References of "Michaux, Johan"
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See detailConsequence of past anthropogenic forest fragmentation on the genetic structure of European mammals: the example of the edible dormouse (Glis glis)
Michaux, Johan ULiege; Hurner, H.; Krystufek, B et al

in Biological Journal of the Linnean Society (in press)

The genetic structure of forest animal species may allow the spatial dynamics of the forests themselves to be tracked. Two scales of change are commonly discussed: changes in forest distribution during ... [more ▼]

The genetic structure of forest animal species may allow the spatial dynamics of the forests themselves to be tracked. Two scales of change are commonly discussed: changes in forest distribution during the Quaternary, due to glacial/ interglacial cycles, and current fragmentation related to habitat destruction. However, anthropogenic changes in forest distribution may have started well before the Quaternary, causing fragmentation at an intermediate time scale that is seldom considered. To explore the relative role of these processes, the genetic structure of a forest species with narrow ecological preferences, the edible dormouse (Glis glis), was investigated in a set of samples covering a large part of its Palaearctic distribution. Strong and complex geographical structure was revealed from the use of microsatellite markers. This structure suggests that fragmentation occurred in several steps, progressively splitting the ancestral population into peripheral isolated ones. The fact that this structure postdates post-glacial recolonization, together with dating based on microsatellite data, supports the hypothesis that the differentiation was recent, starting around 9000 years ago, and took place stepwise, possibly up to Medieval times. This complements a classic phylogeographical interpretation based on the effect of past climate change, and supports the role of anthropogenic deforestation as a trigger of recent intraspecific differentiation. [less ▲]

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See detailFatal infection by Versteria mustelae (Gmelin, 1790) in the critically endangered Mustela lutreola (Linnaeus, 1761) in Spain
Fournier-Chambrillon, Christine; Torres, Miquel; André, Adrien ULiege et al

in Parasitology Research (2018), 117(10),

The riparian European mink (Mustela lutreola), currently surviving in only three unconnected sites in Europe, is now listed as a critically endangered species in the IUCN Red List of Threatened Species ... [more ▼]

The riparian European mink (Mustela lutreola), currently surviving in only three unconnected sites in Europe, is now listed as a critically endangered species in the IUCN Red List of Threatened Species. Habitat loss and degradation, anthropogenic mortality, interaction with the feral American mink (Neovison vison), and infectious diseases are among the main causes of its decline. In the Spanish Foral Community of Navarra, where the highest density of M. lutreola in its western population has been detected, different studies and conservation measures are ongoing, including health studies on European mink, and invasive American mink control. We report here a case of severe parasitism with progressive physiological exhaustion in an aged free-ranging European mink female, which was accidentally captured and subsequently died in a live-trap targeting American mink. Checking of the small intestine revealed the presence of 17 entangled Versteria mustelae worms. To our knowledge, this is the first description of hyperinfestation by tapeworms in this species. [less ▲]

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See detailPathobiome of the Lyme disease principal reservoir in southern Quebec (Peromyscus leucopus)
Andre, Adrien; Mouton, alice; Millien, Virginie et al

Conference (2018)

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See detailWhy some species disappear and other expand? The example of the minks (M. lutreola and N. vison) and the European otter (Lutra lutra
Michaux, Johan ULiege

Conference (2018)

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. Some species have a strong reduction of their populations, following the ... [more ▼]

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. Some species have a strong reduction of their populations, following the fragmentation of their habitats, the competition with other species, different pollutions or the appearance of new diseases. In contrast, several other species tend to expand their distributions areas and can even be considered as invasive species in some cases. The aim of my presentation will be to better understand which biological factors, including genetics, could lead to decrease populations of a species until extinction or in contrast, to help a species to expand its population densities and its distribution area. These hypotheses will be illustrated by our recent genetic results obtained on the European mink (Mustela lutreola), the American mink (Neovison vison) and the European otter (Lutra lutra). [less ▲]

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See detailAquatic and terrestrial water voles: phylogeography and morphometrics
chevret, pascale; Helzaci, Zeycan; Quere, Jean Pierre et al

Conference (2018)

Water voles from the genus Arvicola display an amazing ecological versality, with aquatic and terrestrial populations. Their taxonomic status and evolutionary relationships has caused a long-standing ... [more ▼]

Water voles from the genus Arvicola display an amazing ecological versality, with aquatic and terrestrial populations. Their taxonomic status and evolutionary relationships has caused a long-standing dispute. Two aquatic (sapidus, amphibius) and one fossorial species (scherman) are currently described. We used mitochondrial cytochrome b (cytb) gene sequences to reconstruct the phylogenetic relationships among fossorial and aquatic water voles belonging to A. amphibius (formely terrestris) collected in various regions of Europe. We combined 147 new sequences collected mostly in France, Germany and Great Britain, with available datasets from the entire range to provide an up-to-date phylogeny of this species. Phylogenetic and network reconstructions retrieved 4 major lineages all containing fossorial and aquatic morphotypes, discarding the view of each ecotype corresponding to a distinct species. Morphometric analyses of skull shape were performed on a set of aquatic and fossorial populations documenting the main lineages. Fossorial and aquatic populations tend to display convergent morphological features related to their ecology, blurring a part of the phylogenetic signal. Different allometric trajectories related to the constraints of the aquatic vs. subterranean habitats may contribute to this morphological convergence. [less ▲]

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See detailAquatic and terrestrial water voles: phylogeography and morphometrics
chevret, p; helvaci, z; quere, J.P. et al

Poster (2018)

Water voles from the genus Arvicola display an amazing ecological versality, with aquatic and terrestrial populations. Their taxonomic status and evolutionary relationships has caused a long-standing ... [more ▼]

Water voles from the genus Arvicola display an amazing ecological versality, with aquatic and terrestrial populations. Their taxonomic status and evolutionary relationships has caused a long-standing dispute. Two aquatic (sapidus, amphibius) and one fossorial species (scherman) are currently described. We used mitochondrial cytochrome b (cytb) gene sequences to reconstruct the phylogenetic relationships among fossorial and aquatic water voles belonging to A. amphibius (formely terrestris) collected in various regions of Europe. We combined 147 new sequences collected mostly in France, Germany and Great Britain, with available datasets from the entire range to provide an up-to-date phylogeny of this species. Phylogenetic and network reconstructions retrieved 4 major lineages all containing fossorial and aquatic morphotypes, discarding the view of each ecotype corresponding to a distinct species. Morphometric analyses of skull shape were performed on a set of aquatic and fossorial populations documenting the main lineages. Fossorial and aquatic populations tend to display convergent morphological features related to their ecology, blurring a part of the phylogenetic signal. Different allometric trajectories related to the constraints of the aquatic vs. subterranean habitats may contribute to this morphological convergence. [less ▲]

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See detailDipodidae family, In : Handbook of the Mammals of the World, Volume 7: Rodents II.
Michaux, Johan ULiege; Schenbrodt, Georgi

in Wilson, Don E.; Lacher, Thomas E; Mittermeier, Russell A (Eds.) Handbook of the Mammals of the World. (2018)

Chapitre de référence mondiale, concernant la famille des Dipodidae, reprenant l'histoire et la biologie de la famille, ainsi qu'un ensemble de fiches descriptive pour l'ensemble des espèces existant au ... [more ▼]

Chapitre de référence mondiale, concernant la famille des Dipodidae, reprenant l'histoire et la biologie de la famille, ainsi qu'un ensemble de fiches descriptive pour l'ensemble des espèces existant au sein de cette famille [less ▲]

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See detailApport de la génétique pour l’étude de la dynamique des populations de Loutre d’Europe Lutra lutra (Linnaeus, 1758) en France
Pigneur, L.M.; Michaux, Johan ULiege; Caublot, G. et al

in Naturae (2018), 6

Contribution of genetic studies to the understanding of the population dynamics of Eurasian otter (Lutra lutra (Linnaeus, 1758)) The Eurasian otter Lutra lutra (Linnaeus, 1758) experienced a dramatic ... [more ▼]

Contribution of genetic studies to the understanding of the population dynamics of Eurasian otter (Lutra lutra (Linnaeus, 1758)) The Eurasian otter Lutra lutra (Linnaeus, 1758) experienced a dramatic decline in Europe during the 20th century, persisting only in small and spatially isolated populations. Since the 1970s and its legal protection in many regions, the species expanded in range and numbers, which stimulated scientific studies. The simultaneous development of molecular methods allowed scientists to adopt non-invasive sampling techniques for the monitoring of the species. These methods rely on the collection of cues of the species presence and neither requires to capture nor to observe the individuals. These studies improved our knowledge on the biology, population size and population dynamics of the species.The present article summarises the state of the art on otter in Europe based on recent genetic studies conducted throughout the species distribution range in France. We did not aim at an exhaustive review of studies on Eurasian otter, but rather at illustrating to what extent genetic studies contributed to our knowledge on otter biology at different temporal and spatial scales. Thus, innovative studies conducted on River otter Lontra canadensis Schreber, 1777 based on molecular methods were also included. [less ▲]

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See detailThe evolutionary journey of Fv1
Young, G; Yap, MY; Michaux, Johan ULiege et al

in Proceedings of the National Academy of Sciences of the United States of America (2018), 115(40), 10130-10135

Both exogenous and endogenous retroviruses have long been studied in mice, and some of the earliest mouse studies focused on the heritability of genetic factors influencing permissivity and resistance to ... [more ▼]

Both exogenous and endogenous retroviruses have long been studied in mice, and some of the earliest mouse studies focused on the heritability of genetic factors influencing permissivity and resistance to infection. The prototypic retroviral restriction factor, Fv1, is now understood to exhibit a degree of control across multiple retroviral genera and is highly diverse within Mus To better understand the age and evolutionary history of Fv1, a comprehensive survey of the Muroidea was conducted, allowing the progenitor integration to be dated to ∼45 million years. Intact coding potential is visible beyond Mus, and sequence analysis reveals strong signatures of positive selection also within field mice, Apodemus Fv1's survival for such a period implies a recurring and shifting retroviral burden imparting the necessary selective pressures-an influence likely also common to analogous factors. Regions of Fv1 adapt cooperatively, highlighting its preference for repeated structures and suggesting that this functionally constrained aspect of the retroviral capsid lattice presents a common target in the evolution of intrinsic immunity. [less ▲]

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See detailA genome-wide data assessment of the African lion (Panthera leo) population genetic structure and diversity in Tanzania
Smitz, nathalie; Jouvenet, Olivia; Ambwene Ligate, F et al

in PLoS ONE (2018), 13(11),

The African lion (Panthera leo), listed as a vulnerable species on the IUCN Red List of Threatened Species (Appendix II of CITES), is mainly impacted by indiscriminate killing and prey base depletion ... [more ▼]

The African lion (Panthera leo), listed as a vulnerable species on the IUCN Red List of Threatened Species (Appendix II of CITES), is mainly impacted by indiscriminate killing and prey base depletion. Additionally, habitat loss by land degradation and conversion has led to the isolation of some subpopulations, potentially decreasing gene flow and increasing inbreeding depression risks. Genetic drift resulting from weakened connectivity between strongholds can affect the genetic health of the species. In the present study, we investigated the evolutionary history of the species at different spatiotemporal scales. Therefore, the mitochondrial cytochrome b gene (N = 128), 11 microsatellites (N = 103) and 9,103 SNPs (N = 66) were investigated in the present study, including a large sampling from Tanzania, which hosts the largest lion population among all African lion range countries. Our results add support that the species is structured into two lineages at the continental scale (West-Central vs East-Southern), underlining the importance of reviewing the taxonomic status of the African lion. Moreover, SNPs led to the identification of three lion clusters in Tanzania, whose geographical distributions are in the northern, southern and western regions. Furthermore, Tanzanian lion populations were shown to display good levels of genetic diversity with limited signs of inbreeding. However, their population sizes seem to have gradually decreased in recent decades. The highlighted Tanzanian African lion population genetic differentiation appears to have resulted from the combined effects of anthropogenic pressure and environmental/climatic factors, as further discussed. [less ▲]

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See detailBank Voles in Southern Eurasia: Vicariance and Adaptation
Ledevin, Ronan; Chevret, Pascale; Helvaci, Zeycan et al

in Journal of Mammalian Evolution (2018), 25(1), 119-129

Phylogeographic lineages are interpreted as the product of repeated isolation in glacial refugia, leading to vicariant differentiation. Being restricted to a given geographic area could also promote ... [more ▼]

Phylogeographic lineages are interpreted as the product of repeated isolation in glacial refugia, leading to vicariant differentiation. Being restricted to a given geographic area could also promote adaptive divergence in response to local conditions. The role of phylogeny and climate in the evolution of the bank vole (Myodes glareolus) was investigated here, focusing on molar tooth shape, a morphological feature related to the exploitation of food resources. A balanced role of phylogeny and climate was demonstrated. Response to environmental factors led to morphological convergence of bank voles from different lineages living in similar environments, and to within-lineage divergence in extreme environments. An important interaction of climate and phylogeny was found, suggesting that each lineage is living in a particular environment. This lineage-specific adaptation to a range of environmental conditions may have conditioned the potential of post-glacial recolonization of each lineage. Morphological covariation with environmental conditions further highlights the potential of adaptation of this species. [less ▲]

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See detailLiver microbiome of Peromyscus leucopus, a key reservoir host species for emerging infectious diseases in North America
André, Adrien ULiege; Mouton, Alice ULiege; millien, virginie et al

in Infection, Genetics and Evolution: Journal of Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases (2017)

Microbiome studies generally focus on the gut microbiome, which is composed of a large proportion of commensal bacteria. Here we propose a first analysis of the liver microbiomeusing next generation ... [more ▼]

Microbiome studies generally focus on the gut microbiome, which is composed of a large proportion of commensal bacteria. Here we propose a first analysis of the liver microbiomeusing next generation sequencing as a tool to detect potentially pathogenic strains. We used Peromyscus leucopus, the main reservoir host species of Lyme disease in eastern North America, as a model and sequenced V5-V6 regions of the 16S gene from 18 populations in southern Quebec (Canada). The Lactobacillus genus was found to dominate the liver microbiome.We also detected a large proportion of individuals infected by Bartonella vinsonii arupensis, a human pathogenic bacteria responsible for endocarditis, aswell as Borrelia burgdorferi, the pathogen responsible for Lyme disease in North America. We then compared the microbiomes among two P. leucopus genetic clusters occurring on either side of the St. Lawrence River, and did not detect any effect of the host genotype on their liver microbiome assemblage. Finally, we report, for the first time, the presence of B. burgdorferi in a smallmammal host fromthe northern side of the St. Lawrence River, in support of models that have predicted the northern spread of Lyme disease in Canada. [less ▲]

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See detailHow can genetic tools contribute to the study and management of wild fauna?
Pigneur, Lise Marie; Gillet, François; André, adrien et al

Conference (2017)

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See detailThe revolution of new genetic tools for the study of the ecology of rare or elusive species, using non-invasive approaches
Michaux, Johan ULiege

Conference (2017)

Since the last decade, the development of new molecular biology technologies and particularly the Next Generation Sequencing methods have revolutionized the study of biodiversity. Using non-invasive ... [more ▼]

Since the last decade, the development of new molecular biology technologies and particularly the Next Generation Sequencing methods have revolutionized the study of biodiversity. Using non-invasive approaches (collect of faeces, hairs, urine, saliva..), these methods presently allow to detect the existence of cryptic species, to estimate gene flow among isolated populations, their population sizes but also to study the ecology of rare or elusive species, like their diets, their microbiomes, their sex ratio, their daily movements or their putative niche overlapping or hybridations with closely related species. More particularly, these new genetic methods are interesting for the study of threatened species, in order to propose the best management measures for them. Using different examples developed in my laboratory, I will enhance the interest of such studies, as complementary tools to other methodologies developed in the fields. As an example, these studies evidenced the most precise information concerning the diets of the Polar bear populations living in northern Canada, the European otter living in France, the Pyrenean Desman, the aquatic shrew or different African and Asian primate species, like the apes and the gorillas. These informations are of a prime interest to better understand the impact of habitat destruction on the food availability, and how these threatened species can adapt themselves to survive to global changes. On a more fundamental aspect, these studies evidenced how species having a close ecological niche, like the Pyrenean desman and the aquatic shrew can live in a same area, by shifting their diets, in order to avoid competition. [less ▲]

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See detailStudy of the coexistence pattern of two alternative phenotypes in the palmate newt (Lissotriton helveticus), the answer from microsatellite markers.
Oromi, Neus; Michaux, Johan ULiege; Denoel, Mathieu

Conference (2017)

Facultative paedomorphosis is a polymorphism that occurs in several species of newts and salamanders. In contrast to metamorphosis, paedomorphosis implies the retention of larval traits – such as external ... [more ▼]

Facultative paedomorphosis is a polymorphism that occurs in several species of newts and salamanders. In contrast to metamorphosis, paedomorphosis implies the retention of larval traits – such as external gills in reproductive adults. The coexistence of the two phenotypes in the same reproductive habitat brings then the question of their sexual compatibility. Indeed, different sexual strategies may lead to some sexual isolation between phenotypes. To determine whether the two phenotypes are part of a single population or if they show some isolation, we undertook a genetic analysis on both coexisting phenotype from a population of the palmate newt (Lissotriton helveticus) in Larzac (France). 10 polymorphic microsatellite markers were used to genotype 96 individuals (48 meta- and 48 paedomorphs), coexisting in the same pond. Genetic diversity was similar in the two phenotypes and the Fst- and Fis-values were low, suggesting a high gene flow and sexual compatibility between meta- and paedomophs. In addition, several markers were significantly in Hardy-Weinberg (HW) disequilibrium with heterozygote excess. The results suggest the absence of inbreeding with a high gene flow between phenotypes. This sexual compatibility may be an adaptation to local selection pressures, contributing to the persistence of the polyphenism. Some markers appear to present HW disequilibrium suggesting selection, non-random mating or random genetic drift that could be interesting to analyse in future studies. [less ▲]

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See detailExpand or disappear ? Why related Mustelid species follow different roads. Lessons from the genetic study of minks, polecat and otter
Michaux, Johan ULiege

Conference (2017)

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. On one hand, some species undergo strong reduction of their populations due ... [more ▼]

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. On one hand, some species undergo strong reduction of their populations due to the fragmentation of their habitats, the competition with other species, the pollution or degradation of their habitat or the appearance of new diseases. On the other hand, many species tend to expand their distribution range) and can even be considered as invasive species in some cases. The aim of our presentation will be to better understand which biological factors could lead to decrease populations of a species until extinction or in contrast, could help a species exanding its population densities and distribution area. These hypotheses will be illustrated by our recent results obtained through the genetic study of the European mink Mustela lutreola, the American mink Neovison vison, the polecat Mustela putorius and the European otter Lutra lutra (Cabria et al. 2011; Michaux et al. 2005; Pigneur et al., In Prep). [less ▲]

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See detailComparison of diet and prey selectivity of the Pyrenean desman and the Eurasian water shrew using next-generation sequencing methods
Biffi, M.; Laffaille, P.; Jabiol, J. et al

in Mammalian Biology (2017), 87

In this study, the interactions between two semi-aquatic mammals, the endangered Pyrenean desman Galemys pyrenaicus and the Eurasian water shrew Neomys fodiens, were investigated through the analysis of ... [more ▼]

In this study, the interactions between two semi-aquatic mammals, the endangered Pyrenean desman Galemys pyrenaicus and the Eurasian water shrew Neomys fodiens, were investigated through the analysis of their summer diet using next-generation sequencing methods, combined with analyses of prey selectivity and trophic overlap. The diet of these predators was highly diverse including 194 and 205 genera for G. pyrenaicus and N. fodiens respectively. Overall, both species exhibited rather non-selective foraging strategies as the most frequently consumed invertebrates were also the most frequent and abundant in the streams. This supported a generalist foraging behaviour for G. pyrenaicus and N. fodiens in the study area. The Pianka index (0.4) indicated a significant but moderate dietary overlap as G. pyrenaicus mostly relied on prey with aquatic stages whereas prey of N. fodiens were mainly terrestrial. Moreover, no difference in G. pyrenaicus prey consumption was found in presence or absence of N. fodiens. A differential use of trophic resources through mechanisms such as plastic feeding behaviour or differences in foraging micro-habitat are likely to facilitate the coexistence between these two mammal species. © 2017 Deutsche Gesellschaft für Säugetierkunde [less ▲]

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