations with living plants are rare for
TABLE III. Taxonomic distribution of selected morphological and ecological characters of zygomycete fungi
Zoopagomycotina Kickxellomycotina Entomophthoromycotina Mucoromycotina Mortierellomycotina Glomeromycotina
Sexual Reproduction Zygospore Zygospore Zygospore Zygospore Zygospore Unknown
Asexual Reproduction Sporangia, conidia Trichospores, sporangia,
merosporangia
Conidia Sporangia,
sporangioles
Sporangia Chlamydospore-like
Hyphae Coenocytic Bifurcate septa w/
lenticular plug
Complete septa,
bifurcate septa,
or coenocytic;
hyphal bodies
Coenocytic Coenocytic Coenocytic
MTOC
a
—
b
Centriole-like Centriole-like Spindle pole body ——
Hyphal tip structure —AVC
c
Spitzenkörper AVC AVC AVC
Fruiting body production Absent Absent Absent Present (rare) Present (rare) Present (rare)
Major host/substrate Amoeba, animal,
fungi
Animal, fungi Animal Plant Plant Plant
a
Microtubular Organizing Center.
b
Unsampled.
c
Apical Vesicle Crescent.
1038 MYCOLOGIA
the phylum. In contrast, Mucoromycota includes multi-
ple mycorrhizal lineages (Glomeromycotina, Endogo-
nales; Bidartondo et al. 2011, Redecker and Schüßler
2014), root endophytes (Mortierellomycotina, Umbe-
lopsidales; Hoff et al. 2004, Summerbell 2005, Terhonen
et al. 2014) and decomposers of plant-based carbon
sources (Mucorales; Benny et al. 2014). Members of
both Mucoromycotina and Glomeromycotina can also
form mycorrhiza-like relationships with nonvascular
plants (Field et al. 2015a). All species of Mucoromy‐
cotina known as mycoparasites (e.g. Spinellus fusiger,
Syzygites megalocarpa) or putative parasites of arthropods
(e.g. Sporodiniella umbellata) are evolutionarily derived
and closely related to saprobes (Hoffman et al. 2013).
In rare cases when species in Mucoromycota infect
humans or other animals, they are interpreted as oppor-
tunistic pathogens, typically of immunocompromised
individuals.
The phylogenetic distribution of these nutritional
associations illuminates two elements of fungal evolution
that shape the development of evolutionary hypotheses
of early diverging fungi. First, deep divergences among
Zoopagomycota point to an early origin for animal-
and fungus-associated nutritional relationships. Ancient
associations with animals, other fungi, and non-plant
organisms are poorly documented in the known fossil
record (Taylor et al. 2014) and our results predict hid-
den fungal associations yet to be detected through anal-
ysis of animal fossils. The second major point of
emphasis from these analyses is the sister-group relation-
ship of Mucoromycota and Dikarya and the diversifica-
tion of fungi in association with land plants. Dikarya
clearly diversified with land plants in terrestrial ecosys-
tems (Selosse and Le Tacon 1998, Berbee 2001). It is
now reasonable to consider that nutrition from land
plants had a deeper origin in fungal evolutionary history,
extending back to the common ancestor of Mucoromy-
cota and Dikarya. This is consistent with studies that
considered ancient fungal relationships with algae and
the land plant lineage (Chang et al. 2015, Field et al.
2015a). Furthermore, it is consistent with the record of
fossil fungi from some of the earliest 407 million year
old land plants. Such fossils include arbuscules charac-
teristic of the Glomeromycotina (Glomites rhyniensis;Tay-
lor et al. 1995), swellings and hyphae reminiscent of
Mucoromycotina (Strullu-Derrien et al. 2014) and spor-
ocarps suggestive of Dikarya (Paleopyrenomycites devonicus;
Taylor et al. 2005). It has been hypothesized that symbi-
oses with heterotrophic fungi played a role the evolution
of land plants (Bidartondo et al. 2011, Field et al.
2015b). Our results specify the plant-associated, terrestri-
al MRCA of Mucoromycota plus Dikarya as the species
that gave rise to independent and parallel origins of
important plant-fungal symbioses from endophytes to
mycorrhizae.
Evolution of morphology.
—
Interpretation of morphology
in the context of this genome-scale phylogeny high-
lights the importance of Zoopagomycota, Mucoromy-
cota, and their MRCA in understanding the evolution
of fungal traits associated with the flagellum, hyphae,
reproduction, and multicellularity. We provide a brief
summary of these traits with an emphasis on develop-
ment and refinement of evolutionary hypotheses, but
direct readers to more comprehensive treatments for
detailed discussions (Humber 2012, Benny et al.
2014, Redecker and Schüßler 2014, McLaughlin
et al. 2015).
Although these analyses resolve a single loss of the
flagellum in the MRCA of Zoopagomycota, Mucoromy-
cota, and Dikarya, it should be noted that numerous
lineages were not sampled here and their inclusion
would indicate additional losses of the flagellum
among early diverging fungi. Microsporidia are sister
group to Cryptomycota and represent the loss of the
flagellum in the earliest diverging lineage of Fungi
(James et al. 2013). Similarly, Hyaloraphidium is a non-
flagellated member of Chytridiomycota and represents
a loss of the flagellum among the core clade of zoo-
sporic fungi (James et al. 2006). Relevant to the zygo-
mycete fungi is Olpidium, a genus of zoosporic fungi
that has been hypothesized to be closely related to
Zoopagomycota based on multigene phylogenies
(Sekimoto et al. 2001, James et al. 2006). Analysis of
genomic data for this genus is crucial to more accu-
rately estimate the number of losses of flagellum, their
placement on the fungal tree of life, and to test alter-
native hypotheses of a single loss of the flagellum
(Liu et al. 2006). Furthermore, the placement of Zoo-
pagomycota as the earliest diverging lineage of nonfla-
gellated fungi is intriguing because some of its species
have retained what may be relicts of a flagellum in the
form of cylindrical, centriole-like organelles. Centriole-
like organelles are associated with the nuclei of Basidio-
bolus of Entomophthoromycotina (McKerracher and
Heath 1985, Roberson et al. 2011) and Coemansia of
Kickxellomycotina (McLaughlin et al. 2015). In con-
trast to these centriole-like organelles, Mucoromycotina
and Dikarya share discoidal to hemispherical spindle
pole bodies. Although spindle pole bodies function as
microtubule organizing centers, as do centrioles, they
lack any obvious remnant of the centrioles’character-
istic 9+2 microtubule arrangement (reviewed in
McLaughlin et al. 2015). Broader analyses are needed,
but the distribution of putative relict centrioles is con-
sistent with flagellum loss occurring shortly before or
during the diversification of Zoopagomycota.
Hyphae vary among species and clades in Mucoro-
mycota and Zoopagomycota. Species of Zoopagomyco-
tina typically produce small diameter coenocytic
hyphae and haustoria in association with parasitism
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1039
of hosts. Species of Kickxellomycotina produce hyphae
that are regularly compartmentalized by uniperforate,
bifurcate septa occluded by lenticular plugs (Jeffries
and Young 1979, Saikawa 1989). Species of Ento-
mophthoromycotina produce either coenocytic hyphae,
hyphae with complete septa that may disarticulate into
one or two-celled hyphal bodies (reviewed in Humber
2012), or with septa similar to those of Kickxellomyco-
tina (Saikawa 1989). Species of Mucoromycotina and
Mortierellomycotina produce large diameter, coeno-
cytic hyphae characteristic of textbook zygomycetes,
as do Glomeromycotina, which in addition make high-
ly branched, narrow hyphal arbuscules in host cells.
Where septations do occur in Mucoromycota they
tend to be adventitious and formed at the base of
reproductive structures.
The Spitzenkörper is associated with hyphal growth
in Dikarya but has been elucidated for only a few
species of zygomycetes. Roberson et al. (2011) docu-
mented an apical spherical organization of microvesi-
cles in Basidiobolus (Zoopagomycota) consistent with
a Spitzenkörper. In contrast, hyphae of Coemansia
(Zoopagomycota) and Gilbertella,Mortierella, and Mucor
(Mucoromycota) (Fisher and Roberson 2016) and the
germ tubes of Gigaspora (Mucoromycota) (Bentivenga
et al. 2013) lack a classical Spitzenkörper, but instead
possess a hemispherical organization of vesicles, the
apical vesicle crescent, which in some taxa has been
demonstrated to be mandatory for hyphal growth
(Fisher and Roberson 2016).
Asexual reproduction by sporangia is present in all
subphyla of Zoopagomycota and Mucoromycota with
three notable exceptions (Benny et al. 2014). Ento-
mophthoromycotina is characterized by the produc-
tion of conidia with the formation of forcibly
discharged primary conidia that may undergo germi-
nation to form passively dispersed secondary conidia
(Humber 2012). Conidia are also described for species
in Zoopagomycotina that are pathogenic to amoebae
and nematodes (Dreschler 1935, 1936), but mycopara-
sitic lineages produce reduced sporangia, sporan-
gioles, and merosporangia (Benny et al. 2014).
Presumably, conidiogenesis in Zoopagomycota and
Dikarya arose independently, but closer analysis may
yet reveal homologies at the level of molecular devel-
opment. Glomeromycotina are known to reproduce
only asexually via unique spores that resemble chlamy-
dospores or azygospores.
Where sexual reproduction is known in species of
both Zoopagomycota and Mucoromycota, it is by the
formation of zygospores via gametangial conjugation
(Drechsler 1935, Lichtwardt 1986, Humber 2012). In
Mucoromycota, sexual reproduction is under the con-
trol of mating type genes, sexP and sexM, which regu-
late the production of pheromones required for the
maturation of hyphae into gametangia (Idnurm et al.
2008) and confer +and –mating-type identity, respec-
tively (reviewed in Lee et al. 2010). Recent genomic
studies have revealed numerous mating genes in the
genomes of Glomeromycotina (Riley et al. 2013) and
a Dikarya-like mating processes in R. irregularis (Ropars
et al. 2016), suggesting that they may have a cryptic
sexual cycle. In Zoopagomycota, the genetic basis and
physiological control of mating has not been charac-
terized. From commonalities across fungal phyla
(Cassleton 2008), we assume that genetic systems in
Zoopagomycota and Mucoromycota might be similar,
but detailed studies are needed.
Multicellular sporocarps are not produced by Zoo-
pagomycota and though rare, they are present within
Mucoromycota through independent origins in Endo-
gone (Mucoromycotina; Bidartondo et al. 2011), Modi-
cella (Mortierellomycotina; Smith et al. 2013) and as
aggregations of spore-producing hyphae and spores
in species of Glomeromycotina (Gerdemann and
Trappe 1974, Redecker and Schüßler 2014). Along
with the multicellular sporocarps in Agaricomycotina
(Basidiomycota) and Pezizomycotina (Ascomycota),
multicellular sporocarps within Mucoromycota have
been derived independently, suggesting that while
the genetic and metabolic potential for complex thal-
lus diversity did not arise until the MRCA of Mucoro-
mycota and Dikarya, it then resulted in multiple
independent origins of complex spore-producing
structures involving hyphal differentiation (Stajich
et al. 2009).
ACKNOWLEDGMENTS
This paper is dedicated to our colleague and coauthor
Thomas N. Taylor who passed away during the final prepara-
tion of this manuscript. The authors thank the following per-
sons for access to unpublished genomes: Santiago Torres
Martínez for Mucor circinelloides, Teresa Pawlowska and Ste-
phen Mondo for Rhizopus microsporus var. microsporus, Vincent
Bruno for Basidiobolus heterosporus and Saksenaea vasiformis,
and Francis Martin for Mortierella elongata. This material
is based upon work supported by the National Science
Foundation (DEB-1441604 to JWS, DEB-1441715 to JES,
DEB-1441677 to TYJ, DEB-1441728 to RWR), the French
National Research Agency through the Laboratory of Excel-
lence ARBRE (grant No. ANR–11–LBX–0002–01 to JWS)
and the Canadian National Science and Engineering
Research Council grants (412318-11 and 138427-11 to
MLB). Any opinions, findings and conclusions or recommen-
dations expressed in this material are those of the author(s)
and do not necessarily reflect the views of the National Sci-
ence Foundation. Mention of trade names or commercial
products in this publication is solely for the purpose of pro-
viding specific information and does not imply recommenda-
tion or endorsement by the US Department of Agriculture.
USDA is an equal opportunity provider and employer.
1040 MYCOLOGIA
LITERATURE CITED
Adams MD, Celniker SE, Holt RA, Evans CA, Gocayne JD,
Amanatides PG, Scherer SE, Li PW, Hoskins RA, Galle
RF, George RA, Lewis SE, Richards S, Ashburner M,
Henderson SN, Sutton GG, Wortman JR, Yandell MD,
Zhang Q, Chen LX, Brandon RC, Rogers YH, Blazej
RG, Champe M, Pfeiffer BD, Wan KH, Doyle C, Baxter
EG, Helt G, Nelson CR, Gabor GL, Abril JF, Agbayani
A, An HJ, Andrews-Pfannkoch C, Baldwin D, Ballew
RM, Basu A, Baxendale J, Bayraktaroglu L, Beasley EM,
Beeson KY, Benos PV, Berman BP, Bhandari D, Bolsha-
kov S, Borkova D, Botchan MR, Bouck J, Brokstein P,
Brottier P, Burtis KC, Busam DA, Butler H, Cadieu E,
Center A, Chandra I, Cherry JM, Cawley S, Dahlke C,
Davenport LB, Davies P, de Pablos B, Delcher A, Deng
Z, Mays AD, Dew I, Dietz SM, Dodson K, Doup LE,
Downes M, Dugan-Rocha S, Dunkov BC, Dunn P, Dur-
bin KJ, Evangelista CC, Ferraz C, Ferriera S, Fleisch-
mann W, Fosler C, Gabrielian AE, Garg NS, Gelbart
WM, Glasser K, Glodek A, Gong F, Gorrell JH, Gu Z,
Guan P, Harris M, Harris NL, Harvey D, Heiman TJ,
Hernandez JR, Houck J, Hostin D, Houston KA, How-
land TJ, Wei MH, Ibegwam C, Jalali M, Kalush F, Karpen
GH, Ke Z, Kennison JA, Ketchum KA, Kimmel BE,
Kodira CD, Kraft C, Kravitz S, Kulp D, Lai Z, Lasko P,
Lei Y, Levitsky AA, Li J, Li Z, Liang Y, Lin X, Liu X, Mat-
tei B, McIntosh TC, McLeod MP, McPherson D, Merku-
lov G, Milshina NV, Mobarry C, Morris J, Moshrefi A,
Mount SM, Moy M, Murphy B, Murphy L, Muzny DM,
Nelson DL, Nelson DR, Nelson KA, Nixon K, Nusskern
DR, Pacleb JM, Palazzolo M, Pittman GS, Pan S, Pollard
J, Puri V, Reese MG, Reinert K, Remington K, Saunders
RD, Scheeler F, Shen H, Shue BC, Sidén-Kiamos I, Simp-
son M, Skupski MP, Smith T, Spier E, Spradling AC, Sta-
pleton M, Strong R, Sun E, Svirskas R, Tector C, Turner
R, Venter E, Wang AH, Wang X, Wang ZY, Wassarman
DA, Weinstock GM, Weissenbach J, Williams SM, Woo-
dageT, Worley KC, Wu D, Yang S, Yao QA, Ye J, Yeh
RF, Zaveri JS, Zhan M, Zhang G, Zhao Q, Zheng L,
Zheng XH, Zhong FN, Zhong W, Zhou X, Zhu S,
Zhu X, Smith HO, Gibbs RA, Myers EW, Rubin GM,
Venter JC. The genome sequence of Drosophila melanoga-
ster. Science 287:2185–2195, doi:10.1126/science.287.
5461.2185
Bauer R, Garnica S, Oberwinkler F, Reiss K, Weiß M,
Begerow D. 2015. Entorrhizomycota: a new fungal phy-
lum reveals new perspectives on the evolution of fungi.
PLoS One 10:e0128183, doi:10.1371/journal.pone.
0128183
———, Humber RA, Voigt K. 2014. Zygomycetous fungi:
phylum Entomophthoromycota and subphyla Kickxello-
mycotina, Mortierellomycotina, Mucoromycotina, and
Zoopagomycotina. In: McLaughlin DJ, Spatafora JW,
eds. Systematics and evolution. Part A. New York: Spring-
er-Verlag. The Mycota VII:209–250.
Benny GL, Humber RA, Voigt K. 2014. Zygomycetous fungi:
phylum Entomophthoromycota and subphyla Kickxello-
mycotina, Mortierellomycotina, Mucoromycotina, and
Zoopagomycotina. In: McLaughlin DJ, Spatafora JW,
eds. Mycota VII, part A. Systematics and evolution. New
York: Springer-Verlag. p 209–250.
———,O’Donnell K. 2000. Amoebidium parasiticum is a proto-
zoan, not a Trichomycete. Mycologia 92:1133–1137,
doi:10.2307/3761480
Bentivenga SP, Kumar TKA, Kumar L, Roberson RW,
McLaughlin DJ. 2013. Cellular organization in germ
tube tips of Gigaspora and its phylogenetic implications.
Mycologia 105:1087–1099, doi:10.3852/12-291
Berbee ML. 2001. The phylogeny of plant and animal patho-
gens in the Ascomycota. Physiol Mol Plant Pathol
59:165–187, doi:10.1006/pmpp.2001.0355
———, Taylor JW. 2010. Dating the molecular clock in
fungi—how close are we? Fungal Biol Rev 24:1–16,
doi:10.1016/j.fbr.2010.03.001
Bianciotto V, Lumini E, Bonfante P, Vandamme P. 2003.
“Candidatus Glomeribacter gigasporarum”gen. nov., sp.
nov., an endosymbiont of arbuscular mycorrhizal fungi.
Int J Syst Evol Micrbiol 53:121–124, doi:10.1099/
ijs.0.02382-0
Bidartondo MI, Read DJ, Trappe JM, Merckx V, Ligrone R,
Duckett JG. 2011. The dawn of symbiosis between plants
and fungi. Biol Lett 7:574–577, doi:10.1098/rsbl.
2010.1203
Cafaro MJ. 2005. Eccrinales (Trichomycetes) are not fungi,
but a clade of protists at the early divergence of animals
and fungi. Mol Phylogenet Evol 35:21–34, doi:10.1016/j.
ympev.2004.12.019
Cantino P. 2010. International Code of phylogenetic nomen-
clature. 102 p.
Capella-Gutiérrez S, Silla-Martínez JM, Gabaldón T. 2009.
TrimAl: a tool for automated alignment trimming in
large-scale phylogenetic analyses. Bioinformatics 25:
1972–1973, doi:10.1093/bioinformatics/btp348
Casselton LA. 2008. Fungal sex genes—searching for the
ancestors. Bioessays 30:711–714, doi:10.1002/bies.20782
Chang Y, Wang S, Sekimoto S, Aerts AL, Choi C, Clum A,
LaButti KM, Lindquist EA, Yee Ngan C, Ohm RA, Sala-
mov AA, Grigoriev IV, Spatafora JW, Berbee ML. 2015.
Phylogenomic analyses indicate that early fungi evolved
digesting cell walls of algal ancestors of land plants.
Genome Biol Evol 7:1590–1601, doi:10.1093/gbe/
evv090
Corrochano LM, Kuo A, Marcet-Houben M, Polaino S, Sala-
mov A, Villalobos-Escobedo JM, Grimwood J, Álvarez
MI, Avalos J, Bauer D, Benito EP, Benoit I, Burger G,
Camino LP, Cánovas D, Cerdá-Olmedo E, Cheng JF,
Domínguez A, EliášM, Eslava AP, Glaser F, Gutiérrez
G, Heitman J, Henrissat B, Iturriaga EA, Lang BF, Lavín
JL, Lee SC, Li W, Lindquist E, López-García S, Luque
EM, Marcos AT, Martin J, McCluskey K, Medina HR,
Miralles-Durán A, Miyazaki A, Muñoz-Torres E, Oguiza
JA, Ohm RA, Olmedo M, Orejas M, Ortiz-Castellanos
L, Pisabarro AG, Rodríguez-Romero J, Ruiz-Herrera J,
Ruiz-Vázquez R, Sanz C, Schackwitz W, Shahriari M,
Shelest E, Silva-Franco F, Soanes D, Syed K, Tagua VG,
Talbot NJ, Thon MR, Tice H, de Vries RP, Wiebenga
A, Yadav JS, Braun EL, Baker SE, Garre V, Schmutz J,
Horwitz BA, Torres-Martínez S, Idnurm A, Herrera-
Estrella A, Gabaldón T, Grigoriev IV. Expansion of
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1041
signal transduction pathways in fungi by extensive
genome duplication. Curr Biol 26:1–8.
Desiro A, Faccio A, Kaech A, Bidartondo MI, Bonfante P.
2014. Endogone, one of the oldest plant-associated fungi,
host unique Mollicutes-related endobacteria. New Phytol
205:1464–1472, doi:10.1111/nph.13136
Dickie IA, Alexander I, Lennon S, Öpik M, Selosse MA, van
der Heijden MGA, Martin FM. 2015. Evolving insights
to understanding mycorrhizas. New Phytol 205:1369–
1374, doi:10.1111/nph.13290
Doggett JS, Wong B. 2014. Mucormycosis. In: Loriaux L, ed.
Endocrine emergencies. New York: Humana Press.
p57–63.
Dreschler C. 1935. Some conidial phycomycetes destructive
to terricolous amoebae. Mycologia 27:6–40, doi:10.
2307/3754021
———. 1936. New conidial phycomycetes destructive to terri-
colous amoebae. Mycologia 28:363–389, doi:10.2307/
3754001
Dujon B, Shermann D, Fischer G, Durrens P, et al. 2004.
Genome evolution in yeasts. Nature 430:35–44, doi:
10.1038/nature02579
Duplessis S, Cuoma CA, Lin YC, Aerts A, et al. 2011. Obligate
biotrophy features unraveled by the genomic analysis of
rust fungi. Proc Natl Acad Sci USA 108:9166–9171,
doi:10.1073/pnas.1019315108
Ebersberger I, de Matos Simoes R, Kupczok A, Gube M,
Kothe E, Voigt K, Haeseler von A. 2012. A consistent
phylogenetic backbone for the fungi. Mol Biol Evol
29:1319–1334, doi:10.1093/molbev/msr285
Eddy SR. 2011. Accelerated profile HMM searches. PLoS
Comput Biol 7:e1002195, doi:10.1371/journal.pcbi.
1002195
Field KJ, Pressel S, Duckett JG, Rimington WR, Bidartondo
MI. 2015b. Symbiotic options for the conquest of land.
Trends Ecol Evol 30:477–486, doi:10.1016/j.tree.2015.
05.007
———, Rimington WR, Bidartondo MI, Allinson KE, Beer-
ling DJ, Cameron DD, Duckett JG, Leake JR, Pressel S.
2015a. First evidence of mutualism between ancient
plant lineages (Haplomitriopsida liverworts) and
Mucoromycotina fungi and its response to simulated
Palaeozoic changes in atmospheric CO
2
. New Phytol
205:743–756, doi:10.1111/nph.13024
Fisher KE, Roberson RW. 2016. Hyphal tip cytoplasmic orga-
nization in four zygomycetous fungi. Mycologia 108:
533–542, doi:10.3852/15-226
Floudas D, Binder M, Riley R, Barry K, Blanchette RA, Hen-
rissat B, Martínez AT, Otillar R, Spatafora JW, Yadav JS,
Aerts A, Benoit I, Boyd A, Carlson A, Copeland A, Cou-
tinho PM, de Vries RP, Ferreira P, Findley K, Foster B,
Gaskell J, Glotzer D, Górecki P, Heitman J, Hesse C,
Hori C, Igarashi K, Jurgens JA, Kallen N, Kersten P, Koh-
ler A, Kües U, Kumar TK, Kuo A, LaButti K, Larrondo
LF, Lindquist E, Ling A, Lombard V, Lucas S, Lundell
T, Martin R, McLaughlin DJ, Morgenstern I, Morin E,
Murat C, Nagy LG, Nolan M, Ohm RA, Patyshakuliyeva
A, Rokas A, Ruiz-Dueñas FJ, Sabat G, Salamov A, Same-
jima M, Schmutz J, Slot JC, St John F, Stenlid J, Sun H,
Sun S, Syed K, Tsang A, Wiebenga A, Young D, Pisabarro
A, Eastwood DC, Martin F, Cullen D, Grigoriev IV, Hib-
bett DS. 2012. The Paleozoic origin of enzymatic lignin
decomposition reconstructed from 31 fungal genomes.
Science 336:1715–1719, doi:10.1126/science.1221748
Galagan JE, Calvo SE, Borkovich KA, Selker EU, Read ND,
Jaffe D, FitzHugh W, Ma LJ, Smirnov S, Purcell S, Reh-
man B, Elkins T, Engels R, Wang S, Nielsen CB, Butler
J, Endrizzi M, Qui D, Ianakiev P, Bell-Pedersen D, Nel-
son MA, Werner-Washburne M, Selitrennikoff CP, Kin-
sey JA, Braun EL, Zelter A, Schulte U, Kothe GO, Jedd
G, Mewes W, Staben C, Marcotte E, Greenberg D, Roy
A, Foley K, Naylor J, Stange-Thomann N, Barrett R,
Gnerre S, Kamal M, Kamvysselis M, Mauceli E, Bielke
C, Rudd S, Frishman D, Krystofova S, Rasmussen C, Met-
zenberg RL, Perkins DD, Kroken S, Cogoni C, Macino
G, Catcheside D, Li W, Pratt RJ, Osmani SA, DeSouza
CP, Glass L, Orbach MJ, Berglund JA, Voelker R, Yarden
O, Plamann M, Seiler S, Dunlap J, Radford A, Aramayo
R, Natvig DO, Alex LA, Mannhaupt G, Ebbole DJ, Frei-
tag M, Paulsen I, Sachs MS, Lander ES, Nusbaum C, Bir-
ren B. 2003. The genome sequence of the filamentous
fungus Neurospora crassa. Nature 422:859–868, doi:
10.1038/nature01554
Gerdemann J, Trappe JM. 1974. The Endogonaceae in the
Pacific Northwest. Mycol Mem 5:1–76.
Goffeau A, Barrell BG, Bussey H, Davis RW, Dujon B, Feld-
mann H, Galibert F, Hoheisel JD, Jacq C, Johnston M,
Louis EJ, Mewes HW, Murakami Y, Philippsen P, Tette-
lin H, Oliver SG. Life with 6000 genes. Science
274:546–567, doi:10.1126/science.274.5287.546
Gryganskyi AP, Humber RA, Smith ME, Miadlikowska J, Mia-
dlikovska J, Wu S, Voigt K, Walther G, Anishchenko IM,
Vilgalys R. 2012. Molecular phylogeny of the Ento-
mophthoromycota. Mol Phylogenet Evol 65:682–694,
doi:10.1016/j.ympev.2012.07.026
———, Muszewska A. 2014. Whole genome sequencing and
the Zygomycota. Fungal Genom Biol 4:e116,
doi:10.4172/2165-8056.1000e116
Hibbett DS, Binder M, Bischoff JF, Blackwell M, Cannon PF,
Eriksson OE, Huhndorf S, James T, Kirk PM, Lücking R,
Thorsten Lumbsch H, Lutzoni F, Matheny PB,
McLaughlin DJ, Powell MJ, Redhead S, Schoch CL, Spa-
tafora JW, Stalpers JA, Vilgalys R, Aime MC, Aptroot A,
Bauer R, Begerow D, Benny GL, Castlebury LA, Crous
PW, Dai YC, Gams W, Geiser DM, Griffith GW, Gueidan
C, Hawksworth DL, Hestmark G, Hosaka K, Humber
RA, Hyde KD, Ironside JE, Kõljalg U, Kurtzman CP,
Larsson KH, Lichtwardt R, Longcore J, Miadlikowska J,
Miller A, Moncalvo JM, Mozley-Standridge S, Oberwink-
ler F, Parmasto E, Reeb V, Rogers JD, Roux C, Ryvarden
L, Sampaio JP, Schüssler A, Sugiyama J, Thorn RG,
Tibell L, Untereiner WA, Walker C, Wang Z, Weir A,
Weiss M, White MM, Winka K, Yao YJ, Zhang N. 2007.
A higher-level phylogenetic classification of the Fungi.
Mycol Res 111:509–547, doi:10.1016/j.mycres.2007.
03.004
Higashiyama K, Fujikawa S, Park EY. 2002. Production of ara-
chidonic acid by Mortierella fungi. Biotechnol Bioprocess
Eng 7:252–262, doi:10.1007/BF02932833
1042 MYCOLOGIA
Hoff JA, Klopfenstein NB, McDonald GI. 2004. Fungal endo-
phytes in woody roots of Douglas‐fir (Pseudotsuga menzie-
sii) and ponderosa pine (Pinus ponderosa). For Pathol
34:255–271, doi:10.1111/j.1439-0329.2004.00367.x
Hoffmann K, Voigt K, Kirk PM. 2011. Mortierellomycotina
subphyl. nov., based on multi-gene genealogies. Myco-
taxon 115:353–363, doi:10.5248/115.353
———, Pawłowska J, Walther G. 2013. The family structure
of the Mucorales: a synoptic revision based on compre-
hensive multigene-genealogies. Persoonia 30:57–76,
doi:10.3767/003158513X666259
Humber RA. 2012. Entomophthoromycota: a new phylum
and reclassification for entomophthoroid fungi. Myco-
taxon 120:477–492, doi:10.5248/120.477
Idnurm A, Walton FJ, Floyd A, Heitman J. 2008. Identifica-
tion of the sex genes in an early diverged fungus. Nature
451:193–196, doi:10.1038/nature06453
James TY, Kauff F, Schoch CL, Matheny PB, Hofstetter V,
Cox CJ, Celio G, Gueidan C, Fraker E, Miadlikowska J,
Lumbsch HT, Rauhut A, Reeb V, Arnold AE, Amtoft A,
Stajich JE, Hosaka K, Sung GH, Johnson D, O’Rourke
B, Crockett M, Binder M, Curtis JM, Slot JC, Wang Z,
Wilson AW, Schüssler A, Longcore JE, O’Donnell K,
Mozley-Standridge S, Porter D, Letcher PM, Powell MJ,
Taylor JW, White MM, Griffith GW, Davies DR, Humber
RA, Morton JB, Sugiyama J, Rossman AY, Rogers JD, Pfis-
ter DH, Hewitt D, Hansen K, Hambleton S, Shoemaker
RA, Kohlmeyer J, Volkmann-Kohlmeyer B, Spotts RA,
Serdani M, Crous PW, Hughes KW, Matsuura K, Langer
E, Langer G, Untereiner WA, Lücking R, Büdel B, Gei-
ser DM, Aptroot A, Diederich P, Schmitt I, Schultz M,
Yahr R, Hibbett DS, Lutzoni F, McLaughlin DJ, Spata-
fora JW, Vilgalys R. 2006. Reconstructing the early evolu-
tion of Fungi using a six-gene phylogeny. Nature
443:818–822, doi:10.1038/nature05110
———, Pelin A, Bonen L, Ahrendt S, Sain D, Corradi N, Sta-
jich JE. 2013. Shared signatures of parasitism and phylo-
genomics unite Cryptomycota and microsporidia. Curr
Biol 23:1548–1553, doi:10.1016/j.cub.2013.06.057
Jeffries P, Young T. 1979. Ultrastructure of septa in Dimar-
garis cristalligena RK Benjamin. J Gen Microbiol 111:
303–311, doi:10.1099/00221287-111-2-303
Jennessen J, Schnürer J, Olsson J, Samson RA, Dijksterhuis J.
2008. Morphological characteristics of sporangiospores
of the tempe fungus Rhizopus oligosporus differentiate it
from other taxa of the R. microsporus group. Mycol Res
112:547–563, doi:10.1016/j.mycres.2007.11.006
Joneson S, Stajich JE, Shiu SH, Rosenblum EB. 2011. Geno-
mic transition to pathogenicity in chytrid fungi. PLoS
Pathog 7:e1002338.
Kamper J, Kahmann R, Bolker M, Ma LJ, Brefort T, Saville BJ,
Banuett F, Kronstad JW, Gold SE, Müller O, Perlin MH,
Wösten HA, de Vries R, Ruiz-Herrera J, Reynaga-Peña
CG, Snetselaar K, McCann M, Pérez-Martín J, Feld-
brügge M, Basse CW, Steinberg G, Ibeas JI, Holloman
W, Guzman P, Farman M, Stajich JE, Sentandreu R,
González-Prieto JM, Kennell JC, Molina L, Schirawski J,
Mendoza-Mendoza A, Greilinger D, Münch K, Rössel
N, Scherer M, Vranes M, Ladendorf O, Vincon V, Fuchs
U, Sandrock B, Meng S, Ho EC, Cahill MJ, Boyce KJ,
Klose J, Klosterman SJ, Deelstra HJ, Ortiz-Castellanos
L, Li W, Sanchez-Alonso P, Schreier PH, Häuser-Hahn
I, Vaupel M, Koopmann E, Friedrich G, Voss H, Schlüter
T, Margolis J, Platt D, Swimmer C, Gnirke A, Chen F,
Vysotskaia V, Mannhaupt G, Güldener U, Münsterkötter
M, Haase D, Oesterheld M, Mewes HW, Mauceli EW,
DeCaprio D, Wade CM, Butler J, Young S, Jaffe DB,
Calvo S, Nusbaum C, Galagan J, Birren BW. 2006.
Insights from the genome of the biotrophic fungal plant
pathogen Ustilago maydis. Nature 444:97–101, doi:
10.1038/nature05248
King N, Westbrook MJ, Young SL, Kuo A, Abedin M, Chap-
man J, Fairclough S, Hellsten U, Isogai Y, Letunic I,
Marr M, Pincus D, Putnam N, Rokas A, Wright KJ,
Zuzow R, Dirks W, Good M, Goodstein D, Lemons D,
Li W, Lyons JB, Morris A, Nichols S, Richter DJ, Salamov
A, Sequencing JG, Bork P, Lim WA, Manning G, Miller
WT, McGinnis W, Shapiro H, Tjian R, Grigoriev IV,
Rokhsar D. The genome of the choanoflagellate Mono-
siga brevicollis and the origin of metazoans. Nature 451:
783–788.
Kohler A, Kuo A, Nagy LG, Morin E, Barry KW, Buscot F,
Canbäck B, Choi C, Cichocki N, Clum A, Colpaert J,
Copeland A, Costa MD, Doré J, Floudas D, Gay G, Gir-
landa M, Henrissat B, Herrmann S, Hess J, Högberg N,
Johansson T, Khouja HR, LaButti K, Lahrmann U,
Levasseur A, Lindquist EA, Lipzen A, Marmeisse R, Mar-
tino E, Murat C, Ngan CY, Nehls U, Plett JM, Pringle A,
Ohm RA, Perotto S, Peter M, Riley R, Rineau F, Ruytinx
J, Salamov A, Shah F, Sun H, Tarkka M, Tritt A,
Veneault-Fourrey C, Zuccaro A; Mycorrhizal Genomics
Initiative Consortium, Tunlid A, Grigoriev IV, Hibbett
DS, Martin F. 2015. Convergent losses of decay mechan-
isms and rapid turnover of symbiosis genes in mycor-
rhizal mutualists. Nat Genet 47:410–415, doi:10.1038/
ng.3223
Lee SC, Ni M, Li W, Shertz C, Heitman J. 2010. The evolution
of sex: a perspective from the fungal kingdom. Micro-
biol Mol Biol Rev 74:298–340, doi:10.1128/MMBR.
00005-10
Lichtwardt RW. 1986. The Trichomycetes: fungal associates
of arthropods. New York: Springer-Verlag. 343 p.
Liu Y, Hodson MC, Hall BD. 2006. Loss of flagellum hap-
pened only once in the fungal lineage: phylogenetic
structure of Kingdom Fungi inferred from RNA poly-
merase II subunit genes. BMC Evol Biol 6:74,
doi:10.1186/1471-2148-6-74
———, Steenkamp ET, Brinkmann H, Forget L, Philippe H,
Lang BF. 2009. Phylogenomic analyses predict sis-
tergroup relationship of nucleariids and fungi and para-
phyly of zygomycetes with significant support. BMC Evol
Biol 9:272, doi:10.1186/1471-2148-9-272
Loftus BJ, Fung E, Roncaglia P, Rowley D, et al. 2005. The
genome of the basidiomycetous yeast and human patho-
gen Cryptococcus neoformans. Science 307:1321–1324, doi:
10.1126/science.1103773
Ma LJ, Ibrahim AS, Skory C, Grabherr MG, Burger G, Butler
M, Elias M, Idnurm A, Lang BF, Sone T, Abe A, Calvo
SE, Corrochano LM, Engels R, Fu J, Hansberg W, Kim
JM, Kodira CD, Koehrsen MJ, Liu B, Miranda-Saavedra
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1043
D, O’Leary S, Ortiz-Castellanos L, Poulter R, Rodriguez-
Romero J, Ruiz-Herrera J, Shen YQ, Zeng Q, Galagan J,
Birren BW, Cuomo CA, Wickes BL. 2009. Genomic anal-
ysis of the basal lineage fungus Rhizopus oryzae reveals a
whole-genome duplication. PLoS Genet 5:e1000549,
doi:10.1371/journal.pgen.1000549
McKerracher LJ, Heath IB, 1985. The structure and cycle of
thenucleus-associated organelle in two species of Basidio-
bolus. Mycologia 77:412–417, doi:10.2307/3793197
McLaughlin DJ, Healy RA, Celio GJ, Roberson RW, Kumar
TKA. 2015. Evolution of zygomycetous spindle pole bod-
ies: evidence from Coemansia reversa mitosis. Am J Bot
102:707–717, doi:10.3732/ajb.1400477
McNeill J, Barrie FF, Buck WR, Demoulin V, Greuter W,
Hawksworth DL, Herendeen PS, Knapp S, Marhold K,
Prado J, Prud’homme van Reine WF, Smith GF, Wier-
sema JH, Turland N, eds. 2012. International code of
nomenclature for algae, fungi, and plants (Melbourne
code). [Regnum Vegetabile no. 154.] Königstein: Koeltz
Scientific Books. 208 p.
Mirarab S, Reaz R, Bayzid MS, Zimmermann T. 2014.
ASTRAL: Genome-scale coalescent-based species tree
estimation. Bioinformatics 30:i541–i548, doi:10.1093/
bioinformatics/btu462
Moreau F. 1954 [‟1953”]. Les Champignons. Physiologie,
morphologie, développment et systématique. Vol. 2.
Paris: Lechevalier. 1179 p.
Morton JB, Benny GL. 1990. Revised classification of arbuscu-
lar mycorrhizal fungi (Zygomycetes): a new order,
Glomales, two new suborders, Glomineae and Gigaspor-
ineae, and two new families, Acaulosporaceae and
Gigasporaceae, with an emendation of Glomacae. Myco-
taxon 37:471–491.
Nadimi M, Beaudet D, Forget L, Hijri M, Lang BF. 2012.
Group I intron-mediated trans-splicing in mitochondria
of Gigaspora rosea and a robust phylogenetic affiliation of
arbuscular mycorrhizal fungi in Mortierellales. Mol Biol
Evol 29:2199–2012, doi:10.1093/molbev/mss088
Nagy LG, Ohm RA, Kovács GM, Floudas D, Riley R, Gácser A,
Sipiczki M, Davis JM, Doty SL, de Hoog GS, Lang BF,
Spatafora JW, Martin FM, Grigoriev IV, Hibbett DS.
2014. Latent homology and convergent regulatory evo-
lution underlies the repeated emergence of yeasts. Nat
Commun 5:4471, doi:10.1038/ncomms5471
———, Petkovits T, Kovács GM, Voigt K, Vágvölgyi C, Papp
T. 2011. Where is the unseen fungal diversity hidden?
A study of Mortierella reveals a large contribution of ref-
erence collections to the identification of fungal envi-
ronmental sequences. New Phytol 191:789–794, doi:
10.1111/j.1469-8137.2011.03707.x
Notredame C, Higgins DG, Heringa J. 2000. T-Coffee: a nov-
el method for fast and accurate multiple sequence align-
ment. J Molec Biol 302:205–217, doi:10.1006/jmbi.
2000.4042
Papanikolaou S, Panayotou MG. 2007. Lipid production by
oleaginous Mucorales cultivated on renewable carbon
sources. Eur J Lipid Sci Tech 109:1060–1070, doi:10.
1002/ejlt.200700169
Pelin A, Pombert JF, Salvioli A, Bonen L, Bonfante P, Corradi
N. 2012. The mitochondrial genome of the arbuscular
mycorrhizal fungus Gigaspora margarita reveals two unsus-
pected trans-splicing events of group I introns. New Phy-
tol 194:836–845, doi:10.1111/j.1469-8137.2012.04072.x
Redecker D, Schüßler A. 2014. Glomeromycota. In:
McLaughlin DJ, Spatafora JW, eds. Mycota VII. Part A.
Systematics and Evolution. New York: Springer-Verlag.
p 251–269.
Riley R, Charron P, Idnurm A, Farinelli L, Dalpé Y, Martin F,
Corradi N. 2013. Extreme diversification of the mating
type -high-mobility group (MATA-HMG) gene family
in a plant-associated arbuscular mycorrhizal fungus.
New Phytol 201:254–268, doi:10.1111/nph.12462
Rinke C, Schwientek P, Sczyrba A, Ivanova NN, Anderson IJ,
Cheng JF, Darling A, Malfatti S, Swan BK, Gies EA, Dods-
worth JA, Hedlund BP, Tsiamis G, Sievert SM, Liu WT,
Eisen JA, Hallam SJ, Kyrpides NC, Stepanauskas R,
Rubin EM, Hugenholtz P, Woyke T. 2013. Insights into
the phylogeny and coding potential of microbial dark
matter. Nature 499:431–437, doi:10.1038/nature12352
Roberson RW, Saucedo E, Maclean D, Propster J, Unger B,
Oneil TA, Parvanehgohar K, Cavanaugh C, Lowry D.
2011. The hyphal tip structure of Basidiobolus sp.: a zygo-
mycete fungus of uncertain phylogeny. Fungal Biol
115:485–492, doi:10.1016/j.funbio.2011.02.012
Ropars J, Toro KS, Noel J, Pelin A, Charron P, Farinelli L,
Marton T, Krüger, Fuchs J, Brachmann A, Corradi N.
2016. Evidence for the sexual origin of heterokaryosis
in arbuscular mycorrhizal fungi. Nat Microbiol 1: art.
no.16033.
Saikawa M. 1989. Ultrastructure of the septum in Ballocephala
verrucospora (Entomophthorales, Zygomycetes). Can J
Bot 67:2484–2488, doi:10.1139/b89-318
Salichos L, Stamatakis A, Rokas A. 2014. Novel information
theory-based measures for quantifying incongruence
among phylogenetic trees. Mol Biol Evol 31:1261–1271,
doi:10.1093/molbev/msu061
Sato Y, Narisawa K, Tsuruta K, Umezu M. 2010. Detection of
Betaproteobacteria inside the mycelium of the fungus
Mortierella elongata. Microbes Environ 25:321–324, doi:
10.1264/jsme2.ME10134
Schüßler A, Schwarzott D, Walker C. 2001. A new fungal
phylum, the Glomeromycota: phylogeny and evolu‐
tion. Mycol Res 105:1413–1421, doi:10.1017/
S0953756201005196
Sekimoto S, Rochon D, Long JE, Dee JM, Berbee ML. 2011. A
multigene phylogeny of Olpidium and its implications for
early fungal evolution. BMC Evol Biol 11:331, doi:
10.1186/1471-2148-11-331
Selosse MA, Le Tacon F. 1998. The land flora: a phototroph-
fungus partnership? Trends Ecol Evol 13:15–20, doi:
10.1016/S0169-5347(97)01230-5
Shakya M, Gottel N, Castro H, Yang ZK, Gunter L, Labbà J,
Muchero W, Bonito G, Vilgalys R, Tuskan G, Podar M,
Schadt CW. 2013. A multifactor analysis of fungal and
bacterial community structure in the root microbiome
of mature Populus deltoides trees. PLoS One 8:e76382,
doi:10.1371/journal.pone.0076382
Smith ME, Gryganskyi A, Bonito G, Nouhra E. 2013. Phyloge-
netic analysis of the genus Modicella reveals an indepen-
dent evolutionary origin of sporocarp-forming fungi in
1044 MYCOLOGIA
the Mortierellales. Fungal Genet Biol 61:61–68, doi:
10.1016/j.fgb.2013.10.001
Stajich JE, Berbee ML, Blackwell M, Hibbett DS, James TY,
Spatafora JW, Taylor JW. 2009. The fungi. Curr Biol
19:R840–R845, doi:10.1016/j.cub.2009.07.004
———, Wilke SK, Ahrén D, Au CH, Birren BW, Borodovsky
M, Burns C, Canbäck B, Casselton LA, Cheng CK,
Deng J, Dietrich FS, Fargo DC, Farman ML, Gathman
AC, Goldberg J, Guigó R, Hoegger PJ, Hooker JB, Hug-
gins A, James TY, Kamada T, Kilaru S, Kodira C, Kües U,
Kupfer D, Kwan HS, Lomsadze A, Li W, Lilly WW, Ma LJ,
Mackey AJ, Manning G, Martin F, Muraguchi H, Natvig
DO, Palmerini H, Ramesh MA, Rehmeyer CJ, Roe BA,
Shenoy N, Stanke M, Ter-Hovhannisyan V, Tunlid A,
Velagapudi R, Vision TJ, Zeng Q, Zolan ME, Pukkila
PJ. 2010. Insights into evolution of multicellular fun‐
gi from the assembled chromosomes of the mush‐
room Coprinopsis cinerea (Coprinus cinereus). Proc Natl
Acad Sci USA 107:11889–11894, doi:10.1073/pnas.
1003391107
Stamatakis A. 2006. RAxML-VI-HPC: maximum likelihood-
based phylogenetic analyses with thousands of taxa and
mixed models. Bioinformatics 22:2688–2690, doi:10.
1093/bioinformatics/btl446
Strullu-Derrien C, Kenrick P, Pressel S, Duckett JG, Rioult
J-P, Strullu D-G. 2014. Fungal associations in Horneophy-
ton ligneri from the Rhynie Chert (c. 407 million year
old) closely resemble those in extant lower land plants:
novel insights into ancestral plant-fungus symbioses.
New Phytol 203:964–979, doi:10.1111/nph.12805
Suga H, Chen Z, de Mendoza A, Sebé-Pedrós A, Brown MW,
Kramer E, Carr M, Kerner P, Vervoort M, Sánchez-Pons
N, Torruella G, Derelle R, Manning G, Lang BF, Russ C,
Haas BJ, Roger AJ, Nusbaum C, Ruiz-Trillo I. 2013. The
Capsaspora genome reveals a complex unicellular prehis-
tory of animals. Nat Comm 4:2325, doi:10.1038/
ncomms3325
Summerbell RC. 2005. Root endophyte and mycorrhizo-
sphere fungi of black spruce. Stud Mycol 53:121–145,
doi:10.3114/sim.53.1.121
Taylor TN, Hass H, Kerp H, Krings M, Hanlin RT. 2005. Peri-
thecial ascomycetes from the 400 million year old Rhy-
nie chert: an example of ancestral polymorphism.
Mycologia 97:269–285, doi:10.3852/mycologia.97.1.269
———, Krings M, Taylor E. 2014. Fossil Fungi. Amsterdam:
Academic Press, Elsevier. 382 p.
———, Remy W, Hass H, Kerp H. 1995. Fossil arbuscular
mycorrhizae from the Early Devonian. Mycologia
87:560–573, doi:10.2307/3760776
Tedersoo L, Smith ME. 2013. Lineages of ectomycorrhizal
fungi revisited: foraging strategies and novel lineages
revealed by sequences from belowground. Fungal Biol
Rev 27:83–99, doi:10.1016/j.fbr.2013.09.001
Terhonen E, Keriö S, Sun H, Asiegbu FO. 2014. Endophytic
fungi of Norway spruce roots in boreal pristine mire,
drained peatland and mineral soil and their inhibitory
effect on Heterobasidion parviporum in vitro. Fungal Ecol
9:17–26, doi:10.1016/j.funeco.2014.01.003
Than C, Ruths D, Nakhleh L. 2008. PhyloNet: a software
package for analyzing and reconstructing reticulate
evolutionary relationships. BMC Bioinformatics 9:322,
doi:10.1186/1471-2105-9-322
Tisserant E, Malbreil M, Kuo A, Kohler A, Symeonidi A,
Balestrini R, Charron P, Duensing N, Frei dit Frey N,
Gianinazzi-Pearson V, Gilbert LB, Handa Y, Herr JR,
Hijri M, Koul R, Kawaguchi M, Krajinski F, Lammers
PJ, Masclaux FG, Murat C, Morin E, Ndikumana S, Pagni
M, Petitpierre D, Requena N, Rosikiewicz P, Riley R,
Saito K, San Clemente H, Shapiro H, van Tuinen D,
Bécard G, Bonfante P, Paszkowski U, Shachar-Hill YY,
Tuskan GA, Young JP, Sanders IR, Henrissat B, Rensing
SA, Grigoriev IV, Corradi N, Roux C, Martin F. 2013.
Genome of an arbuscular mycorrhizal fungus provides
insight into the oldest plant symbiosis. Proc Natl Acad Sci
USA 110:20117–20122, doi:10.1073/pnas.1313452110
Torres-Cortés G, Ghignone S. 2015. Mosaic genome of endo-
bacteria in arbuscular mycorrhizal fungi: transkingdom
gene transfer in an ancient mycoplasma-fungus associa-
tion. Proc Natl Acad Sci USA 112:7785–7790, doi:
10.1073/pnas.1501540112
Tretter ED, Johnson EM, Benny GL, Lichtwardt RW, Wang Y,
Kandel P, Novak SJ, Smith JF, White MM. 2014. An
eight-gene molecular phylogeny of the Kickxellomyco-
tina, including the first phylogenetic placement of Asel-
lariales. Mycologia 106:912–935, doi:10.3852/13-253
Wagner L, Stielow B, Hoffmann K. 2013. A comprehensive
molecular phylogeny of the Mortierellales (Mortierello-
mycotina) based on nuclear ribosomal DNA. Persoonia
30:77–93, doi:10.3767/003158513X666268
Wang D, Wu R, Xu Y, Li M. 2013. Draft genome sequence of
Rhizopus chinensis CCTCCM201021, used for brewing tra-
ditional Chinese alcoholic beverages. Genome Announc
1:e0019512, doi:10.1128/genomeA.00195-12
Wang L, Chen W, Feng Y, Ren Y, Gu Z, Chen H, Wang H,
Thomas MJ, Zhang B, Berquin IM, Li Y, Wu J, Zhang
H, Song Y, Liu X, Norris JS, Wang S, Du P, Shen J,
Wang N, Yang Y, Wang W, Feng L, Ratledge C, Zhang
H, Chen YQ. 2011. Genome characterization of the ole-
aginous fungus Mortierella alpina. PLoS One 6:e28319,
doi:10.1371/journal.pone.0028319
White MM, James TY, O’Donnell K, Cafaro MJ, Tanabe Y,
Sugiyama J. 2006. Phylogeny of the Zygomycota based
on nuclear ribosomal sequence data. Mycologia 98:
872–884, doi:10.3852/mycologia.98.6.872
Wiens JJ, Morrill MC. 2011. Missing data in phylogenetic
analysis: reconciling results from simulations and empir-
ical data. Syst Biol 60:719–731, doi:10.1093/sysbio/
syr025
Wood V, Gwilliam R, Rajandream MA, Lyne M, Lyne R, Stew-
art A, Sgouros J, Peat N, Hayles J, Baker S, Basham D,
Bowman S, Brooks K, Brown D, Brown S, Chillingworth
T, Churcher C, Collins M, Connor R, Cronin A, Davis P,
Feltwell T, Fraser A, Gentles S, Goble A, Hamlin N, Har-
ris D, Hidalgo J, Hodgson G, Holroyd S, Hornsby T,
Howarth S, Huckle EJ, Hunt S, Jagels K, James K, Jones
L, Jones M, Leather S, McDonald S, McLean J, Mooney
P, Moule S, Mungall K, Murphy L, Niblett D, Odell C,
Oliver K, O’Neil S, Pearson D, Quail MA, Rabbinowitsch
E, Rutherford K, Rutter S, Saunders D, Seeger K, Sharp
S, Skelton J, Simmonds M, Squares R, Squares S, Stevens
SPATAFORA ET AL.: CLASSIFICATION OF THE ZYGOMYCETES 1045
K, Taylor K, Taylor RG, Tivey A, Walsh S, Warren T,
Whitehead S, Woodward J, Volckaert G, Aert R, Robben
J, Grymonprez B, Weltjens I, Vanstreels E, Rieger M,
Schäfer M, Müller-Auer S, Gabel C, Fuchs M, Düsterhöft
A, Fritzc C, Holzer E, Moestl D, Hilbert H, Borzym K,
Langer I, Beck A, Lehrach H, Reinhardt R, Pohl TM,
Eger P, Zimmermann W, Wedler H, Wambutt R, Pur-
nelle B, Goffeau A, Cadieu E, Dréano S, Gloux S,
Lelaure V, Mottier S, Galibert F, Aves SJ, Xiang Z,
Hunt C, Moore K, Hurst SM, Lucas M, Rochet M,
Gaillardin C, Tallada VA, Garzon A, Thode G, Daga RR,
Cruzado L, Jimenez J, Sánchez M, del Rey F, Benito J,
Domínguez A, Revuelta JL, Moreno S, Armstrong J,
Forsburg SL, Cerutti L, Lowe T, McCombie WR,
Paulsen I, Potashkin J, Shpakovski GV, Ussery D,
Barrell BG, Nurse P. 2002. The genome sequence of
Schizosaccharomyces pombe. Nature 415:871–880, doi:10.
1038/nature724
Yang J, Wang L, Ji X, Feng Y, Li X, Zou C, Xu J, Ren Y, Mi Q,
Wu J, Liu S, Liu Y, Huang X, Wang H, Niu X, Li J, Liang
L, Luo Y, Ji K, Zhou W, Yu Z, Li G, Liu Y, Li L, Qiao M,
Feng L, Zhang KQ. 2011. Genomic and proteomic anal-
yses of the fungus Arthrobotrys oligospora provide insights
into nematode-trap formation. PLoS Pathog 7:
e1002179, doi:10.1371/journal.ppat.1002179
Youssef NH, Couger MB, Struchtemeyer CG, Liggenstoffer
AS, Prade RA, Najar FZ, Atiyeh HK, Wilkins MR,
Elshahed MS. 2013. The genome of the anaerobic
fungus Orpinomyces sp. strain C1A reveals the unique
evolutionary history of a remarkable plant biomass
degrader. Appl Environ Microbiol 79:4620–4634, doi:
10.1128/AEM.00821-13
1046 MYCOLOGIA
