Stationary distributions of microsatellite loci between divergent population groups of the European rabbit (Oryctolagus cuniculus).Mol

Previous analysis of rnitochondrial DNA polymorphism in the native range of the European rabbit (Oryctolagus cuniculus) demonstrated the occurrence of two highly divergent (2 Myr) maternal lineages with a well-defined geographical distribution. Analysis of both protein and immunoglobulin polymorphisms are highly concordant with this pattern of differentiation. However, the present analysis of nine polymorphic microsatellite loci (with a total of 169 alleles) in 24 wild populations reveals severe allele-size homoplasy which vastly underestimates divergence between the main groups of populations in Iberia. Nonetheless, when applied to more recent historical phenomena, this same data set not only confirms the occurrence of a strong bottleneck associated with the colonization of Mediterranean France but also suggests a two-step dispersal scenario that began with gene flow from northern Spain through the Pyrenean barrier and subsequent range expansion into northern France. The strength and appropriateness of applying microsatellites to more recent evolutionary questions is highlighted by the fact that both mtDNA and protein markers lacked the allelic diversity necessary to properly evaluate the colonization of France. The welldocumented natural history of European rabbit populations provides an unusually comprehensive framework within which one can appraise the advantages and limitations of microsatellite markers in revealing patterns of genetic differentiation that have occurred across varying degrees of evolutionary time. The degree of size homoplasy presented in our data should serve as a warning to those drawing conclusions from microsatellite data sets which lack a set of complementary comparative markers, or involve long periods of evolutionary history, even within a single species

Identification of genes involved in genodermatoses : Example of naso-plantar keratodermia in the french breed dogue de bordeaux

The genetic structure of the canine species, with over 300 breeds created and modified by man, provides a unique model to identify genes and alleles responsible for genetic diseases. Our laboratory has been working for over ten years to deliver genomic resources to further our understanding of the genetic bases of particular traits or of genetic diseases in dogs, with a view to using them as models for the same traits in humans. We present here our chromosome mapping studies carried out on candidate genes or genes involved in genodermatoses, as well as our on-going molecular genetics study on naso-plantar keratodermia in the French breed Dogue de Bordeaux.Compte tenu de la structure génétique de l'espèce canine, avec plus de 300 races construites et façonnées par l'homme, le chien présente un intérêt tout à fait particulier pour identifier les gènes et les allèles responsables de maladies génétiques. Notre laboratoire travaille depuis plus de 10 ans à produire les connaissances génomiques nécessaires à la compréhension des bases génétiques de traits particuliers ou de maladies génétiques chez le chien, afin de les utiliser comme modèles des mêmes traits chez l'homme. Nous exposerons ici les travaux déjà effectués sur le positionnement sur les chromosomes canins de gènes candidats ou impliqués dans des génodermatoses, ainsi que le travail de génétique moléculaire en cours sur la kératodermie naso-plantaire, chez le Dogue de Bordeaux

Progressive Retinal Atrophy in the Border Collie: A new XLPRA

<p>Abstract</p> <p>Background</p> <p>Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG).</p> <p>Results</p> <p>Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests.</p> <p>Conclusion</p> <p>Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3) and propose it as a potential model for the homologous human disease, X-Linked Retinitis Pigmentosa.</p

Coexistence of two sympatric cryptic bat species in French Guiana: insights from genetic, acoustic and ecological data

International audienceBackground: The distinction between lineages of neotropical bats from the Pteronotus parnellii species complex has been previously made according to mitochondrial DNA, and especially morphology and acoustics, in order to separate them into two species. In these studies, either sample sizes were too low when genetic and acoustic or morphological data were gathered on the same individuals, or genetic and other data were collected on different individuals. In this study, we intensively sampled bats in 4 caves and combined all approaches in order to analyse genetic, morphologic, and acoustic divergence between these lineages that live in the same caves in French Guiana

Parallel adaptation of rabbit populations to myxoma virus.

In the 1950s the myxoma virus was released into European rabbit populations in Australia and Europe, decimating populations and resulting in the rapid evolution of resistance. We investigated the genetic basis of resistance by comparing the exomes of rabbits collected before and after the pandemic. We found a strong pattern of parallel evolution, with selection on standing genetic variation favoring the same alleles in Australia, France, and the United Kingdom. Many of these changes occurred in immunity-related genes, supporting a polygenic basis of resistance. We experimentally validated the role of several genes in viral replication and showed that selection acting on an interferon protein has increased the protein's antiviral effect.This work was supported by grants from the Programa Operacional Potencial Humano–Quadro de Referência Estratégica Nacional funds from the European Social Fund and Portuguese Ministério da Ciência, Tecnologia e Ensino Superior to M.C. (IF/00283/2014/CP1256/CT0012), to P.J.E. (IF/00376/2015) and to J.M.A. (SFRH/BD/72381/2010). AM was supported by the European Research Council (grant 647787-LocalAdaptation). FJ was supported by the European Research Council (grant 281668). LL was supported by the European Research Council grant (339941-ADAPT). McFadden Lab is supported by National Institute of Health (NIH) grant R01 AI080607. S.C.G. holds a Sir Henry Dale Fellowship, co-funded by the Wellcome Trust and the Royal Society (098406/Z/12/Z)

Les tests génétiques chez le chien

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