闽江水系绒螯蟹的表型性状差异与分子遗传差异的比较与分析

表型性状差异(differentiation in phenotypictraits,PST)和分子遗传差异(differentiation at neutral molecular markers,FST)是近期进化生物学的研究热点之一。闽江水系是我国中华绒螯蟹与合浦绒螯蟹的主要混杂地域,是研究绒螯蟹遗传与进化的理想地之一。为探讨闽江水系绒螯蟹的PST和FST,以2009和2010年度闽江水系的133个绒螯蟹样本为材料,进行了14个表型数量性状差异分析和6个微卫星标记的遗传差异分析。结果发现:除3个表型性状不存在显著差异外,其他表型性状在不同年份间均存在极显著差异(P<0.01);2009年绒螯蟹的平均期望杂合度极显著高于2010年绒螯蟹(P=0.008),而平均等位基因丰富度、观测杂合度和近交系数均不存在显著差异(P=0.136～0.675);年份间的平均FST为0.1429;通过对PST与FST的比较发现,除第二步足掌节长度(F2)性状外,其他表型数量性状的PST值均高于FST值,表明这些性状均受到了较明显的选择压力。该文研究结果为绒螯蟹的分子进化研究积累了资料,也为其他水产生物的PST和FST比较研究提供了参考。

Comparison and analysis between P(ST) and F(ST) of mitten crabs in the Minjiang River

Recently, differentiation in phenotypic traits (P(ST)) and differentiation at neutral molecular markers (F(ST)) across populations have been become an important topic in evolutionary biology. The Minjiang River is a key genetic introgression zone between the Chinese mitten crab (Eriocheir sinensis) and the Hepu mitten crab (Eriocheir hepuensis), making it an excellent area to study their genetics and evolutionary mechanisms. We compared and analyzed P(ST) in 14 phenotypic traits and F(ST) in six microsatellite markers from 133 individuals of the mitten crab, sampled in the Minjiang River in 2009 and 2010. The results indicated that 11 phenotypic traits were significantly different (P<0.01) between the 2009 and 2010 populations. The mean expected heterozygosity (H(E)) of the 2009 populations was significantly higher (P=0.008) than that of 2010 populations, but the mean allele richness (A(R)), observed heterozygosity (H( O)) and inbreeding coefficient (F(IS)) were all not significant between 2009 and 2010 populations (P=0.136-0.675). F(ST) in microsatellite markers was 0.1429 between the two years. In the 14 traits, only one trait (F2) was found with P(ST)F(ST), suggesting that directional selection is occurring. This study provides valuable data to the further study and analysis of the molecular evolution of the mitten crab, and contributes a useful reference in comparing P(ST) and F(ST) in other aquatic organisms.