0000000000098985
AUTHOR
Jean-françois Cosson
La diffusion des pullulations de campagnols terrestres
Mieux connaître le phénomène de pullulation du campagnol terrestre est nécessaire pour lutter plus efficacement contre ce " dévastateur des prairies ". Cela exige de se placer à plusieurs échelles spatiales différentes. De l'étude du comportement individuel (échelle parcellaire) jusqu'à l'extension de ses populations (échelle régionale), plusieurs niveaux d'analyse sont possibles. Dans ce chapitre, les pullulations sont abordées comme un processus de diffusion spatio-temporelle, qui n'est véritablement observable qu'au niveau régional. Un premier point consiste à décrire et à mesurer cette diffusion. Des éléments explicatifs sur les principaux facteurs paysagers exerçant une influence sur c…
Cost-distance defined by a topological function of landscape
International audience; Distance is a basic concept in the domain of animal species motion. Cost distances, rather than Euclidian distances, are more and more used in order to have a more realistic measure, on the basis of resistance values assigned to each landscape class. We propose here a method to compute resistance values by using topological functions of landscape, i.e. by taking account of the proximity of habitat/non-habitat edges, with continuous functions. An example is given when comparing cost distances and the propagation of water vole in the massif of Jura (France). The comparison with usual cost distances gives information about the ecological assumptions. The results show al…
Microevolution of bank voles (Myodes glareolus) at neutral and immune-related genes during multiannual dynamic cycles: consequences for Puumala hantavirus epidemiology.
ABSTRACTUnderstanding how host dynamics, including variations of population size and dispersal, may affect the epidemiology of infectious diseases through ecological and evolutionary processes is an active research area. Here we focus on a bank vole (Myodes glareolus) metapopulation surveyed in Finland between 2005 and 2009. Bank vole is the reservoir of Puumala hantavirus (PUUV), the agent of nephropathia epidemica (NE, a mild form of hemorrhagic fever with renal symptom) in humans.M glareoluspopulations experience multiannual density fluctuations that may influence the level of genetic diversity maintained in bank voles, PUUV prevalence and NE occurrence. We examine bank vole metapopulati…
Phylogeography of two cryptic species of African desert jerboas (Dipodidae: Jaculus)
The lesser Egyptian jerboa Jaculus jaculus is a desert dwelling rodent that inhabits a broad Arabian–Saharan arid zone. Recently, two distant sympatric lineages were described in North-West Africa, based on morphometric and molecular data, which may correspond to two cryptic species. In the current study, phylogenetic relationships and phylogeographical structure among those lineages and geographical populations from North Africa and the Middle East were investigated. The phylogeographical patterns and genetic diversity of the cytochrome b gene (1110 bp) were addressed on 111 jerboas from 41 localities. We found that the variation in Africa is partitioned into two divergent mitochondrial cl…
Consequences of organ choice in describing bacterial pathogen assemblages in a rodent population
SUMMARYHigh-throughput sequencing technologies now allow for rapid cost-effective surveys of multiple pathogens in many host species including rodents, but it is currently unclear if the organ chosen for screening influences the number and identity of bacteria detected. We used 16S rRNA amplicon sequencing to identify bacterial pathogens in the heart, liver, lungs, kidneys and spleen of 13 water voles (Arvicola terrestris) collected in Franche-Comté, France. We asked if bacterial pathogen assemblages within organs are similar and if all five organs are necessary to detect all of the bacteria present in an individual animal. We identified 24 bacteria representing 17 genera; average bacterial…