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Andre Gilles - One of the best experts on this subject based on the ideXlab platform.

  • microbiota associated with the skin gills and gut of the fish parachondrostoma Toxostoma from the rhone basin
    Freshwater Biology, 2020
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Andre Gilles
    Abstract:

    The close relationships between hosts and their microbiota underlie the current concept of holobionts. This biological entity enlarges our perception of the genomic diversity supported by individuals/species and the potential abilities of hosts to respond to the environment. We investigated a total of 54 specimens of the sofie fish Parachrondrostoma Toxostoma (Pt) for the taxonomic and functional composition of microbiota associated with the skin, gills, and gut tissues. Five wild populations from the Ardeche and Durance river basins in the Mediterranean part of the large catchment of the Rhone (southern France) were compared. We found that the skin microbiota was more diverse and variable in bacterial community composition than the gut microbiota. These differences suggest that different deterministic factors underlie the composition of these bacterial communities, resulting in tissue‐specific variation of the microbiota composition between wild fish populations inhabiting two rivers. Microbiota diversity and composition differed between wild Pt populations at both regional and local spatial scales. Using the Picrust tool, the taxonomic variation of the microbiota composition in the river fish populations could be associated with the enrichment of predicted metabolic pathways. In particular, carbohydrate metabolism was more represented and xenobiotic biodegradation pathways less represented in the gut microbiota of Pt populations from the Ardeche than of those from the Durance. This result suggests variability in the ability to acclimate to environmental features through the assimilation of food resources from plants and the detoxification of xenobiotic components. This study opens perspectives in the detection of subtle shifts in environmental features through the description of the microbiota composition, and in the potential prediction of the functional capacities of species to acclimate.

  • Canals as ecological corridors and hybridization zones for two cyprinid species
    Hydrobiologia, 2019
    Co-Authors: Emmanuel Guivier, Nicolas Pech, Andre Gilles, Nicolas Duflot, Laurence Tissot, Remi Chappaz
    Abstract:

    Predicted increases in the human population, in a context of climatic change and limiting freshwater resources, have raised awareness of the need to preserve aquatic ecosystems, their functions, and the biodiversity they harbor. The ecological reconciliation approach proposes the long-term co-existence of biodiversity preservation and the development of human activities. We investigated the ecological and evolutionary contributions of irrigation and hydroelectric canals in the highly fragmented and regulated Durance River (Rhône basin, Southern France), to the genetic diversity patterns of two interbreeding cyprinid species, the native Parachondrostoma Toxostoma, and the introduced Chondrostoma nasus species. We observed a high degree of genetic homogeneity along the length of the river. The maintenance of gene flow despite the presence of dams, and the detection of admixed populations and hybridization events in canals suggest that these canals may act as ecological corridors and hybrid zones with the potential to influence genetic resources for the native and introduced species. These anthropogenic structures vary considerably in terms of their spatial organization, size, and overall management, increasing habitat diversity in the urbanized section of river. Together with the restoration of natural habitats, canals can be considered as important structures for biodiversity dynamic in such urban conditions.

  • Microbiota Diversity Within and Between the Tissues of Two Wild Interbreeding Species
    Microbial Ecology, 2018
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Jeanfrancois Martin, Arnaud Ungaro, Andre Gilles
    Abstract:

    Understanding the role of microbiota as reproductive barriers or sources of adaptive novelty in the fundamental biological phenomenon of speciation is an exciting new challenge necessitating exploration of microbiota variation in wild interbreeding species. We focused on two interbreeding cyp-rinid species, Chondrostoma nasus and Parachondrostoma Toxostoma, which have geographic distributions characterized by a mosaic of hybrid zones. We described microbiota diversity and composition in the three main teleost mucosal tissues, the skin, gills and gut, in the parental parapatric populations. We found that tissue type was the principal determinant of bacterial community composition. In particular, there was strong microbiota differentiation between external and internal tissues, with secondary discrimination between the two species. These findings suggest that specific environmental and genetic filters associated with each species have shaped the bacterial communities, potentially reflecting deterministic assemblages of bacteria. We defined the core microbiota common to both Chondrostoma species for each tissue, highlighting the occurrence of microbe-host genome interactions at this critical level for studies of the functional consequences of hybridization. Further investigations will explore to what extend these specific tissue-associated microbiota signatures could be profoundly altered in hybrids, with functional consequences for post-mating reproductive isolation in relation to environmental constraints.

  • genomic porosity between invasive chondrostoma nasus and endangered endemic parachondrostoma Toxostoma cyprinidae the evolution of mhc iib genes
    PLOS ONE, 2013
    Co-Authors: Andrea Vetesnikova Simkova, Kristina Civaňova, Lenka Gettova, Andre Gilles
    Abstract:

    Two cyprinid species, Parachondrostoma Toxostoma, an endemic threatened species, and Chondrostoma nasus, an invasive species, live in sympatry in southern France and form two sympatric zones where the presence of intergeneric hybrids is reported. To estimate the potential threat to endemic species linked to the introduction of invasive species, we focused on the DAB genes (functional MHC IIB genes) because of their adaptive significance and role in parasite resistance. More specifically, we investigated (1) the variability of MHC IIB genes, (2) the selection pattern shaping MHC polymorphism, and (3) the extent to which trans-species evolution and intergeneric hybridization affect MHC polymorphism. In sympatric areas, the native species has more diversified MHC IIB genes when compared to the invasive species, probably resulting from the different origins and dispersal of both species. A similar level of MHC polymorphism was found at population level in both species, suggesting similar mechanisms generating MHC diversity. In contrast, a higher number of DAB-like alleles per specimen were found in invasive species. Invasive species tended to express the alleles of two DAB lineages, whilst native species tended to express the alleles of only the DAB3 lineage. Hybrids have a pattern of MHC expression intermediate between both species. Whilst positive selection acting on peptide binding sites (PBS) was demonstrated in both species, a slightly higher number of positively selected sites were identified in C. nasus, which could result from parasite-mediated selection. Bayesian clustering analysis revealed a similar pattern of structuring for the genetic variation when using microsatellites or the MHC approach. We confirmed the importance of trans-species evolution for MHC polymorphism. In addition, we demonstrated bidirectional gene flow for MHC IIB genes in sympatric areas. The positive significant correlation between MHC and microsatellites suggests that demographic factors may contribute to MHC variation on a short time scale.

  • does invasive chondrostoma nasus shift the parasite community structure of endemic parachondrostoma Toxostoma in sympatric zones
    Parasites & Vectors, 2012
    Co-Authors: Andrea Vetesnikova Simkova, Remi Chappaz, Andre Gilles, Petra Navratilova, Martina Davidova, Marketa Ondrackova, Melthide Sinama, Caroline Costedoat
    Abstract:

    Background The composition of parasite communities in two cyprinid species in southern France – native and threatened Parachondrostoma Toxostoma and introduced Chondrostoma nasus – was investigated. In sympatry, these two species form two hybrid zones in the Durance and Ardeche Rivers. Due to their different feeding preference and habitat positions in allopatry, we supposed a difference in parasite communities between fish species. We expected more similar parasite communities in sympatric zones associated with habitat overlap (facilitating the transmission of ectoparasites) and similar feeding (more generalist behaviour when compared to allopatry, facilitating the transmission of endoparasites) in both fish species. Finally, we investigated whether P. Toxostoma x C. nasus hybrids are less parasitized then parental species.

Remi Chappaz - One of the best experts on this subject based on the ideXlab platform.

  • microbiota associated with the skin gills and gut of the fish parachondrostoma Toxostoma from the rhone basin
    Freshwater Biology, 2020
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Andre Gilles
    Abstract:

    The close relationships between hosts and their microbiota underlie the current concept of holobionts. This biological entity enlarges our perception of the genomic diversity supported by individuals/species and the potential abilities of hosts to respond to the environment. We investigated a total of 54 specimens of the sofie fish Parachrondrostoma Toxostoma (Pt) for the taxonomic and functional composition of microbiota associated with the skin, gills, and gut tissues. Five wild populations from the Ardeche and Durance river basins in the Mediterranean part of the large catchment of the Rhone (southern France) were compared. We found that the skin microbiota was more diverse and variable in bacterial community composition than the gut microbiota. These differences suggest that different deterministic factors underlie the composition of these bacterial communities, resulting in tissue‐specific variation of the microbiota composition between wild fish populations inhabiting two rivers. Microbiota diversity and composition differed between wild Pt populations at both regional and local spatial scales. Using the Picrust tool, the taxonomic variation of the microbiota composition in the river fish populations could be associated with the enrichment of predicted metabolic pathways. In particular, carbohydrate metabolism was more represented and xenobiotic biodegradation pathways less represented in the gut microbiota of Pt populations from the Ardeche than of those from the Durance. This result suggests variability in the ability to acclimate to environmental features through the assimilation of food resources from plants and the detoxification of xenobiotic components. This study opens perspectives in the detection of subtle shifts in environmental features through the description of the microbiota composition, and in the potential prediction of the functional capacities of species to acclimate.

  • Canals as ecological corridors and hybridization zones for two cyprinid species
    Hydrobiologia, 2019
    Co-Authors: Emmanuel Guivier, Nicolas Pech, Andre Gilles, Nicolas Duflot, Laurence Tissot, Remi Chappaz
    Abstract:

    Predicted increases in the human population, in a context of climatic change and limiting freshwater resources, have raised awareness of the need to preserve aquatic ecosystems, their functions, and the biodiversity they harbor. The ecological reconciliation approach proposes the long-term co-existence of biodiversity preservation and the development of human activities. We investigated the ecological and evolutionary contributions of irrigation and hydroelectric canals in the highly fragmented and regulated Durance River (Rhône basin, Southern France), to the genetic diversity patterns of two interbreeding cyprinid species, the native Parachondrostoma Toxostoma, and the introduced Chondrostoma nasus species. We observed a high degree of genetic homogeneity along the length of the river. The maintenance of gene flow despite the presence of dams, and the detection of admixed populations and hybridization events in canals suggest that these canals may act as ecological corridors and hybrid zones with the potential to influence genetic resources for the native and introduced species. These anthropogenic structures vary considerably in terms of their spatial organization, size, and overall management, increasing habitat diversity in the urbanized section of river. Together with the restoration of natural habitats, canals can be considered as important structures for biodiversity dynamic in such urban conditions.

  • Microbiota Diversity Within and Between the Tissues of Two Wild Interbreeding Species
    Microbial Ecology, 2018
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Jeanfrancois Martin, Arnaud Ungaro, Andre Gilles
    Abstract:

    Understanding the role of microbiota as reproductive barriers or sources of adaptive novelty in the fundamental biological phenomenon of speciation is an exciting new challenge necessitating exploration of microbiota variation in wild interbreeding species. We focused on two interbreeding cyp-rinid species, Chondrostoma nasus and Parachondrostoma Toxostoma, which have geographic distributions characterized by a mosaic of hybrid zones. We described microbiota diversity and composition in the three main teleost mucosal tissues, the skin, gills and gut, in the parental parapatric populations. We found that tissue type was the principal determinant of bacterial community composition. In particular, there was strong microbiota differentiation between external and internal tissues, with secondary discrimination between the two species. These findings suggest that specific environmental and genetic filters associated with each species have shaped the bacterial communities, potentially reflecting deterministic assemblages of bacteria. We defined the core microbiota common to both Chondrostoma species for each tissue, highlighting the occurrence of microbe-host genome interactions at this critical level for studies of the functional consequences of hybridization. Further investigations will explore to what extend these specific tissue-associated microbiota signatures could be profoundly altered in hybrids, with functional consequences for post-mating reproductive isolation in relation to environmental constraints.

  • does invasive chondrostoma nasus shift the parasite community structure of endemic parachondrostoma Toxostoma in sympatric zones
    Parasites & Vectors, 2012
    Co-Authors: Andrea Vetesnikova Simkova, Remi Chappaz, Andre Gilles, Petra Navratilova, Martina Davidova, Marketa Ondrackova, Melthide Sinama, Caroline Costedoat
    Abstract:

    Background The composition of parasite communities in two cyprinid species in southern France – native and threatened Parachondrostoma Toxostoma and introduced Chondrostoma nasus – was investigated. In sympatry, these two species form two hybrid zones in the Durance and Ardeche Rivers. Due to their different feeding preference and habitat positions in allopatry, we supposed a difference in parasite communities between fish species. We expected more similar parasite communities in sympatric zones associated with habitat overlap (facilitating the transmission of ectoparasites) and similar feeding (more generalist behaviour when compared to allopatry, facilitating the transmission of endoparasites) in both fish species. Finally, we investigated whether P. Toxostoma x C. nasus hybrids are less parasitized then parental species.

  • Plasticity of ontogenetic trajectories in cyprinids: a source of evolutionary novelties
    Biological Journal of The Linnean Society, 2012
    Co-Authors: Emmanuel Corse, Remi Chappaz, Caroline Costedoat, Nicolas Pech, Melthide Sinama, Gabriel Nève, Andre Gilles
    Abstract:

    Research in evolutionary developmental (evo-devo) biology is making an increasingly important contribution to our understanding of the molecular mechanisms underlying the establishment of complex morphological traits. Deciphering the ontogenetic trajectories leading to the differentiation of sister species (and the existence of hybrids) is a new challenge in our understanding of speciation processes. In the present study, we characterized the ontogenetic trajectory of lower lip morphology in two cyprinid species and their hybrids. Chondrostoma Toxostoma has an arched lower lip and a generalist diet. Chondrostoma nasus has a straight lower lip and a specialist diet. An analysis of 99 C. Toxostoma ,9 9C. nasus and 25 first-generation (F1) hybrid individuals demonstrated that the difference between arched and straight lip morphology was found to depend strongly on the height/width ratio of the lower lip. A comparison of the ontogenetic trajectories of these morphometric traits showed that the height of the lower lip was isometric to body length in both species, whereas developmental changes involving an acceleration and a hypermorphosis of the widening of the lower lip led to a straight lip morphology in C. nasus. F1 hybrids were characterized by an extreme phenotype resulting from a rate of lower lip widening slower than that in the two parent species. Therefore, we rejected a codominance hypothesis and concluded that the first stage of hybridization provides the foundations of evolutionary novelty. These results have important evolutionary implications because lower lip shape is linked to dietary behaviour in many fish species. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 342‐355. ADDITIONAL KEYWORDS: Cyprinidae ‐ heterochrony ‐ hybridization ‐ hypermorphosis ‐ jaw shape ‐ Procrustes analysis.

Caroline Costedoat - One of the best experts on this subject based on the ideXlab platform.

  • does invasive chondrostoma nasus shift the parasite community structure of endemic parachondrostoma Toxostoma in sympatric zones
    Parasites & Vectors, 2012
    Co-Authors: Andrea Vetesnikova Simkova, Remi Chappaz, Andre Gilles, Petra Navratilova, Martina Davidova, Marketa Ondrackova, Melthide Sinama, Caroline Costedoat
    Abstract:

    Background The composition of parasite communities in two cyprinid species in southern France – native and threatened Parachondrostoma Toxostoma and introduced Chondrostoma nasus – was investigated. In sympatry, these two species form two hybrid zones in the Durance and Ardeche Rivers. Due to their different feeding preference and habitat positions in allopatry, we supposed a difference in parasite communities between fish species. We expected more similar parasite communities in sympatric zones associated with habitat overlap (facilitating the transmission of ectoparasites) and similar feeding (more generalist behaviour when compared to allopatry, facilitating the transmission of endoparasites) in both fish species. Finally, we investigated whether P. Toxostoma x C. nasus hybrids are less parasitized then parental species.

  • variability structure and selection of mhciib genes inchondrostoma Toxostoma and chondrostoma nasus in hybrid zones
    2012
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andre Gilles, Andrea Vetesnikova Simkova, Jeanfrancois Martin
    Abstract:

    To characterise the overall genetic diversity, population structure and selection processes in cyprinid fish, MHC genes of IIB class have been analyzed. As the model organism in this study, two congeneric cyprinids, the introduced Chondrostoma nasus and native, protected and endemic C. Toxostoma that live in sympatry and form a hybrid zone in the Durance River (South France, Mediterranean Sea drainage) were studied. For the individual determination (pure species versus hybrid) all fish were genotyped for mtDNA (cyt b) and 41 microsatellite loci. The allelic variability in exon 2 of two MHCIIB genes (DAB1-like and DAB3-like) representing the most variable region with the nonsynonymous sites specifying the peptide binding region was analysed. The results reveal the non uniform allele expression within individuals, duplication of both studied loci (previously showed in several cyprinid species) and that the exon 2 of DAB genes is subjected to positive selection. The difference in the MHCIIB profiles was found between allopatric and sympatric populations. Based on the hypothesis of parasite-mediated selection maintaining MHC polymorphism it could suggest the difference in parasite load between chondrostomes living in allopatric area and those living in hybrid zone.

  • Plasticity of ontogenetic trajectories in cyprinids: a source of evolutionary novelties
    Biological Journal of The Linnean Society, 2012
    Co-Authors: Emmanuel Corse, Remi Chappaz, Caroline Costedoat, Nicolas Pech, Melthide Sinama, Gabriel Nève, Andre Gilles
    Abstract:

    Research in evolutionary developmental (evo-devo) biology is making an increasingly important contribution to our understanding of the molecular mechanisms underlying the establishment of complex morphological traits. Deciphering the ontogenetic trajectories leading to the differentiation of sister species (and the existence of hybrids) is a new challenge in our understanding of speciation processes. In the present study, we characterized the ontogenetic trajectory of lower lip morphology in two cyprinid species and their hybrids. Chondrostoma Toxostoma has an arched lower lip and a generalist diet. Chondrostoma nasus has a straight lower lip and a specialist diet. An analysis of 99 C. Toxostoma ,9 9C. nasus and 25 first-generation (F1) hybrid individuals demonstrated that the difference between arched and straight lip morphology was found to depend strongly on the height/width ratio of the lower lip. A comparison of the ontogenetic trajectories of these morphometric traits showed that the height of the lower lip was isometric to body length in both species, whereas developmental changes involving an acceleration and a hypermorphosis of the widening of the lower lip led to a straight lip morphology in C. nasus. F1 hybrids were characterized by an extreme phenotype resulting from a rate of lower lip widening slower than that in the two parent species. Therefore, we rejected a codominance hypothesis and concluded that the first stage of hybridization provides the foundations of evolutionary novelty. These results have important evolutionary implications because lower lip shape is linked to dietary behaviour in many fish species. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 342‐355. ADDITIONAL KEYWORDS: Cyprinidae ‐ heterochrony ‐ hybridization ‐ hypermorphosis ‐ jaw shape ‐ Procrustes analysis.

  • The variability of MHC IIB class genes in two congeneric cyprinids and its influence on the composition of metazoan parasite communities
    2012
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andrea Vetesnikova Simkova, Andre Gilles
    Abstract:

    Our studies in family Cyprinidae are aimed to analyze life processes and the genetic diversity of fish populations. The potential influence on level of perception to parasite infections in relation with diversity and evolution of hosts MHC genes is also tested. The aims of this study were to investigate the composition of metazoan parasite communities in two pure species (the introduced Chondrostoma nasus and native, protected and endemic Parachondrostoma Toxostoma) and their respective hybrids. Based on the hypothesis of parasite-mediated selection maintaining MHC polymorphism it could suggest the difference in parasite load between chondrostomes living in allopatric area and those living in hybrid zone. A total of 7 Monogenea, 8 Trematoda, 3 Crustacea, 1 Acantohocephala species and larval stages of Mollusca were determined on Chondrostoma investigated. Monogenea and Trematoda were the most abundant parasite group. Among them, Dactylogyrus and was the most abundant parasite genus. When comparing two allopatric localities, low similarity in the presence of parasite species was observed. Higher similarity in parasite species richness was observed between sympatric localities.

  • the variability of mhc genes and parasite diversity in two cyprinid species c Toxostoma and c nasus in hybrid zone
    2011
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andre Gilles, Petra Navratilova, Andrea Vetesnikova Simkova
    Abstract:

    The aims of this study were to investigate the composition of metazoan parasite communities in two pure species, C. nasus and C. Toxostoma, and their respective hybrids. All individuals were genotyped for mtDNA (cyt b), 41 microsatellite loci and for DAB1 and DAB3 genes (MHC IIB class). Two allopatric and four sympatric populations were analyzed.

Nicolas Pech - One of the best experts on this subject based on the ideXlab platform.

  • microbiota associated with the skin gills and gut of the fish parachondrostoma Toxostoma from the rhone basin
    Freshwater Biology, 2020
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Andre Gilles
    Abstract:

    The close relationships between hosts and their microbiota underlie the current concept of holobionts. This biological entity enlarges our perception of the genomic diversity supported by individuals/species and the potential abilities of hosts to respond to the environment. We investigated a total of 54 specimens of the sofie fish Parachrondrostoma Toxostoma (Pt) for the taxonomic and functional composition of microbiota associated with the skin, gills, and gut tissues. Five wild populations from the Ardeche and Durance river basins in the Mediterranean part of the large catchment of the Rhone (southern France) were compared. We found that the skin microbiota was more diverse and variable in bacterial community composition than the gut microbiota. These differences suggest that different deterministic factors underlie the composition of these bacterial communities, resulting in tissue‐specific variation of the microbiota composition between wild fish populations inhabiting two rivers. Microbiota diversity and composition differed between wild Pt populations at both regional and local spatial scales. Using the Picrust tool, the taxonomic variation of the microbiota composition in the river fish populations could be associated with the enrichment of predicted metabolic pathways. In particular, carbohydrate metabolism was more represented and xenobiotic biodegradation pathways less represented in the gut microbiota of Pt populations from the Ardeche than of those from the Durance. This result suggests variability in the ability to acclimate to environmental features through the assimilation of food resources from plants and the detoxification of xenobiotic components. This study opens perspectives in the detection of subtle shifts in environmental features through the description of the microbiota composition, and in the potential prediction of the functional capacities of species to acclimate.

  • Canals as ecological corridors and hybridization zones for two cyprinid species
    Hydrobiologia, 2019
    Co-Authors: Emmanuel Guivier, Nicolas Pech, Andre Gilles, Nicolas Duflot, Laurence Tissot, Remi Chappaz
    Abstract:

    Predicted increases in the human population, in a context of climatic change and limiting freshwater resources, have raised awareness of the need to preserve aquatic ecosystems, their functions, and the biodiversity they harbor. The ecological reconciliation approach proposes the long-term co-existence of biodiversity preservation and the development of human activities. We investigated the ecological and evolutionary contributions of irrigation and hydroelectric canals in the highly fragmented and regulated Durance River (Rhône basin, Southern France), to the genetic diversity patterns of two interbreeding cyprinid species, the native Parachondrostoma Toxostoma, and the introduced Chondrostoma nasus species. We observed a high degree of genetic homogeneity along the length of the river. The maintenance of gene flow despite the presence of dams, and the detection of admixed populations and hybridization events in canals suggest that these canals may act as ecological corridors and hybrid zones with the potential to influence genetic resources for the native and introduced species. These anthropogenic structures vary considerably in terms of their spatial organization, size, and overall management, increasing habitat diversity in the urbanized section of river. Together with the restoration of natural habitats, canals can be considered as important structures for biodiversity dynamic in such urban conditions.

  • Microbiota Diversity Within and Between the Tissues of Two Wild Interbreeding Species
    Microbial Ecology, 2018
    Co-Authors: Emmanuel Guivier, Remi Chappaz, Nicolas Pech, Jeanfrancois Martin, Arnaud Ungaro, Andre Gilles
    Abstract:

    Understanding the role of microbiota as reproductive barriers or sources of adaptive novelty in the fundamental biological phenomenon of speciation is an exciting new challenge necessitating exploration of microbiota variation in wild interbreeding species. We focused on two interbreeding cyp-rinid species, Chondrostoma nasus and Parachondrostoma Toxostoma, which have geographic distributions characterized by a mosaic of hybrid zones. We described microbiota diversity and composition in the three main teleost mucosal tissues, the skin, gills and gut, in the parental parapatric populations. We found that tissue type was the principal determinant of bacterial community composition. In particular, there was strong microbiota differentiation between external and internal tissues, with secondary discrimination between the two species. These findings suggest that specific environmental and genetic filters associated with each species have shaped the bacterial communities, potentially reflecting deterministic assemblages of bacteria. We defined the core microbiota common to both Chondrostoma species for each tissue, highlighting the occurrence of microbe-host genome interactions at this critical level for studies of the functional consequences of hybridization. Further investigations will explore to what extend these specific tissue-associated microbiota signatures could be profoundly altered in hybrids, with functional consequences for post-mating reproductive isolation in relation to environmental constraints.

  • Plasticity of ontogenetic trajectories in cyprinids: a source of evolutionary novelties
    Biological Journal of The Linnean Society, 2012
    Co-Authors: Emmanuel Corse, Remi Chappaz, Caroline Costedoat, Nicolas Pech, Melthide Sinama, Gabriel Nève, Andre Gilles
    Abstract:

    Research in evolutionary developmental (evo-devo) biology is making an increasingly important contribution to our understanding of the molecular mechanisms underlying the establishment of complex morphological traits. Deciphering the ontogenetic trajectories leading to the differentiation of sister species (and the existence of hybrids) is a new challenge in our understanding of speciation processes. In the present study, we characterized the ontogenetic trajectory of lower lip morphology in two cyprinid species and their hybrids. Chondrostoma Toxostoma has an arched lower lip and a generalist diet. Chondrostoma nasus has a straight lower lip and a specialist diet. An analysis of 99 C. Toxostoma ,9 9C. nasus and 25 first-generation (F1) hybrid individuals demonstrated that the difference between arched and straight lip morphology was found to depend strongly on the height/width ratio of the lower lip. A comparison of the ontogenetic trajectories of these morphometric traits showed that the height of the lower lip was isometric to body length in both species, whereas developmental changes involving an acceleration and a hypermorphosis of the widening of the lower lip led to a straight lip morphology in C. nasus. F1 hybrids were characterized by an extreme phenotype resulting from a rate of lower lip widening slower than that in the two parent species. Therefore, we rejected a codominance hypothesis and concluded that the first stage of hybridization provides the foundations of evolutionary novelty. These results have important evolutionary implications because lower lip shape is linked to dietary behaviour in many fish species. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 342‐355. ADDITIONAL KEYWORDS: Cyprinidae ‐ heterochrony ‐ hybridization ‐ hypermorphosis ‐ jaw shape ‐ Procrustes analysis.

  • a pcr based method for diet analysis in freshwater organisms using 18s rdna barcoding on faeces
    Molecular Ecology Resources, 2010
    Co-Authors: Emmanuel Corse, Remi Chappaz, Caroline Costedoat, Nicolas Pech, Jeanfrancois Martin, Andre Gilles
    Abstract:

    : The development of DNA barcoding from faeces represents a promising method for animal diet analysis. However, current studies mainly rely on prior knowledge of prey diversity for a specific predator rather than on a range of its potential prey species. Considering that the feeding behaviour of teleosts may evolve with their environment, it could prove difficult to establish an exhaustive listing of their prey. In this article, we extend the DNA barcoding approach to diet analysis to allow the inclusion of a wide taxonomic range of potential prey items. Thirty-four ecological clade-specific primer sets were designed to cover a large proportion of prey species found in European river ecosystems. Selected primers sets were tested on isolated animal, algal or plant tissues and thereafter on fish faeces using nested PCR to increase DNA detection sensitivity. The PCR products were sequenced and analysed to confirm the identity of the taxa and to validate the method. The methodology developed here was applied to a diet analysis of three freshwater cyprinid species that are assumed to have similar feeding behaviour [Chondrostoma Toxostoma Toxostoma (Vallot 1837), Chondrostoma nasus nasus (Linnaeus, 1758) and Barbus barbus, (Linneaus 1758)]. These three species were sampled in four different hydrographic basins. Principal Component Analysis based on prey proportions identified distinct perilithon grazer and benthophagous behaviours. Furthermore, our results were consistent with the available literature on feeding behaviour in these fish. The simplicity of the PCR-based method and its potential generalization to other freshwater organisms may open new perspectives in food web ecology.

Andrea Vetesnikova Simkova - One of the best experts on this subject based on the ideXlab platform.

  • genomic porosity between invasive chondrostoma nasus and endangered endemic parachondrostoma Toxostoma cyprinidae the evolution of mhc iib genes
    PLOS ONE, 2013
    Co-Authors: Andrea Vetesnikova Simkova, Kristina Civaňova, Lenka Gettova, Andre Gilles
    Abstract:

    Two cyprinid species, Parachondrostoma Toxostoma, an endemic threatened species, and Chondrostoma nasus, an invasive species, live in sympatry in southern France and form two sympatric zones where the presence of intergeneric hybrids is reported. To estimate the potential threat to endemic species linked to the introduction of invasive species, we focused on the DAB genes (functional MHC IIB genes) because of their adaptive significance and role in parasite resistance. More specifically, we investigated (1) the variability of MHC IIB genes, (2) the selection pattern shaping MHC polymorphism, and (3) the extent to which trans-species evolution and intergeneric hybridization affect MHC polymorphism. In sympatric areas, the native species has more diversified MHC IIB genes when compared to the invasive species, probably resulting from the different origins and dispersal of both species. A similar level of MHC polymorphism was found at population level in both species, suggesting similar mechanisms generating MHC diversity. In contrast, a higher number of DAB-like alleles per specimen were found in invasive species. Invasive species tended to express the alleles of two DAB lineages, whilst native species tended to express the alleles of only the DAB3 lineage. Hybrids have a pattern of MHC expression intermediate between both species. Whilst positive selection acting on peptide binding sites (PBS) was demonstrated in both species, a slightly higher number of positively selected sites were identified in C. nasus, which could result from parasite-mediated selection. Bayesian clustering analysis revealed a similar pattern of structuring for the genetic variation when using microsatellites or the MHC approach. We confirmed the importance of trans-species evolution for MHC polymorphism. In addition, we demonstrated bidirectional gene flow for MHC IIB genes in sympatric areas. The positive significant correlation between MHC and microsatellites suggests that demographic factors may contribute to MHC variation on a short time scale.

  • does invasive chondrostoma nasus shift the parasite community structure of endemic parachondrostoma Toxostoma in sympatric zones
    Parasites & Vectors, 2012
    Co-Authors: Andrea Vetesnikova Simkova, Remi Chappaz, Andre Gilles, Petra Navratilova, Martina Davidova, Marketa Ondrackova, Melthide Sinama, Caroline Costedoat
    Abstract:

    Background The composition of parasite communities in two cyprinid species in southern France – native and threatened Parachondrostoma Toxostoma and introduced Chondrostoma nasus – was investigated. In sympatry, these two species form two hybrid zones in the Durance and Ardeche Rivers. Due to their different feeding preference and habitat positions in allopatry, we supposed a difference in parasite communities between fish species. We expected more similar parasite communities in sympatric zones associated with habitat overlap (facilitating the transmission of ectoparasites) and similar feeding (more generalist behaviour when compared to allopatry, facilitating the transmission of endoparasites) in both fish species. Finally, we investigated whether P. Toxostoma x C. nasus hybrids are less parasitized then parental species.

  • variability structure and selection of mhciib genes inchondrostoma Toxostoma and chondrostoma nasus in hybrid zones
    2012
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andre Gilles, Andrea Vetesnikova Simkova, Jeanfrancois Martin
    Abstract:

    To characterise the overall genetic diversity, population structure and selection processes in cyprinid fish, MHC genes of IIB class have been analyzed. As the model organism in this study, two congeneric cyprinids, the introduced Chondrostoma nasus and native, protected and endemic C. Toxostoma that live in sympatry and form a hybrid zone in the Durance River (South France, Mediterranean Sea drainage) were studied. For the individual determination (pure species versus hybrid) all fish were genotyped for mtDNA (cyt b) and 41 microsatellite loci. The allelic variability in exon 2 of two MHCIIB genes (DAB1-like and DAB3-like) representing the most variable region with the nonsynonymous sites specifying the peptide binding region was analysed. The results reveal the non uniform allele expression within individuals, duplication of both studied loci (previously showed in several cyprinid species) and that the exon 2 of DAB genes is subjected to positive selection. The difference in the MHCIIB profiles was found between allopatric and sympatric populations. Based on the hypothesis of parasite-mediated selection maintaining MHC polymorphism it could suggest the difference in parasite load between chondrostomes living in allopatric area and those living in hybrid zone.

  • The variability of MHC IIB class genes in two congeneric cyprinids and its influence on the composition of metazoan parasite communities
    2012
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andrea Vetesnikova Simkova, Andre Gilles
    Abstract:

    Our studies in family Cyprinidae are aimed to analyze life processes and the genetic diversity of fish populations. The potential influence on level of perception to parasite infections in relation with diversity and evolution of hosts MHC genes is also tested. The aims of this study were to investigate the composition of metazoan parasite communities in two pure species (the introduced Chondrostoma nasus and native, protected and endemic Parachondrostoma Toxostoma) and their respective hybrids. Based on the hypothesis of parasite-mediated selection maintaining MHC polymorphism it could suggest the difference in parasite load between chondrostomes living in allopatric area and those living in hybrid zone. A total of 7 Monogenea, 8 Trematoda, 3 Crustacea, 1 Acantohocephala species and larval stages of Mollusca were determined on Chondrostoma investigated. Monogenea and Trematoda were the most abundant parasite group. Among them, Dactylogyrus and was the most abundant parasite genus. When comparing two allopatric localities, low similarity in the presence of parasite species was observed. Higher similarity in parasite species richness was observed between sympatric localities.

  • the variability of mhc genes and parasite diversity in two cyprinid species c Toxostoma and c nasus in hybrid zone
    2011
    Co-Authors: Kristina Civaňova, Caroline Costedoat, Andre Gilles, Petra Navratilova, Andrea Vetesnikova Simkova
    Abstract:

    The aims of this study were to investigate the composition of metazoan parasite communities in two pure species, C. nasus and C. Toxostoma, and their respective hybrids. All individuals were genotyped for mtDNA (cyt b), 41 microsatellite loci and for DAB1 and DAB3 genes (MHC IIB class). Two allopatric and four sympatric populations were analyzed.