Population genomics of Corsican wildcats: Paving the way toward a new subspecies within the Felis silvestris spp. complex?

In the context of the current extinction crisis, identifying new conservation units is pivotal to the development of sound conservation measures, especially in highly threatened taxa such as felids. Corsican wildcats are known by Corsican people since a very long time but have been little studied. Meaningful information about their phylogenetic position is lacking.

Breaking down population density into different components to better understand its spatial variation.

Background: Population size and densities are key parameters in both fundamental and applied ecology, as they affect population resilience to density-dependent processes, habitat changes and stochastic events. Efficient management measures or species conservation programs thus require accurate estimates of local population densities across time and space, especially for continuously distributed species. For social species living in groups, population density depends on different components, namely the number of groups and the group size, for which relative variations in space may originate from different environmental factors.

Spatial variance-mass allometry of population density in felids from camera-trapping studies worldwide.

Power laws are cornerstone relationships in ecology and evolutionary biology. The density-mass allometry (DMA), which predicts an allometric scaling of population abundance, and Taylor's law (TL), which predicts a decrease in the population abundance variation along with a decrease in population density, have enhanced our knowledge of inter- and intra-specific variation in population abundance. When combined, these two power laws led to the variance-mass allometry (VMA), which states that larger species have lower spatial variation in population density than smaller species.

Altitude shapes the environmental drivers of large-scale variation in abundance of a widespread mammal species.

Aim: Habitat quality and heterogeneity directly influence the distribution and abundance of organisms at different spatial scales. Determining the main environmental factors driving the variation in species abundance is crucial to understand the underlying ecological processes, and this is especially important for widely distributed species living in contrasting environments. However, the responses to environmental variation are usually described at relatively small spatial scales.

Does host socio-spatial behavior lead to a fine-scale spatial genetic structure in its associated parasites?

Gastro-intestinal nematodes, especially Haemonchus contortus, are widespread pathogenic parasites of small ruminants. Studying their spatial genetic structure is as important as studying host genetic structure to fully understand host-parasite interactions and transmission patterns. For parasites having a simple life cycle (e.

Quantifying the contribution of immigration to population dynamics: a review of methods, evidence and perspectives in birds and mammals.

The demography of a population is often reduced to the apparent (or local) survival of individuals and their realised fecundity within a study area defined according to logistical constraints rather than landscape features. Such demographics are then used to infer whether a local population contributes positively to population dynamics across a wider landscape context. Such a simplistic approach ignores a fundamental process underpinning population dynamics: dispersal.

Data gaps and opportunities for comparative and conservation biology.

Biodiversity loss is a major challenge. Over the past century, the average rate of vertebrate extinction has been about 100-fold higher than the estimated background rate and population declines continue to increase globally. Birth and death rates determine the pace of population increase or decline, thus driving the expansion or extinction of a species.

Both candidate gene and neutral genetic diversity correlate with parasite resistance in female Mediterranean mouflon.

Background: Parasite infections can have substantial impacts on population dynamics and are accordingly a key challenge for wild population management. Here we studied genetic mechanisms driving parasite resistance in a large herbivore through a comprehensive approach combining measurements of neutral (16 microsatellites) and adaptive (MHC DRB1 exon 2) genetic diversity and two types of gastrointestinal parasites (nematodes and coccidia).

Results: While accounting for other extrinsic and intrinsic predictors known to impact parasite load, we show that both neutral genetic diversity and DRB1 are associated with resistance to gastrointestinal nematodes.

Genetic Characterization of Toxoplasma gondii DNA Samples Isolated From Humans Living in North America: An Unexpected High Prevalence of Atypical Genotypes.

Background: Whereas in Europe most of Toxoplasma gondii genotypes belong to the type II lineage, in Latin America, type II is rare and atypical strains predominate. In North America, data on T. gondii genotypes in humans are scarce.

A fast likelihood solution to the genetic clustering problem.

The investigation of genetic clusters in natural populations is an ubiquitous problem in a range of fields relying on the analysis of genetic data, such as molecular ecology, conservation biology and microbiology. Typically, genetic clusters are defined as distinct panmictic populations, or parental groups in the context of hybridisation. Two types of methods have been developed for identifying such clusters: model-based methods, which are usually computer-intensive but yield results which can be interpreted in the light of an explicit population genetic model, and geometric approaches, which are less interpretable but remarkably faster.

Introduction history overrides social factors in explaining genetic structure of females in Mediterranean mouflon.

Fine-scale spatial genetic structure of populations results from social and spatial behaviors of individuals such as sex-biased dispersal and philopatry. However, the demographic history of a given population can override such socio-spatial factors in shaping genetic variability when bottlenecks or founder events occurred in the population. Here, we investigated whether socio-spatial organization determines the fine-scale genetic structure for both sexes in a Mediterranean mouflon (×  sp.

Phylogeography of Toxoplasma gondii points to a South American origin.

Toxoplasma gondii, a protozoan found ubiquitously in mammals and birds, is the etiologic agent of toxoplasmosis, a disease causing substantial public health burden worldwide, including about 200,000 new cases of congenital toxoplasmosis each year. Clinical severity has been shown to vary across geographical regions, with South America exhibiting the highest burden. Unfortunately, the drivers of these heterogeneities are still poorly understood, and the geographical origin and historical spread of the pathogen worldwide are currently uncertain.

On the evolutionary consequences of increasing litter size with multiple paternity in wild boar (Sus scrofa scrofa).

Understanding how some species may be able to evolve quickly enough to deal with anthropogenic pressure is of prime interest in evolutionary biology, conservation, and management. Wild boar (Sus scrofa scrofa) populations keep growing all over Europe despite increasing hunting pressure. In wild boar populations subject to male-selective harvesting, the initially described polygynous mating system may switch to a promiscuous/polyandrous one.

Staphylococcus aureus infective endocarditis versus bacteremia strains: Subtle genetic differences at stake.

Infective endocarditis (IE)((1)) is a severe condition complicating 10-25% of Staphylococcus aureus bacteremia. Although host-related IE risk factors have been identified, the involvement of bacterial features in IE complication is still unclear. We characterized strictly defined IE and bacteremia isolates and searched for discriminant features.

The rural-urban effect on spatial genetic structure of type II Toxoplasma gondii strains involved in human congenital toxoplasmosis, France, 2002-2009.

Congenital toxoplasmosis involves Toxoplasma gondii type II strains in 95% of cases in France. We used spatial principal component analysis (sPCA) and 15 microsatellite markers to investigate the spatial genetic structure of type II strains involved in 240 cases of congenital toxoplasmosis in France from 2002 through 2009. Mailing addresses of patients were geo-referenced a posteriori in decimal degrees and categorized into urban or rural areas of residence.

RAD sequencing and genomic simulations resolve hybrid origins within North American Canis.

Top predators are disappearing worldwide, significantly changing ecosystems that depend on top-down regulation. Conflict with humans remains the primary roadblock for large carnivore conservation, but for the eastern wolf (Canis lycaon), disagreement over its evolutionary origins presents a significant barrier to conservation in Canada and has impeded protection for grey wolves (Canis lupus) in the USA. Here, we use 127,235 single-nucleotide polymorphisms (SNPs) identified from restriction-site associated DNA sequencing (RAD-seq) of wolves and coyotes, in combination with genomic simulations, to test hypotheses of hybrid origins of Canis types in eastern North America.

Environmental determinants of spatial and temporal variations in the transmission of Toxoplasma gondii in its definitive hosts.

Toxoplasmosis is a major zoonosis, and its prevention requires multiple approaches due to the complex life-cycle of its causative agent, Toxoplasma gondii. Environmental contamination by oocysts is a key factor in the transmission of T. gondii to both humans and meat-producing animals; however, its spatial and temporal variations are poorly understood.

The relationship between phenotypic variation among offspring and mother body mass in wild boar: evidence of coin-flipping?

1. In highly variable environments, the optimal reproductive tactics of iteroparous organisms should minimize variance in yearly reproductive success to maximize the long-term average reproductive success. To minimize among-year variation in reproductive success, individuals can either minimize the variance in the number of offspring produced at each reproductive attempt (classical bet-hedging) or maximize the phenotypic diversity of offspring produced within or among reproductive attempts (coin-flipping).

Linking genetic diversity and temporal fluctuations in population abundance of the introduced feral cat (Felis silvestris catus) on the Kerguelen archipelago.

Linking temporal variations of genetic diversity, including allelic richness and heterozygosity, and spatio-temporal fluctuations in population abundance has emerged as an important tool for understanding demographic and evolutionary processes in natural populations. This so-called genetic monitoring was conducted across 12 consecutive years (1996-2007) at three sites for the feral cat, introduced onto the Kerguelen archipelago fifty years ago. Temporal changes in allelic richness and heterozygosity at 18 microsatellite DNA loci were compared with temporal changes in the adult population abundance index, obtained by typical demographic monitoring.

Human impact on genetic diversity of Toxoplasma gondii: example of the anthropized environment from French Guiana.

In French Guiana, severe cases of toxoplasmosis in immunocompetent patients are associated with atypical strains of Toxoplasma gondii linked to a wild neotropical rainforest cycle and a higher genetic diversity than usually observed for T. gondii isolates from anthropized environment. This raises the question of the impact of anthropization of the natural environment, on genetic diversity and on the population structure of T.

Additional haplogroups of Toxoplasma gondii out of Africa: population structure and mouse-virulence of strains from Gabon.

Background: Toxoplasma gondii is found worldwide, but distribution of its genotypes as well as clinical expression of human toxoplasmosis varies across the continents. Several studies in Europe, North America and South America argued for a role of genotypes in the clinical expression of human toxoplasmosis. Genetic data concerning T.

Discriminant analysis of principal components: a new method for the analysis of genetically structured populations.

Background: The dramatic progress in sequencing technologies offers unprecedented prospects for deciphering the organization of natural populations in space and time. However, the size of the datasets generated also poses some daunting challenges. In particular, Bayesian clustering algorithms based on pre-defined population genetics models such as the STRUCTURE or BAPS software may not be able to cope with this unprecedented amount of data.