Biron G. David

Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023

During a survey done on the mineral springs in the French Massif Central region, a new Chamaepinnularia species (Bacillariophyceae) was found and is hereby described: Chamaepinnularia salina Beauger, C.E.Wetzel, Allain & Ector sp. nov. This new small species, with valves linear with almost parallel margins, is formally described using light and sca...

Diatoms colonised most aquatic ecosystems on earth from marine to freshwater ones, and also the springs containing a fairly large and poorly known diversity of diatoms. While investigations on the influence of substrates on diatom assemblages in rivers are relatively well documented, few studies have been done for mineral springs. The purpose of th...

Aphids are renowned plant parasites of agriculture, horticulture and forestry, causing direct physical damage by sucking phloem and especially by transmission of plant pathogenic viruses. The huge yield loss they cause amounts to hundreds of millions of dollars globally, and because of this damage and the intense efforts expended on control, some 2...

In a scenario of worldwide honey bee decline, assessing colony strength is becoming increasingly important for sustainable beekeeping. Temporal counts of number of comb cells with brood and food reserves offers researchers data for multiple applications, such as modelling colony dynamics, and beekeepers information on colony strength, an indicator...

Diatoms are good indicators of water quality because of their great diversity and wide ecological range. They are also interesting in assessing the impact of radioactivity on ecosystems because of their capacity to absorb radioelements. They also show radio-induced deformities, observed in many species. In order to assess more precisely the impact...

Aphids are renowned plant parasites of agriculture, horticulture and forestry, causing direct physical damage by sucking phloem and especially by transmission of plant pathogenic viruses. The huge yield loss they cause amounts to hundreds of millions of dollars globally, and because of this damage and the intense efforts expended on control, some 2...

Sociality has brought many advantages to various hymenoptera species, including their ability of regulating physical factors in their nest (e.g., temperature). Although less studied, humidity is known to be important for egg, larval and pupal development, and also for nectar concentration. Two subspecies of Apis mellifera of the M evolutionary line...

Cet ouvrage collectif, rédigé par des chercheuses et chercheurs du CNRS et de l’Inra ainsi que des universitaires, nous dévoile le monde fascinant des abeilles – ce qu’elles ont, ce qu’elles sont et ce qu’elles font –, décrypte les liens qu’elles entretiennent avec la nature et l’humanité, les dangers qui les guettent et qui nous menacent, tout en...

Over millennia, life has been exposed to ionizing radiation from cosmic rays and natural radioisotopes. Biological experiments in underground laboratories have recently demonstrated that the contemporary terrestrial radiation background impacts the physiology of living organisms, yet the evolutionary consequences of this biological stress have not...

Sociality has brought many advantages to various hymenoptera species, including their ability of regulating physical factors in their nest (e.g., temperature). Although less studied, humidity is known to be important for egg, larval and pupal development, and also for nectar concentration. Two subspecies of Apis mellifera of the M evolutionary line...

Linear equation, r and R2 for each model of the relationship between RH observed in the winter in the beehives (in-hive) with those recorded outside (external). The empty places correspond to iButtons that were absent from the beehive at this moment. Missing data are due to a breakdown for two iButtons for a couple of days. (XLSX)

Mean, median with 1st and 3rd quartiles, maximum and minimum values of RH levels for each season over a complete year (September 2015 –October 2016). For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated using only the external iButton. (XLSX)

Mean, median with 1st and 3rd quartiles, maximum and minimum values of RH levels over a complete year (September 2015 –October 2016) for each conservatory. For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated using only the external iButton. (XLSX)

Linear modeling of the relationship between RH observed in the winter in the beehives (in-hive) with those recorded in their habitat (external). The modeling was done for one day (December 11, 2015) and separated in two parts: downward RH from 6 a.m. to 5 p.m. and upward RH from 6 p.m. to 5 a.m. the next day. Linear modeling for A. m. mellifera is...

RH levels during spring 2016 for Pontaumur (A), Rochefort (B), Gimonde (C), and Zavial (D). Box plots: mean (orange point), median (black stripes) with 1st and 3rd quartiles, maximum and minimum values. For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated usi...

Linear equation, r and R2 for each model of the relationship between RH observed in the summer in the beehives (in-hive) with those recorded outside (external). The empty places correspond to iButtons that were absent from the beehive at this moment. Missing data are due to a breakdown for two iButtons for a couple of days. (XLSX)

Relative humidity (RH) measured by the external iButton in the four conservation centers: Pontaumur (▲), Rochefort (●), Zavial (♦) and Gimonde (■), (A) in summer (July 21, 2016) and (B) in winter (December 11, 2015). These two dates were chosen because they have the most similar external RH among the four conservatories in the two seasons, and beca...

RH regulations observed in winter for each colony (iButton B) regarding to the time of the day: From 6 a.m. to 5 p.m. the next morning. Green means the in-hive RH is lower than the external RH (negative regulation), red means the opposite (positive regulation). (TIF)

RH levels during autumn 2015 for Pontaumur (A), Rochefort (B), Gimonde (C), and Zavial (D). Box plots: mean (orange point), median (black stripes) with 1st and 3rd quartiles, maximum and minimum values. For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated usi...

RH levels during summer 2016 for Pontaumur (A), Rochefort (B), Gimonde (C), and Zavial (D). Box plots: mean (orange point), median (black stripes) with 1st and 3rd quartiles, maximum and minimum values. For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated usi...

Mandel’s graphs showing results of statistical analysis on homogeneity of means (A) and variances (B) of RH measured in hives of the four conservation centers for each iButton (A, B, C) during spring 2016. (TIF)

Mandel’s graphs showing results of statistical analysis on homogeneity of means (A) and variances (B) of RH measured in hives of the four conservation centers for each iButton (A, B, C) during summer 2016. (TIF)

RH levels during winter 2016 for Pontaumur (A), Rochefort (B), Gimonde (C), and Zavial (D). Box plots: mean (orange point), median (black stripes) with 1st and 3rd quartiles, maximum and minimum values. For each iButton (i.e. A, B, C) of conservation centers, in-hive RH data were calculated using the six beehives, and external RH was calculated usi...

Mandel’s graphs showing results of statistical analysis on homogeneity of means (A) and variances (B) of RH measured in hives of the four conservation centers for each iButton (A, B, C) during autumn 2015. (TIF)

Mandel’s graphs showing results of statistical analysis on homogeneity of means (A) and variances (B) of RH measured in hives of the four conservation centers for each iButton (A, B, C) during winter 2016. (TIF)

Sociality has brought many advantages to various hymenoptera species, including their ability of regulating physical factors in their nest (e.g., temperature). Although less studied, humidity is known to be important for egg, larval and pupal development. Two subspecies of Apis mellifera of the M branch, also called black bees, were used as models...

In Europe, several studies revealed that native populations of Apis mellifera are adapted to local climate and flora. However, so far, no study has been conducted on the Iberian honeybee, Apis mellifera iberiensis. Therefore, the aim of this study was to evaluate the existence of local adaptation in the Iberian honeybee. This study was divided into...

The honey bee is threatened by biological agents and pesticides that can act in combination to induce synergistic effects on its physiology and lifespan. The synergistic effects of a parasite/pesticide combination have been demonstrated on workers and queens, but no studies have been performed on drones despite their essential contribution to colon...

Biological experiments conducted in underground laboratories over the last decade have shown that life can respond to relatively small changes in the radiation background in unconventional ways. Rapid changes in cell growth, indicative of hormetic behaviour and long‐term inheritable changes in antioxidant regulation have been observed in response t...

The host–vector–pathogen interactions are governed since their origin by a subtle balance between attack and transmission strategies and defense mechanisms. Molecular dialogues are established between a pathogen and its host, these ones will generate a mutual selection pressure that will result in profound changes in expression of host and pathogen...

At very low radiation dose rates, the effects of energy depositions in cells by ionizing radiation is best understood stochastically, as ionizing particles deposit energy along tracks separated by distances often much larger than the size of cells. We present a thorough analysis of the stochastic impact of the natural radiative background on cells,...

Physiological changes associated with evolutionary and ecological processes such as diversification, range expansion or speciation are still incompletely understood, especially for non-model species. Here we study differences in protein expression in response to temperature in a western Mediterranean diving beetle species complex, using two-dimensi...

Fusarium graminearum (Fg) is the main causal agent of the Fusarium head blight disease (FHB) in a wide range of staple cereal crops. As a consequence of infection, severe yield and quality losses occur along with in planta mycotoxin (DON) production making grains incompatible with food uses. Our knowledge of the molecular and physiological plant re...

Recent surveys of microbiomes indicate that the communities of commensal and symbiotic micro-organisms living in guts are involved in maturation and functioning of animal nervous systems. Therefore, when a manipulative parasite colonizes a host tissue to ensure its growth and the completion of its life cycle, a plausible assumption is that the mole...

The mycotoxigenic fungal species Fusarium graminearum is able to attack several important cereal crops, such as wheat and barley. By causing Fusarium Head Blight (FHB) disease, F. graminearum induces yield and quality losses and poses a public health concern due to in planta mycotoxin production. The molecular and physiological plant responses to F...

Population proteomics has a great potential to address evolutionary and ecological questions, but its use in wild populations of non-model organisms is hampered by uncontrolled sources of variation. Here we compare the response to temperature extremes of two geographically distant populations of a diving beetle species (Agabus ramblae) using 2-D DI...

Microsporidian genomes are the leading models to understand the streamlining in response to a pathogenic lifestyle; they are gene-poor and often possess small genomes. In this study, we show a feature of microsporidian genomes that contrasts this pattern of genome reduction. Specifically, genome investigations targeted at Anncaliia algerae, a human...

Many invasive pathogens effectively bypass the insect defenses to ensure the completion of their life cycle. Among those, an invasive microsporidian species, Nosema ceranae, can cause nosemosis in honeybees. N. ceranae was first described in the Asian honeybee Apis cerana and is suspected to be involved in Western honeybee (Apis mellifera) declines...

Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how pa...

Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how pa...

Fusarium Head Blight (FHB) is one of the most devastating plant disease affecting wheat and other small grains, worldwide. FHB is caused primarily by the mycotoxigenic ascomycetous fungus Fusarium graminearum (Fg). The infection process not only alters the yield and quality of grains, but also poses a major public health concern due to the producti...

Modern agriculture often involves the use of pesticides to protect crops. These substances are harmful to target organisms (pests and pathogens). Nevertheless, they can also damage non-target animals, such as pollinators and entomophagous arthropods. It is obvious that the undesirable side effects of pesticides on the environment should be reduced...

Among the most damaging fungal pathogens of wheat,Fusarium graminearum, main causal agent of Fusarium head blight (FHB), reduces significantly yield worldwide, and affects grains quality by mycotoxins contamination. During the past years, numbers of FHB resistance QTL with moderate effects against this pathogen have been identified in very genetica...

Among the most damaging fungal pathogens of wheat, Fusarium graminearum, main causal agent of Fusarium head blight (FHB), reduces significantly yield worldwide, and affects grains quality by mycotoxins contamination. During the past years, numbers of FHB resistance QTL with moderate effects against this pathogen have been identified in very genetic...

Genetic diversity of a host species is a key factor to counter infection by parasites. Since two separation events and the beginning of beekeeping, the Western honeybee, Apis mellifera, has diverged in many phylogenetically-related taxa that share common traits but also show specific physiological, behavioural and morphological traits. In this stud...

Insect pest development is often linearly related to air temperature, without taking into account the multiple interactions between the particular host plant and pest, the microclimatic conditions actually experienced by the insect, and the non-linear response of insect development rate to temperature. In this study, using an integrative biophysica...

Many parasite taxa are able to alter a wide range of phenotypic traits of their hosts in ways that seem to improve the parasite's chance of completing its life cycle. Host behavioural alterations are classically seen as compelling illustrations of the 'extended phenotype' concept, which suggests that parasite genes have phenotype effects on the hos...

Vector-borne diseases (VBD) are defined as infectious diseases of humans and animals caused by pathogenic agents such as viruses, protists, bacteria, and helminths transmitted by the bite of blood-feeding arthropod (BFA) vectors. VBD represent a major public health threat in endemic areas, generally subtropical zones, and many are considered to be...

In ecosystems, a variety of biological, chemical and physical stressors may act in combination to induce illness in populations of living organisms. While recent surveys reported that parasite-insecticide interactions can synergistically and negatively affect honeybee survival, the importance of sequence in exposure to stressors has hardly received...

Supplementary Table S1

Plusieurs hypothèses cherchent à expliquer les bases adaptatives liées à l’émergence du mode de vie parasitaire de type endophyte dont l’avantage nutritionnel conféré par un développement directement au sein des tissus végétaux apparaît comme central. L’ensemble des éléments obtenus à ce jour semblent confirmer que les parasites endophytes optimise...

This chapter presents the interest of proteomics to survey host-pathogen interactions, a synthetic review of previous proteomics studies, the pitfalls of the current approach in surveys, new conceptual approaches to decipher host-parasite interactions, a new avenue to decipher the crosstalk diversity involved in trophic interactions in a habitat an...

Depuis près d'une décennie, les effectifs de pollinisateurs déclinent. Parmi les insectes chargés de cette tache, indispensable à notre agriculture, les abeilles semblent être les plus touchées. À l'heure où les ruches tremblent face à l'invasion du frelon asiatique, la véritable menace n'est pas celle que l'on croit.

Depuis près d’une décennie, les effectifs de pollinisateurs déclinent. Parmi les insectes chargés de cette tâche, indispensable à notre agriculture, les abeilles semblent être les plus touchées. À l’heure où les ruches tremblent face à l’invasion du frelon asiatique, la véritable menace n’est pas celle que l’on croit.

Background: The honeybee, Apis mellifera, is undergoing a worldwide decline whose origin is still in debate. Studies performed for twenty years suggest that this decline may involve both infectious diseases and exposure to pesticides. Joint action of pathogens and chemicals are known to threaten several organisms but the combined effects of these...

One of the most fascinating examples of parasite-induced host manipulation is that of hairworms, first, because they induce a spectacular "suicide" water-seeking behavior in their terrestrial insect hosts and, second, because the emergence of the parasite is not lethal per se for the host that can live several months following parasite release. The...

Microsporidia are fungi-related obligate intracellular parasites with a highly reduced and compact genome, as for Encephalitozoon species which harbor a genome smaller than 3 Mbp. Genome compaction is reflected by high gene density and, for larger microsporidian genomes, size variation is due to repeat elements that do not drastically affect gene d...

We performed a phylogenetic character mapping on 26 stocks of Trypanosoma cruzi, the parasite responsible for Chagas disease, and 2 stocks of the sister taxon T. cruzi marinkellei to test for possible associations between T. cruzi-subspecific phylogenetic diversity and levels of protein expression, as examined by proteomic analysis and mass spectro...

Mosquito-transmitted pathogens pass through the insect's midgut (MG) and salivary gland (SG). What occurs in these organs in response to a blood meal is poorly understood, but identifying the physiological differences between sugar-fed and blood-fed (BF) mosquitoes could shed light on factors important in pathogens transmission. We compared differe...

Human and animal African trypanosomoses, or sleeping sickness and Nagana, are neglected vector-borne parasitic diseases caused by protozoa belonging to the Trypanosoma genus. Advances in proteomics offer new tools to better understand host-vector-parasite crosstalks occurring during the complex parasitic developmental cycle, and to determine the ou...

The developmental rate of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is supposed to be directly proportional to air temperature between the lower and upper developmental thresholds. However, some review papers suggest that insect species have a higher developmental rate when reared in thermoperiodic conditions as compared with c...

Parasite-induced alteration of host behaviour is a widespread transmission strategy among pathogens. Understanding how it works is an exciting challenge from both a mechanistic and an evolutionary perspective. In this review, we use key examples to examine the proximate mechanisms by which parasites are known to control the behaviour of their hosts...

Three Nearctic and six Palearctic populations of Delia radicum L., two Palearctic populations of D. antiqua Meigen, and one Palearctic population of D. floralis Fallen were used to evaluate the range of intraspecific variation in the chorionic ultrastructures of the egg of D. radium, and to compare the chorionic ultrastructures of these eggs with t...

Many scientists working on pathogens (viruses, bacteria, fungi, parasites) are betting heavily on data generated by longitudinal genomic-transcriptomic-proteomic studies to explain biochemical host-vector-pathogen interactions and thus to contribute to disease control. Availability of genome sequences of various organisms, from viruses to complex m...

Parasite‐induced alteration of host behaviour is a widespread transmission strategy among pathogens. Understanding how it works is an exciting challenge from both a mechanistic and an evolutionary perspective. In this review, we use key examples to examine the proximate mechanisms by which parasites are known to control the behaviour of their hosts...

Parasite-induced alteration of host behaviour is a widespread transmission strategy among pathogens. Understanding how it works is an exciting challenge from both a mechanistic and an evolutionary perspective. In this review, we use key examples to examine the proximate mechanisms by which parasites are known to control the behaviour of their hosts...

There are many impressive examples of host manipulation by parasites, but mechanisms underlying these ethological changes, as well as their physiological consequences, are not well characterized. Here, we analyzed part of the cerebral proteome of brine shrimp Artemia infected by manipulative cestodes, using for the first time the ProteinChip Surfac...

We review the results of a series of experiments involving Aedes aegypti and its microsporidian parasite Vavraia culicis to illustrate how intra-specific competition and parasitism shape life history traits. More specifically these experiments showed that some major components of virulence are host condition-dependent in this system, while others a...

Human African trypanosomiasis is characterised by an important clinical diversity. Although Trypanosoma brucei gambiense field stocks isolated from patients in the same focus did not exhibit apparent genetic variability, they showed marked differences in terms of virulence (capacity to multiply inside a host) and pathogenicity (ability of producing...

Many scientists working on pathogens (viruses, bacteria, fungi, parasites) are betting heavily on data generated by longitudinal genomic–transcriptomic–proteomic studies to explain biochemical host–vector–pathogen interactions and thus to contribute to disease control. Availability of genome sequences of various organisms, from viruses to complex m...

Parasitic manipulations of host behaviour are known from a wide range of host-parasite associations. However, the understanding of these phenomena is far from complete and detailed investigation of their proximate causes is needed. Many studies report behavioural modifications, such as altered feeding rates in tsetse fly (Glossina) infected with th...

Despite increasing evidence of behavioural manipulation of their vectors by pathogens, the underlying mechanisms causing infected vectors to act in ways that benefit pathogen transmission remain enigmatic in most cases. Here, 2-D DIGE coupled with MS were employed to analyse and compare the head proteome of mosquitoes (Anopheles gambiae sensu stric...