台湾海峡及其邻近海域黄鲫群体遗传多样性研究

摘要

本研究对采自台湾海峡及其邻近海域4个群体(宁德、平潭、厦门和漳浦)的黄鲫样品进行线粒体DNA控制区基因片段扩增,并基于此片段检测该海域黄鲫群体的遗传多样性和遗传结构。结果显示,控制区前半段存在4—7次39 bp的重复单元,5次重复所占比例最高,并随着从北向南有逐渐降低的趋势。4个黄鲫群体呈现出高的单倍型多样度和低的核苷酸多样度,遗传多样性处于较高水平。邻接关系树和单倍型网络图中并未检测到与地理群体相对应的谱系结构；基因流和确切 P检验结果显示4个黄鲫群体间可进行随机交配； AMOVA和Fst分析结果显示遗传变异主要来自于黄鲫群体内,群体间遗传分化微弱,无显著群体遗传结构。核苷酸不配对分布和中性检验结果均显示黄鲫经历了近期的群体扩张事件,推测扩张时间大约在2.5万—4.9万年前,属于更新世晚期。虽然该海域黄鲫的遗传多样性较高,但其资源量已经出现衰退的迹象,应加强相应的渔业管理措施,合理开发和利用黄鲫资源做到可持续发展。%In this study, we investigated the genetic diversity and genetic structure ofSetipinna tenuifilis populations in the Taiwan Strait and its adjacent waters. We amplified and sequenced the mitochondrial DNA control region segments by using PCR from 96 individuals of four populations (Ningde, Pingtan, Xiamen and Zhangpu). A 39-bp tandem copy was found at the 5 end of the segment and the numbers of polymorphic tandem copies were 4—7 detected in four popu-lations. The most frequency number of copies was five in all four populations, and the number decreased from northto south. High genetic diversity was detected among the four populations, along with the high haplotype diversity and the low nucleotide diversity. We did not observe the genealogical structure corresponding to sampling locations in the neighbor-joining tree and the minimum spanning network. The gene flow and the exactP test showed that theS. tenuifilis populations in the Taiwan Strait and the adjacent waters were panmictic. AMOVA and pair-wiseFstrevealed that there was no genetic differentiation or significant difference in the genetic structure between the populations. Both the mismatch distribution analysis and the neutrality tests indicated that there was a recent population expansion inS. tenuifilis, which might have occurred 25000—49000 years ago during the late Pleistocene. Despite the high genetic diversity,S. tenuifilis already showed signs of decline. More attentions should be paid on the management of fisheries in order to protect the resources ofS. tenuifilisand to maintain the sustainable development.