One of the reasons for animals not to grow as fast as they potentially could is that fast growth has been shown to be associated with reduced lifespan. However, we are still lacking a clear description of the reality of growth-dependent modulation of ageing mechanisms in wild animals. Using the particular growth trajectory of small king penguin chicks naturally exhibiting higher-than-normal growth rate to compensate for the winter break, we tested whether oxidative stress and...

Behavior and genetic structure are intimately related: mating patterns and patterns of movement between groups or populations influence the movement of genetic variation across the landscape and from one generation to the next. In hybrid zones, the behavior of the hybridizing taxa can also have an important impact on the incidence and outcome of hybridization events. Hybridization between yellow baboons and anubis baboons has been well-documented in the Amboseli basin of Kenya, where more anubis-like...

DNA metabarcoding corresponds to the DNA-based identification of multiple species from a single complex and degraded environmental sample. We developed new sampling and extraction protocols suitable for DNA metabarcoding analyses, targeting soil extracellular DNA. The proposed sampling protocol has been designed to reduce as much as possible the influence of the local heterogeneity by processing large amount of soil, resulting from the mixing of many different cores. The DNA extraction is based on the use...

BACKGROUND: Tunicates represent a key metazoan group as the sister-group of vertebrates within chordates. The six complete mitochondrial genomes available so far for tunicates have revealed distinctive features. Extensive gene rearrangements and particularly high evolutionary rates have been evidenced with regard to other chordates. This peculiar evolutionary dynamics has hampered the reconstruction of tunicate phylogenetic relationships within chordates based on mitogenomic data. RESULTS: In order to further understand the atypical evolutionary dynamics of the mitochondrial...

A good understanding of mammalian societies requires measuring patterns and comprehending processes of dispersal in each sex. We investigated dispersal behaviour in arvicoline rodents, a sub-family of mammals widespread in northern temperate environments and characterised by a multivoltine life cycle. In arvicoline rodents, variation in life history strategies occurs along a continuum from precocial to delayed maturation that reflects seasonal and ecological fluctuations. We compared dispersal across and within species focusing on the effects of...

Bilaterian animals have a Hox gene cluster essential for patterning the main body axis, and a ParaHox gene cluster. Comparison of Hox and ParaHox genes has led workers to postulate that both clusters originated from the duplication of an ancient cluster named ProtoHox, which contained up to four genes with at least the precursors of anterior and posterior Hox/ParaHox genes. However, the way in which genes diversified within the ProtoHox, Hox and ParaHox clusters remains...

Eumelanin and pheomelanin are the most common vertebrate pigments. They generate different colours and are synthesized under different physiological conditions. While pheomelanogenesis requires high levels of a key intracellular antioxidant (glutathione, GSH), eumelanogenesis is inhibited by GSH. This implies that species that present the molecular basis to produce large amounts of pheomelanin might be more limited to perform other costly processes that generate oxidative stress than species that produce eumelanin. Brain development requires large amounts...

Sexually antagonistic genetic variation, where optimal values of traits are sex-dependent, is known to slow the loss of genetic variance associated with directional selection on fitness-related traits. However, sexual antagonism alone is not sufficient to maintain variation indefinitely. Selection of rare forms within the sexes can help to conserve genotypic diversity. We combined theoretical models and a field experiment with Myodes glareolus to show that negative frequency-dependent selection on male dominance maintains variation in sexually...

AFLP-based genome scans are widely used to study the genetics of adaptation and to identify genomic regions potentially under selection. However, this approach usually fails to detect the actual genes or mutations targeted by selection due to the difficulty to obtain the sequences from AFLP fragments. Here we combine classical AFLP outlier detection to 454 sequencing of AFLP fragments obtained from chosen individuals to obtain the sequence of outliers. We applied this approach to the...

Although theory established the necessary conditions for diversification in temporally heterogeneous environments, empirical evidence remains controversial. One possible explanation is the difficulty of designing experiments including the relevant range of temporal grains and the appropriate environmental tradeoffs. Here, we experimentally explore the impact of the grain on the diversification of the bacterium Pseudomonas fluorescens SBW25 in a temporally fluctuating environment by including twenty different pairs of environments and four temporal grains. In general, higher levels...

Migration is a complex trait although little is known about genetic correlations between traits involved in such migration syndromes. To assess migratory responses to climate change, we need information on genetic constraints on evolutionary potential of arrival dates in migratory birds. Using two long term data sets on barn swallows Hirundo rustica (from Spain and Denmark), we show for the first time in wild populations that spring arrival dates are phenotypically and genetically correlated with...

Populations of migratory birds differ in their direction of migration with neighboring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by re-colonization. Given that studies have shown significant...

In the marine environment, differential gene exchange between partially reproductively isolated taxa can result in introgression that extends over long distances due to high larval dispersal potential. However, the degree to which this process contributes to inter-locus variance of genetic differentiation within introgressed populations remains unclear. Using a genome-scan approach in the Indo-Pacific eel Anguilla marmorata, we investigated the degree of interpopulation genetic differentiation, the rate of introgression, and within-population genetic patterns at 858 AFLP...

Melanin is mainly found in the integument of animals, but it also appears in several extracutaneous tissues. The presence of melanin in testes has been anecdotally reported in all vertebrate groups, but the causes and functions of this melanin remain unknown. Similar to other extracutaneous melanins, testicular melanin may protect male germ cells from oxidative stress. Given the high respiratory activity of spermatozoa, oxidative stress generated by mitochondrial dysfunction as a consequence of mtDNA mutations...

Plasmodium falciparum is the major human malaria agent responsible for 200 to 300 million infections and one to three million deaths annually, mainly among African infants. The origin and evolution of this pathogen within the human lineage is still unresolved. A single species, P. reichenowi, which infects chimpanzees, is known to be a close sister lineage of P. falciparum. Here we report the discovery of a new Plasmodium species infecting Hominids. This new species has...

In genetically diverse insect societies (polygynous or polyandrous queens), the production of new queens can set the ground for competition among lineages. This competition can be very intense when workers can reproduce using thelytoky as worker patrilines that manage to produce new queens gain a huge benefit. Selection at the individual level might then lead to the evolution of cheating genotypes, i.e. genotypes that reproduce more than their fair share. We studied the variation in...

Evolutionary processes such as migration, genetic drift, and natural selection are thought to play a prominent role in species invasions into novel environments. However, few empirical studies have explored the mechanistic basis of invasion in an evolutionary framework. One promising tool for inferring evolutionarily important changes in introduced populations is the genetic variance-covariance matrix (G matrix). G matrix comparisons allow for the inference of changes in the genetic architecture of introduced populations relative to their...

Earthworms are known for their important role within the functioning of an ecosystem, and their diversity can be used as an indicator of ecosystem health. To date, earthworm diversity has been investigated through conventional extraction methods such as handsorting, soil washing or the application of a mustard solution. Such techniques are time-consuming and often difficult to apply. We showed that combining DNA metabarcoding and next generation sequencing facilitates the identification of earthworm species from soil...

Microsatellites (or SSR: simple sequence repeat) are among the most frequently used DNA markers in many areas of research. The use of microsatellite markers is limited by the difficulties involved in their de novo isolation from species for which no genomic resources are available. We describe here a high-throughput method for isolating microsatellite markers based on coupling multiplex microsatellite enrichment and Next-Generation Sequencing on 454 GS-FLX Titanium platforms. The procedure was calibrated on a model...

We investigated sex-specificities in the evolutionary processes shaping Y chromosome, autosomes and mitochondrial DNA patterns of genetic structure in the Valais shrew (Sorex antinorii), a mountain dwelling species with a hierarchical distribution. Both hierarchical analyses of variance and isolation-by-distance analyses revealed patterns of population structure that were not consistent across maternal, paternal and bi-parentally inherited markers. Differentiation on a Y microsatellite was lower than expected from the comparison with autosomal microsatellites and mtDNA, and it...

Relatively few species have been able to colonize extremely cold alpine environments. We investigate the role played by the cushion life form in the evolution of climatic niches in the plant genus Androsace s.l., which spreads across the mountain ranges of the Northern Hemisphere. Using robust methods that account for phylogenetic uncertainty, intraspecific variability of climatic requirements and different life history evolution scenarios, we show that climatic niches of Androsace s.l. exhibit low phylogenetic signal...

Speciation with gene flow may be more common than generally thought making detailed understanding of the extent and pattern of genetic divergence between geographically isolated populations useful. Species of the Drosophila simulans complex provide a good model for speciation and evolutionary studies; understanding their population genetic structure will increase our understanding of the context in which speciation has occurred. Here we describe the genetic diversity and the genetic differentiation, at mitochondrial and nuclear loci, of...

The impact of ecology and social organisation on genetic structure at landscape spatial scales, where gene dynamics shape evolution as well as determine susceptibility to habitat fragmentation, is poorly understood. Attempts to assess these effects must take into account the potentially confounding effects of history. We used microsatellites to compare genetic structure in seven bat species with contrasting patterns of roosting ecology and social organisation, all of which are co-distributed in an ancient forest habitat...

Diet analysis is a prerequisite to fully understand the biology of a species and the functioning of ecosystems. For carnivores, traditional diet analyses mostly rely upon the morphological identification of undigested remains in the feces. Here, we developed a methodology for carnivore diet analyses based on next generation sequencing. We applied this approach to the analysis of the vertebrate component of leopard cat diet in two ecologically distinct regions in northern Pakistan. Despite being a...

Environmental changes, such as climate change, lead to the opening of new niches. In such situations, species that adapt to new niches can survive and/or expand their ranges. However, gene flow can hamper genetic adaptation to new environments. Alternatively, recent models have highlighted the importance of phenotypic plasticity in tracking environmental change. In this study, we illustrate how plasticity allows an amphibian species to exploit two very different climatic niches under continuous gene flow. In...