Phylogeny and genetic structure of the goitered gazelle (Artiodactyla,Bovidae) in north-western China indicated by the hypervariable mitochondrial control region

The goitered gazelle, Gazella subgutturosa, is a medium-sized ungulate inhabiting arid and semi-arid regions in the Middle East and central Asia. The intraspecific classification of the species remains unclear. We analysed the genetic diversity in mitochondrial DNA control region (CR) sequences (976?bp) from 104 wild samples from the Xinjiang Uyghur Autonomous Region (XUAR) in north-west China, and reconstructed phylogeny with additional sequences from across the species’ range. We detected 58 haplotypes in XUAR populations, all but three of which were specific to single sampling sites. The phylogenetic analysis displayed two obvious clades of mtDNA haplotypes and the other haplotypes differed from the two clades. A median-joining network showed three groups of haplotypes were to a high extent concordant with the phylogenetic tree. The haplotype clustering was consistent with their geographic distribution. Nei’s net sequence divergences amongst the three groups ranged from 0.010 to 0.018 and indicated three subspecies, two of which inhabit XUAR. We detected strong differentiation between northern (NX) and southern (SX) XUAR populations overall (F_ST?=?0.4448, P?相似文献   

Origin and evolution of the major histocompatibility complex class I region in eutherian mammals

Major histocompatibility complex (MHC) genes in vertebrates are vital in defending against pathogenic infections. To gain new insights into the evolution of MHC Class I (MHCI) genes and test competing hypotheses on the origin of the MHCI region in eutherian mammals, we studied available genome assemblies of nine species in Afrotheria, Xenarthra, and Laurasiatheria, and successfully characterized the MHCI region in six species. The following numbers of putatively functional genes were detected: in the elephant, four, one, and eight in the extended class I region, and κ and β duplication blocks, respectively; in the tenrec, one in the κ duplication block; and in the four bat species, one or two in the β duplication block. Our results indicate that MHCI genes in the κ and β duplication blocks may have originated in the common ancestor of eutherian mammals. In the elephant, tenrec, and all four bats, some MHCI genes occurred outside the MHCI region, suggesting that eutherians may have a more complex MHCI genomic organization than previously thought. Bat‐specific three‐ or five‐amino‐acid insertions were detected in the MHCI α1 domain in all four bats studied, suggesting that pathogen defense in bats relies on MHCIs having a wider peptide‐binding groove, as previously assayed by a bat MHCI gene with a three‐amino‐acid insertion showing a larger peptide repertoire than in other mammals. Our study adds to knowledge on the diversity of eutherian MHCI genes, which may have been shaped in a taxon‐specific manner.