中国北鳅谱系地理学分析

北鳅(Lefua costata)为冷水性鱼类,分布于淮河以北,分析遗传结构能够反映其适应环境变迁的响应.基于线粒体D-loop区211条序列分析了我国北鳅的谱系地理学和遗传多样性,样本采自9条水系共18个样点.单倍型分析显示共计55个单倍型,呈高单倍型多样性(h=0.9304)和高核苷酸多样性(π=0.0087).单...

PHYLOGEOGRAPHY OF LEFUA COSTATA IN CHINA

Lefua costata is a primary freshwater fish confining to cold areas in north of the Huai River.They are the suited model for zoogeographic studies for their high environmental dependence.Here,based on D-loop mtDNA gene,the genetic diversity and phylogeography of L.costata were analyzed on the basis of 211 specimens from 18 sampling in 9 basins in north-eastern China.55 haplotypes were identified,high haplotype diversity(h=0.9304)and nucleotide diversity(π=0.0087)were detected.Haplotype diversity and nucleotide diversity of population in Liaodong Peninsula(LD)were the highest(h=0.8920,π=0.0074),and the farther away from the Liaodong Peninsula,the lower haplotype diversity of the population.The analysis of molecular variance(AMOVA),pairwise comparisons of genetic distance(K2P)and genetic differentiation index(FST)among the populations showed that the genetic differentiation between the LD population and other populations were highly significant.Phylogenetic analyses based on ML and BI methods indicated all haplotypes from the 9 basins were not clustered separated but mixed with each other according to the geographical distribution.Network analysis showed that all haplotypes were divided into three branches:LD population was clustered in branch A;Huai-Huang River population(HH)and Hai-Luan River population(HL)were clustered in branch C;branch B contained all geographic populations.Neutral test and mismatch analysis showed that overall L.costata population experienced population expansion.According to the average evolution rate(1.00%Ma)and fossil calibration point,the divergence time of the populations of L.costata was 0.0477—2.3784 Ma.The earliest divergence time between LD population and other populations was about 2.3784 Ma,and it was speculated that the Liaodong Peninsula is one of the origin center of L.costata and little affected by Quaternary glaciation,other population had been experienced multiple gene exchange through the Huangbohai Plain estuary and the Songliao Ancient Great Lake.