生物多样性 ›› 2010, Vol. 18 ›› Issue (3): 262-274.DOI: 10.3724/SP.J.1003.2010.262

• 论文 • 上一篇    下一篇

中国黄颡鱼的线粒体DNA多样性及其分子系统学

库喜英1,2; 周传江1,3; 何舜平1*   

  1. 1 中国科学院水生生物研究所, 武汉 430072
    2 中国科学院研究生院, 北京 100049
    3 西南大学生命科学学院, 重庆 400715
  • 收稿日期:2009-10-29 出版日期:2010-05-20 发布日期:2012-02-08
  • 通讯作者: 何舜平

Validity of Pseudobagrus sinensis and mitochondrial DNA diversity of Pseudobagrus fulvidraco populations in China

Xiying Ku1,2; Chuanjiang Zhou1,3; Shunping He1*   

  1. 1 Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072

    2 Graduate University of the Chinese Academy of Sciences, Beijing 100049

    3 School of Life Science, Southwest University, Chongqing 400715
  • Received:2009-10-29 Online:2010-05-20 Published:2012-02-08
  • Contact: Shunping He

摘要:

基于体侧色斑、背鳍前部形态、吻长及尾柄长的差异, Ng和Kottelat(2007)将分布于中国的黄颡鱼群体划为两个物种: 北方群体为Pseudobagrus sinensis, 南方群体为P. fulvidraco。本研究通过对70个黄颡鱼标本相关形态特征的测量及对线粒体cyt b基因序列的分析, 探讨了P. sinensis物种的有效性问题。结果表明: 依据体侧色斑和背鳍前部形态的差异, 可将黄颡鱼分为对应于P. sinensisP. fulvidraco的两种形态类型, 但对尾柄长、吻长的测量发现二者没有差异。对70条cyt b基因序列的分析结果为: 两种鱼类有1个共同的单倍型; 两种鱼类的单系性在系统发育分析中都没有得到重现, 而二者聚在一起形成获得100%支持率的单系群; 两种鱼类群体之间存在持续的基因交流(Nm = 4.7); 两种鱼类在单倍型的巢式支系分析(nested clade analysis, NCA)中没有形成各自独立的进化谱系, 所有的单倍型以不超过5步的突变全部被纳入同一个进化网络中。因此我们认为P. sinensis不是有效物种, 而应被视为黄颡鱼的一种形态类型。基于cyt b基因的序列变异, 本研究对黄颡鱼群体的遗传多样性和种群结构作了初步分析。群体的核苷酸不配对分布及Tajima’s D中性检验表明, 约在10.1–14.1万年前, 黄颡鱼在其分布范围内经历过群体扩张, 推测这可能是导致黄颡鱼群体单倍型多样度高(h = 0.857 ± 0.0014)而核苷酸多样度低(π = 0.0023 ± 0.0003)的主要原因。此外, 分析结果显示黄颡鱼群体缺乏明显的地理结构, 推测原因可能是历史上水系的连通促进了不同地理群体之间的基因交流。

Abstract:

Based on the differences in caudal peduncle, snout length, predorsal profile and the lateral color pattern, Ng & Kottelat (2007) supposed that the currently recognized Pseudobagrus fulvidraco represent at least two distinct species, P. sinensis from northern China and P. fulvidraco from southern China. We examined the forenamed morphologic characters and sequenced the cytochrome b gene segments of 70 specimens to test the validity of P. sinensis. We found the differences in predorsal profile and the lateral color pattern do not occur together with the differences in caudal peduncle and snout length. Results of molecular phylogenetic and population genetic analyses were: (1) the most common haplotype detected was shared by P. sinensis and P. fulvidraco; (2) the reciprocal monophyly of both species was not confirmed whereas all samples of the two species were grouped in a monophyletic cluster with 100% bootstrap support; (3) gene flow is ongoing between populations of P. sinensis and P. fulvidraco (Nm = 4.7); and (4) the haplotype network did not detect any disjoint groups corresponding to the two species. We thus speculate that P. sinensis is not valid species but probably a synonym of P. fulvidraco. Low genetic divergence was detected among P. fulvidraco populations of China’s main river drainages, which was supposed to be resulted from a recent population expansion that occurred about 101,000–141,000 years ago. No significant geological architecture was detected from Chinese populations of P. fulvidraco and the historical river connection might have promoted the gene exchange among different geological populations.