Orogenesis of the Qinghai-Tibetan Plateau, which occurred in a stepwise manner, contributed to the extreme aridity of the Tarim Basin, resulting in vulnerable and unstable ecosystems. Quaternary climatic oscillations may have affected the ecosystems and, consequently, the distributions and genetic structuring of the Tarim Basin's biota. We used nucleotide sequence data from 2 mitochondrial (mt) DNA genes (Cyt b and the D-loop) to test hypotheses associated with the matrilineal and demographical histories of the Tarim Basin's endemic Yarkand hare (Lepus yarkandensis). Range-wide sampling involving 20 populations and 224 individuals detected 126 haplotypes that clustered into 5 major lineages in both the phylogenetic tree and median-joining network. Populations from the northern and eastern Tarim Basin shared a similar history, as did those from the western and southern regions. Demographical analysis and genetic diversity estimations suggested that the western and southern regions might have served as glacial refugia for the Yarkand hare during Quaternary climatic oscillations. The distribution of the Yarkand hare, especially in the northern and eastern parts, probably represented 3 postglacial colonization events, dated to 0.21, 0.090 and 0.054 MYA, which corresponded to known interglacial periods. Given the relatively complete geographic isolation between the eastern and southern populations, the Yarkand hare likely dispersed during postglacial periods from the southwest to the north, and then onward to the east. The absence of water likely forced the species into refugia, and this differed from other Pleistocene biogeographical drivers. The demographical and historical patterns have important implications for conservation. Chinese Sci Bull, 2011, 56: 1370−1382, doi: 10.1007 Pleistocene climatic changes imposed significant range shifts on many Palearctic biota, and contributed to their demographic history and genetic diversity [1]. Many temperate species existed only in refugia at times of glacial maxima, and recolonized or expanded into newly available habitats during interglacial periods [2,3]. Quaternary evolutionary histories of European and North American biota *These authors contributed equally to this work †Corresponding authors

BackgroundUyghurs are one of the many populations of Central Eurasia that is considered to be genetically related to Eastern and Western Eurasian populations. However, there are some different opinions on the relative importance of the degree of Eastern and Western Eurasian genetic influence. In addition, the genetic diversity of the Uyghur in different geographic locations has not been clearly studied.ResultsIn this study, we are the first to report on the DNA polymorphism of cytochrome B in the Uyghur population located in Xinjiang in northwest China. We observed a total of 102 mutant sites in the 240 samples that were studied. The average number of mutated nucleotides in the samples was 5.126. A total of 93 different haplotypes were observed. The gene diversity and discrimination power were 0.9480 and 0.9440, respectively. There were founder and bottleneck haplotypes observed in Xinjiang Uyghurs. Xinjiang Uyghurs are more genetically related to Chinese population in genetics than to Caucasians. Moreover, there was genetic diversity between Uyghurs from the southern and northern regions. There was significance in genetic distance between the southern Xinjiang Uyghurs and Chinese population, but not between the northern Xinjiang Uyghurs and Chinese. The European vs. East Asian contribution to the ten regional Uyghur groups varies among the groups and the European contribution to the Uyghur increases from north to south geographically.ConclusionThis study is the first report on DNA polymorphisms of cytochrome B in the Uyghur population. The study also further confirms that there are significant genetic differences among the Uyghurs in different geographical locations.

To evaluate the utility of Y-STR data for DNA testing in two ethnic populations of Xinjiang province, a sample of 338 subjects (121 Kazakhs and 217 Uighurs) was tested. In the Kazakh and Uighur populations, the haplotype diversity was 0.868 and 0.996, respectively, and the discrimination capacity was 0.5950 and 0.8940, respectively. High numbers of singleton haplotypes were observed among Xinjiang Uighurs, but fewer were found in Kazakhs. Our results were also compared with geographically and linguistically close populations.

Lepus capensis pamirensis is a specific cape hare species that is only distributed in the Pamirs, with a cruel natural environment. The complete mitochondrial genome of the cape hare L. c. pamirensis was first determined (accession number LC073697), in a total length of 17 597 nucleotides, of which 15 310 nucleotides are coding DNA and 2287 nucleotides are non-coding DNA. It has the common feature with those of other hares with respect to genome structure and gene arrangement. It contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer tRNA genes and 1 control region (D-loop region). The complete mitochondrial genome of the cape hare L. c. pamirensis provides an important data set for further study on its classification.

Background The Yarkand hare (Lepus yarkandensis Günther, 1875) is endemic to oasis and desert areas around the Tarim Basin in the Xinjiang Uyghur Autonomous Region of northwest China; however, genome-wide information for this species remains limited. Moreover, the genetic variation, genetic structure, and phylogenetic relationships of Yarkand hare from the plateau mountain regions have not been reported. Thus, we used specific-length amplified fragment sequencing (SLAF-seq) technology to evaluate the genetic diversity of 76 Yarkand hares from seven geographic populations in the northern and southwestern parts of the Tarim Basin to investigate single-nucleotide polymorphism (SNP) marker-based population differentiation and evolutionary processes. Selective sweep analysis was conducted to identify genetic differences between populations. Results Using SLAF-seq, a total of 1,835,504 SNPs were initially obtained, of which 308,942 high-confidence SNPs were selected for further analysis. Yarkand hares exhibited a relatively high degree of genetic diversity at the SNP level. Based on pairwise FST estimates, the north and southwest groups showed a moderate level of genetic differentiation. Phylogenetic tree and population structure analyses demonstrated evident systematic phylogeographical structure patterns consistent with the geographical distribution of the hares. Hierarchical analysis of molecular variation further indicated that genetic variation was mainly observed within populations. Low to moderate genetic differentiation also occurred among populations despite a common genomic background, likely due to geographical barriers, genetic drift, and differential selection pressure of distinct environments. Nevertheless, the observed lineage-mixing pattern, as indicated by the evolutionary tree, principal component analysis, population structure, and TreeMix analyses, suggests a certain degree of gene flow between the north and southwest groups. This may be related to the migration of hares to high-altitude water sources southwest of the basin during glacial climatic oscillations, as well as river re-diffusion and oasis restoration in the basin following the glacial period. We also identified candidate genes, and their associated gene ontology terms and pathways, related to the adaptation of Yarkand hares to different environmental habitats. Conclusions The identified genome-wide SNPs, genetic diversity, and population structure of Yarkand hares expand our understanding of the genetic background of this endemic species and provide valuable insights into its environmental adaptation, allowing for further exploration of the underlying mechanisms.

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Lepus yarkandensis is a national second-class protected animal endemic to China and distributed only in the hot and arid Tarim Basin in Xinjiang. We sequenced and described the complete mitogenome of L. yarkandensis to analyze its characteristics and phylogeny. The species’ DNA is a 17,047 bp circular molecule that includes 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes, and one control region. The overall base composition was as follows: A, 31.50%; T, 29.40%; G, 13.30% and C, 25.80%, with a high A+T bias of 60.9%. In the PCGs, ND6 had deviation ranges for AT skew (–0.303) and GC skew (0.636). The Ka/Ks values of ND1 (1.067) and ND6 (1.352) genes were >1, indicating positive selection, which might play an important role in the adaptation of L. yarkandensis to arid and hot environments. The conserved sequence block, the central conserved domain, and the extended termination-associated sequences of the control region and their features were identified and described. The phylogenetic tree based on the complete mitogenome showed that L. yarkandensis was closely related to the sympatric Lepus tibetanus pamirensis. These novel datasets of L. yarkandensis can supply basic data for phylogenetic studies of Lepus spp., apart from providing essential and important resource for further genetic research and the protection of this species.

Lepus tolai has a wide geographic distribution in the world, and there are some taxonomic confusions due to lack of studies. The complete mitochondrial genome of L. tolai in Xinjiang is 17,047 bp long with 13 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and a control region. The overall base composition is 31.81% of A, 29.40% of T, 25.67%of C, and 13.12% of G, showing AT-rich. Phylogenetic analysis results showed that L. tolai is closely related to Lepus timidus, and distantly related to Lepus earoupenses and Lepus capensis. The new mtDNA data will supplement the mitochondrial gene pool of Lepus and helpful for validating taxonomic status of L. tolai on mtDNA level.