Biodiv Sci ›› 2006, Vol. 14 ›› Issue (1): 48-54.DOI: 10.1360/biodiv.050189

• 论文 • Previous Articles     Next Articles

DNA sequence variation in the mitochondrial control region of lenok (Brachymystax lenok) populations in China

Yingzhe Xia1, 2, Yan Sheng1*, Yiyu Chen3   

  1. 1 Institute of Zoology, Chinese Academy of Sciences, Beijing 100080
    2 Graduate School of the Chinese Academy of Sciences, Beijing 100049
    3 Chinese Academy of Sciences, Beijing 100864
  • Received:2005-09-06 Revised:2005-10-24 Online:2006-01-20 Published:2006-01-20
  • Contact: Yan Sheng

Abstract: Brachymystax lenok (Salmonidae) is an economically important fish species in China whose population is currently declining due to overexploitation and environmental pollution. Recently it has been listed as a threatened species in the China Red Data Book of Endangered Animals. To study the genetic structure and phylogeographic pattern of its populations is important for addressing the systematics, evolution, and effective conservation of this species. Partial sequences of the mitochondrial control region (835 bp) were obtained by PCR amplification of 71 individuals of Brachymystax lenok from seven populations in China’s eastern river systems. A total of 43 (5.1%) nucleotides were variable, resulting in a total of 15 haplotypes. Analysis of molecular variance indicated that a high proportion of the total genetic variance was attri- butable to variations among regions (63.55%), whereas 24.17% and 12.28% occurred among populations within regions and within populations, respectively. A molecular phylogenetic tree constructed using the neighbor-joining (NJ) method suggested that the 15 haplotypes were assigned to three clades associated with geographic regions. There were no shared haplotypes found among regions. The pattern of phylogenetic dis-continuity, which is associated with spatial separation, is a result of both historical (long-term, zoogeographic barriers to gene flow) and contemporary (limited dispersal and gene flow capabilities) factors. Based on these results, we propose that each of the three evolutionarily distinct groups of lenok populations should be protected from loss of biodiversity. It is highly recommended that management efforts should be focused on riv-erine conservation, avoiding translocations from the populations of different regions.