Suprafamilial relationships among Rodentia and the phylogenetic effect of removing fast-evolving nucleotides in mitochondrial, exon and intron fragments

The number of rodent clades identified above the family level is contentious, and to date, no consensus has been reached on the basal evolutionary relationships among all rodent families. Rodent suprafamilial phylogenetic relationships are investigated in the present study using approximately 7600 nucleotide characters derived from two mitochondrial genes (Cytochrome b and 12S rRNA), two nuclear exons (IRBP and vWF) and four nuclear introns (MGF, PRKC, SPTBN, THY). Because increasing the number of nucleotides does not necessarily increase phylogenetic signal (especially if the data is saturated), we assess the potential impact of saturation for each dataset by removing the fastest-evolving positions that have been recognized as sources of inconsistencies in phylogenetics

High Genetic Differentiation Among French Populations of the Orsini's Viper (Vipera ursinii ursinii) Based on Mitochondrial and Microsatellite Data: Implications for Conservation Management

The Orsini's viper (Vipera ursinii) is one of the most threatened snakes in Europe due to its highly fragmented distribution and specific open environment (steppic habitat) requirement. French populations are isolated on top of mountain massifs of the southern Prealps/Alps. Mitochondrial sequences (cytochrome b) and 6 microsatellite loci have been used to estimate the levels of genetic diversity and isolation within and among 11 French fragmented populations (a total of 157 individuals). Eleven cytochrome b haplotypes with a limited divergence were observed (mean divergence between haplotypes: 0.31%). However, we detected considerable genetic differentiation among populations (global FST = 0.76 and 0.26 for mitochondrial and nuclear DNA, respectively). Results indicate that 3 populations possibly went through a bottleneck and 1 population showed low genetic diversity compared with the others. Although a significant isolation by distance was detected for both markers, strong differentiation was also observed between geographically close populations, probably due to the ragged landscape that constitutes a serious barrier to gene flow owing to the limited dispersal capability of the viper. Despite some discrepancies between the 2 markers, 8 Management Units have been identified and should be considered for future management project

Structure genique et chromosomique des populations robertsoniennes de Mus musculus domesticus en Italie du nord : discussion du modele de speciation stasipatrique

SIGLECNRS T 57431 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Genetic variation of the weasel (Mustela nivalis) in Corsica based on mitochondrial control region sequences

International audienc

Is increased chromosomal diversity in house mice from Lombardy (Italy) congruent with genic divergence?

International audienceRecent studies in metacentric (MC) populations of the house mouse, Mus musculus domesticus, singled out underdominance more so than recombination suppression as the foremost barrier to gene flow. Here, MC populations from Lombardy (Italy) were sampled to identify the nature and strength of the barriers to gene flow. The chromosomal analysis recovered the three major MC populations (abbreviated to IBIN, IGAL, both with 2n = 24 and ICRE, 2n = 22), but revealed the existence of a new one (IONE, 2n = 24) which likely derived from IGAL through a single WART (Whole‐Arm Reciprocal Translocation). This, once again, highlights the paramount role of WARTs in the chromosomal diversification of this subspecies. Contacts between MC and standard populations coincided with rivers confirming these hybrid zones as tension zones. Divergence between populations was estimated using available allozyme data. Although the overall low genetic structure globally agreed with the chromosome structure, a large variation in divergence levels was retrieved that only partially matched the underdominance degree. This disparity from expectations highlighted the additional contribution of physical barriers and geographic isolation to the differential rate of evolution of the MC populations of the house mouse

Phylogenetic relationships of the five extant Rhinoceros species (Rhinocerotidae, Perissodactyla) based on mitochondrial cytochrome b and 12S rRNA genes.

International audienceA major question in rhinocerotid phylogenetics concerns the position of the Sumatran rhinoceros (Dicerorhinus sumatrensis) with regard to the other extant Asian (Rhinoceros unicornis and R. sondaicus) and African (Diceros bicornis and Ceratotherium simum) species. We have examined this particular question through the phylogenetic analysis of the complete sequences of the mitochondrial 12S rRNA and cytochrome b genes. Three additional perissodactyls (one tapir and two equids) plus several outgroup cetartiodactyls were included in the analysis. The analysis identified a basal rhinocerotid divergence between the African and the Asian species, with the Sumatran rhinoceros forming the sister group of the genus Rhinoceros. We estimate the Asian and African lineages to have diverged at about 26 million years before present

Phylogeography of oribi antelope in South Africa: evolutionary versus anthropogenic panmixia

The increased rate of human-driven change is a major threat to biodiversity. Although there is sufficient evidence to suggest that species notably alter their ranges, facilitation of such movement for larger vertebrate species often places burdens on management agencies. Oribi antelope (Ourebia ourebi ourebi) in South Africa continue to experience dramatic decreases in range and numbers. Animals have and continue to be translocated for conservation, but also aesthetic and financial reasons. Initial translocations were done in the absence of any thought or understanding of genetic structure, while for the past two decades a conservative best-practice approach was adopted, but in the absence of any specific genetic information. Here, we use two mitochondrial and one nuclear fragment to report the phylogeographic structure in oribi antelope across South Africa. Our data indicate that the South African subspecies is distinct from other subspecies to the north, confirming that oribi in South Africa should be managed as a distinct conservation unit. Across the South African range, high genetic diversity is present with some evidence for genetic structure (phylogenetic trees and haplotype networks). However, there is no spatial component to the diversity (non-significant p-values in AMOVA analyses), possibly because of historic translocations. We evaluate translocation approaches currently in place, and make specific and general recommendations for future conservation management based on an improved understanding of population genetic diversity and genetic structure.Keywords: Bovidae, conservation management, phylogeography, spatial genetic structure, translocation

orchid-pollinator data

Interactions between orchid and pollinator species. Data from the literature. Full_database: database with 243 orchid species and 773 pollinator species. Reduced_database: database with 153 orchid species (i.e. orchid species for which phylogenetic data were available) and 726 pollinator specie