Figs 44-45 - uploaded by Daniel Wujek
Content may be subject to copyright.
Diagrammatic two-dimensional representations of flagellar apparatus elements in Lagynion delicatulum zoospores. Not to scale. Fig. 44. Schematic showing the positions of roots R1, R2 and R4 with respect to basal bodies 1 and 2, and the paths of the roots and the secondary cytoskeletal microtubules (scm) in the cell. Viewed from the anterior end of the cell, down the long axis of basal body 2. Fig. 45. More detailed diagram of the basal body region, showing the relative positions of basal bodies 1 and 2 and their connection by the deltoid striated band (DSB), as well as the proximal ends of roots R1, R2 and R4 and the association of root R1 with secondary cytoskeletal microtubules (scm). Viewed from the right side of the cell.
Source publication
Lagynion delicatulum Skuja is a first record for New Zealand freshwaters. Individual vegetative cells in nature and culture were sessile, aflagellate, and surrounded by a hyaline lorica lacking mineral deposits. Cells were uninucleate, had one or two chloroplasts with girdle lamellae and ring nucleoids, several mitochondria, and two to four basal-b...
Context in source publication
Similar publications
Different bacterial strains can have different value as food for heterotrophic nanoflagellates (HNF), thus modulating HNF growth and community composition. We examined the influence of prey food quality using four Limnohabitans strains, one Polynucleobacter strain and one freshwater actinobacterial strain on growth (growth rate, length of lag phase...
Heterotrophic flagellates (HFs) are important members of the aquatic microbial food web. However, information on their spatial patterns in relation to eutrophication is limited. Here, we examined the composition and spatial distributions of HFs (<3 μm) in subtropical coastal waters of different trophic status by re-analyzing two previously publishe...
Photosynthetic picoeukaryotes (PPE) with a cell size less than 3 mm play a critical role in oceanic primary production. In recent years, the composition of marine picoeukaryote communities has been intensively investigated by molecular approaches, but their photosynthetic fraction remains poorly characterized. This is largely because the classical...
In this paper, we define the Mallomonas alata group and describe M. alpestrina sp. nov. from an oligotrophic high mountain glacial lake on the slopes of Haba Xue Shan (Haba Snow Mountain), China. The Mallomonas alata group is excluded from the M. pumilio group primarily based on the approximately triangular shape of the collar scales, the small hoo...
Five unusual chrysophyte species were discovered in dilute softwater lakes and streams in Ontario, Canada. Only one of these (Heimiochrysis actinotrichia Bourrelly) had been previously described and is known only from single locations in France and Sweden. Three of the Ontario
entities are described here as new species: Rhizochrysis splendida n. sp...
Citations
... While the addition of layers to the inner surface of loricae has been shown previously for example in the chlorarachniophyte species Lotharella vacuolata [37], L. globosa [38] and L. reticulosa [39], the growth of loricae has not. This expansion is unique for loricae, which are usually more or less opened to one side, retain a constant size after formation and are found in distantly related eukaryotic groups such as Dinobryon (Ochrophyta) [40], Strombomonas (Euglenophyta) [41] and choanoflagellates [42]). Whether loricae of G. wildpretii retain one or more ostiole(s) at all times is not known. ...
A new relative of the chrysophyte genus Chrysopodocystis was found in Tenerife and termed Guanchochroma wildpretii. This unicellular alga was most noticeably discernible from Chrysopodocystis socialis (the only species of this genus) by the presence of a cyst-like stage with a multilayered lorica, which also functions as a dispersal unit and shows secondary wall growth. Secondary expansion of loricae (cell casings not involved in cell division, usually with a more or less pronounced opening) has never been observed previously and marks a unique feature of the new taxon. Plastids are non-randomly distributed within cells of G. wildpretii. 18S rRNA gene analyses identified the two species as sister lineages and placed them in a monophyletic group with the Synchromophyceae, a heterokont algal (Ochrophyta) class characterized by the presence of chloroplast complexes. Yet, neither Chrysopodocystis nor Guanchochroma showed this feature in ultrastructure analyses. Additionally, their 18S rRNA genes possessed distinct inserts, the highest GC-content known for Ochrophyta and exceptionally long branches on the Ochrophyta 18S rDNA phylogenetic tree, suggesting substantially increased substitution rates along their branch compared to Synchromophyceae. Plastid marker data (rbcL) recovered a monophyletic clade of Chrysopodocystis, Guanchochroma and Synchromophyceae as well, yet with lower supports for internal split order due to limited resolution of the marker. Evidence for the sequence of events leading to the formation of the plastid complex of Synchromophyceae still remains ambiguous because of the apparently short timeframe in which they occurred.
... During an investigation of the chrysophyte alga La gynion delicatulum (O'Kelly and Wujek 2001) cells of the eustigmatophyte alga Pseudocharaciopsis minuta (Braun) Hibberd contaminating our culture were isolated and placed in culture. Of particular interest was the presence of orange-red deposits at the base of Pseudocharaci opsis minuta's stalk. ...
The stalks of the eustigmatophyte were examined by light and scanning electron microscopy. Light microscopy revealed orange-red granules at the base of the stalk. Energy dispersive X-ray microanalysis of the bases indicated that they were mainly composed of manganese. Manganese has not been previously reported from eustigmatophytes. This study indicates that the Eustigmatophyceae needs further study into many aspects of the biology.
Filaments of Oedocladium prescottii ISLAM, collected from China, are characterized by a series of caps which are attached to the wall of consecutive vegetative cells. The lateral displacement of the caps is determined by the structure of the top cell which has an asymmetric anterior weakening site. It is speculated that this structure is an adaptive mechanism for growth in soil. Examination of the vegetative cell structure and the mechanism of cell division in Oedocladium give additional insight in some aspects of branch development and tip growth.
Filaments of Oedocladium prescottii Islam, collected from China, are characterized by a series of caps which are attached to the wall of consecutive vegetative cells. The lateral displacement of the caps is determined by the structure of the top cell which has an asymmetric anterior weakening site. It is speculated that this structure is an adaptive mechanism for growth in soil. Examination of the vegetative cell structure and the mechanism of cell division in Oedocladium give additional insight in some aspects of branch development and tip growth.
Glossomastix chrysoplasta gen. et sp. nov. is described from cultures isolated from sandstone rubble, Sorrento Back Beach, Mornington Peninsula, Victoria, Australia. The alga forms wall-less, coccoidal vegetative cells that congregate in mucilaginous colonies and reproduce by successive bipartition. Plastids have girdle lamellae and partially embedded pyrenoids that are traversed by cytoplasmic channels. Zoospores are uniflagellate and swim poorly; a narrow lingulate pseudopod provides their primary form of motion. The single flagellum, which lacks hairs, a flagellar swelling, and autofluorescence, is the equivalent of the posterior flagellum in other golden algae. The anterior flagellum is absent; the basal body with which it would normally be associated is blind. The flagellar apparatus has two basal bodies, three microtubular roots, and a rhizoplast. The posterior (elder) basal body has a transitional helix that is proximal to the basal plate. Glossomastix chrysoplasta, placed in the Pinguiophyceae on the basis of molecular sequence and biochemical data, shares some ultrastructural features with other members of the class, especially Polypodochrysis teissieri, which has similar zoospores, but it also differs from other pinguiophytes in many respects. Glossomastix chrysoplasta is the pinguiophyte with, on average, the largest cells (exclusive of external materials), and it is the only one with a colonial habit.
