基于线粒体Cyt b DNA阿拉善马鹿分子系统学研究

Molecular Phylogenetics of the Alashan Red Deer (Cervus elaphus alxaicus) Based on Cyt b DNA

阿拉善马鹿为国家Ⅱ级重点保护野生动物,仅分布于宁夏和内蒙古交界的贺兰山中段,是我国唯一幸存的该亚种的有效种群。目前关于野生阿拉善马鹿的分子研究尚属空白,本研究于2016年8—9月和2017年2—3月在贺兰山采集新鲜阿拉善马鹿粪便样本396份,使用线粒体Cyt b区DNA引物对提取的DNA进行物种鉴定和9对微卫星引物对其个体识别,共鉴定出278个阿拉善马鹿个体,基于线粒体Cyt b DNA对其全序列进行分析。使用线粒体Cyt b区引物对提取的粪便DNA扩增,获得了1 075 bp的序列,检测到10个变异位点,并定义了10个单倍型。其中10个变异位点占分析长度的0. 93%,均为碱基代换,无碱基插入和缺失。其单倍型多样性为0. 243,核苷酸多样性为0. 000 32。中性检验Tajima's D值为显著负值,Fu和Li's D值为不显著的负值,表示阿拉善马鹿可能经历瓶颈事件并随后出现种群扩张。在系统发育树中,阿拉善马鹿单独聚成一支且与东北马鹿亲缘关系较近,与其他中国马鹿亚种亲缘关系较远。本研究表明野生阿拉善马鹿种群总体遗传多样性较低,建议加强对该亚种的保护力度。

Cervus elaphus alxaicus is a second-class state key protected subspecies in China.It occupies only the middle region of the Helan Mountains between Ningxia and Inner Mongolia.We collected 396 fecal samples at Helan Mountains from August to September 2016 and February to March 2017.We confirmed 278 individuals of C.e.alxaicus by Cyt b sequence analysis and 9 microsatellite loci.We obtained a total of 1 075 bp fragments of Cyt b,detected 10 variable sites,and identified 10 haplotypes.The 10 variable sites accounted for 0.93%of the analysis length,all of which were base substitutions,without base insertion or deletion.The haplotype diversity was 0.243,and the nucleotide diversity was 0.000 32.Estimates of Tajima s D were significantly negative,and the Fu and Li index D was not significantly negative,meaning that the population could experience bottleneck and subsequent population expansion.In the phylogenetic tree,C.e.alxaicus was isolated into one branch and was closely related to C.e.xanthopygus,but was distantly related to other Chinese red deer subspecies.We conclude that the genetic diversity of C.e.alxaicus was low.We recommend that protection for this subspecies be strengthened.