新疆卡拉麦里山有蹄类自然保护区鹅喉羚遗传多样性及系统发育地位

Genetic diversity and phylogenetic status of Gazella subgutturosa at the Mountain Kalamaili Ungulate Nature Reserve,Xinjiang

鹅喉羚是生活于亚欧大陆荒漠、半荒漠地区重要的有蹄类动物。2010年春季,新疆卡拉麦里山有蹄类自然保护区遭遇了60年不遇的雪灾,我们采集了野外救灾发现的130头死亡鹅喉羚肌肉样本,采用PCR和测序技术,研究了鹅喉羚线粒体DNA的Cyt b基因1143 bp核酸序列,发现新疆卡拉麦里山有蹄类自然保护区生存的鹅喉羚单倍型多样性较高(Hd=0.855),核苷酸多样性较低(π=0.002 24)。采用邻接法(NJ)、最大似然法(ML)构建单倍型之间的系统发育树,以及network所构建的单倍型间中介网络图都显示出2个遗传分化程度很大的分支,且这2个分支都出现过明显的群体扩张和持续增长。将本研究获得的单倍型H1与Genebank检索获得的瞪羚属其他12个物种Cyt b基因进行了比较,分别采用邻接法(NJ)和最大似然法(ML)构建分子系统树,证明与鹅喉羚最接近的物种为印度瞪羚(Gazella bennettii),鹅喉羚与瞪羚属内物种的分歧时间大约为1.08-2.5 Mya。

Goitered gazelle（ Gazella subgutturosa） is an important desert ungulates species and mainly lives in the desert and semi-desert of Eurasian areas. It was listed as a class II protected species in China. The International Union for Conservation of Nature and Natural Resources listed it as vulnerable（ VU）. In the spring 2010,many goitered gazelles were frozen,hungry and sick to death because of a snow disaster unlike any that happened in past 60 years at the Mt. Kalamaili Ungulate Nature Reserve. We sampled muscle tissue of 130 dead goitered gazelles when we participated in disaster relief in the field. The 102 cytochrome b（ Cyt b） gene sequences of goitered gazelles were sequenced and analyzed. The results indicated a high haplotypic（ H = 0. 855） and relatively low nucleotide diversity（ π = 0. 002 24） of Gazella subgutturosa at Mt. Kalamaili. Both haplotype network and phylogenetic tree based on the neighbour-joining and Maximum Likelihood methods showed two clades,suggesting a high degree of genetic differentiation. These two branches had undergone population expansion and sustainable growth. Combined with other 12 Gazella Cyt b entire sequences cited in Gen Bank,the phylogenetic trees of Gazella were reconstructed by neighbor-joining（ NJ） and Maximum-likelihood（ ML） methods,using Procapra przewalskii and Saiga tatarica as outgroup. The phylogenetic trees constructed by multiple methods（ NJ and ML）proved that Gazella bennettii is the nearest species to Gazella subgutturosa. In addition,the divergence times between Gazella and Gazella subgutturosa were estimated as 1. 08- 2. 5 Mya according to the Cyt b molecular clock.