新疆蟾蜍的遗传变异与地理分化  

Genetic Variation and Geographical Differentiation of Toad in Xinjiang

作　　者：叶小芳[1] 吕雪峰 袁亮[1] 王秀玲[1] 季荣[1] 

机构地区：[1]新疆特殊环境物种保护与调控生物学实验室中亚区域跨境有害生物联合控制国际研究中心新疆师范大学生命科学学院,新疆乌鲁木齐830054 [2]新疆畜牧科学院畜牧业质量标准研究所,新疆乌鲁木齐830000

出　　处：《干旱区研究》2017年第6期1380-1387,共8页Arid Zone Research

基　　金：新疆地方公派出国留学成组配套项目(XJDF201327);新疆青年科技创新人才培养工程项目(2014731005);新疆特殊环境物种多样性应用与调控实验室资助

摘　　要：分布在新疆境内的蟾蜍在长期适应性进化中,其表型差异较大。为了解新疆蟾蜍的遗传多样性和系统发育关系,采集了新疆26个地区254只蟾蜍,对其线粒体Cytb基因进行了扩增和测序,得到长度为880 bp的片段序列,群体单倍型多样度为0.900,核苷酸多样性为0.005 5,遗传分化指数Fst为0.695 61,基因流Nm为0.35,254条序列共定义了55种单倍型,其中H23、H15是群体共享最多的单倍型,分子变异分析(AMOVA)发现,种群间遗传变异为68.55%,种群内遗传变异为31.45%。26个地理种群中乌苏群体和尉犁群体发生过种群扩张事件,扩张时间约为10~22万年前。群体间遗传距离较小,与地理距离呈低度正相关,系统发育树显示55种单倍型分为2个支系。新疆蟾蜍具有丰富的遗传多样性,群体间的遗传分化很大,各地种群间的基因流较小,遗传变异主要来自于种群间,而非种群内,单倍型H23、H15可认为是新疆蟾蜍的原始单倍型,天山在各地理群体之间不但起屏障作用,在冰期还提供了避难场所。In a long-term adaptive evolution,the phenotypes of toad in Xinjiang are quite different. This research was to clarify the genetic diversity and phylogeny of toad in Xinjiang. The 254 toad individuals were collected from26 places in Xinjiang. The mitochondrial Cytb gene was amplified and sequenced. The results showed that 880-bp fragment sequences were obtained. The population haplotype diversity,nucleotide diversity（Pi）,fixed coefficient（Fst） and gene flow（Nm） were 0. 900,0. 005 5,0. 695 61 and 0. 35 respectively. 55 haplotypes were defined among the 254 gene sequences. Among them,H23 and H15 were the most haplotypes that shared by groups. The AMOVA molecular variation analysis revealed that the genetic variations among and within the populations were68. 55% and 31. 45% respectively. In the 26 populations,population expansion events occurred in WS and YL and before 100 000-220 000 years. Genetic distance between the populations was short. Weak positive correlation between genetic distance and geographic distance was observed. Phylogenetic tree showed that 55 haplotypes could be divided into two branches. Results indicated that there was a high genetic diversity of toad in Xinjiang. The genetic differentiation among the populations was very high,and the gene flow among the different geographic populations was low. Genetic variation was mainly derived from the situation between the populations rather than within the populations. H23 and H15 may be the original haploid types of toad. The 26 populations belong to the same species. The Tianshan Mountains not only played a role of barrier between the geographic populations,but was also a refuge during the ice age.

关 键 词：蟾蜍 遗传变异 系统发育 地理分化 CYTB 新疆 

分 类 号：Q953[生物学—动物学]