褶皱臂尾轮虫微卫星的分离和遗传多样性分析

Isolation of Microsatellites of Brachionus Plicatilis and Determination of Genetic Diversity of A Culturing Population

褶皱臂尾轮虫（Brachionus plicatilis）是轮虫动物门（Rotifera）中的广盐种。其个体微小、培养容易、营养丰富，是目前唯一能够在海水养殖中进行大规模培养，并用于海产动物人工育苗的物种。褶皱臂尾轮虫生活史为孤雌生殖和有性生殖世代交替进行，是生物学研究的模型生物。本研究用FIAs—C0法构建了褶皱臂尾轮虫微卫星富集文库，分离了135个微卫星；用PCR-PAGE分型法分析山东半岛褶皱臂尾轮虫群体，获得8个多态微卫星。等位基因数2～4个；观测杂合度和期望杂合度范围分别为0．1471～0．6364和0．3139～0．6559；遗传偏离指数为一0．3624～0．05353；多态信息含量为0．2615～0．5841。无微卫星偏离哈温平衡，但有2个微卫星处于连锁不平衡。本研究筛选的8个微卫星为褶皱臂尾轮虫遗传多样性和种群结构分析提供了标记。

Brachionus plicatilis, a euryhaline species of the Rotifera, is widely distributed in both fresh- water and marine environments. The high caloric value, small size and relative ease of mass culture have all served to make B. plicatilis the only artificial breeding species in the field of large-scale mari- culture as a kind of important nursery bait. The life history of B. plicatili is comprised of two alterna- tions of generations, parthenogenesis and sexual reproduction, which make them an ideal model for bio- logical studies. In this study, a microsatellite enriching library of B. plicatilis was constructed with FIASCO method. In total, 135 microsatellites were obtained and used to determine the genetic diversi- ties of a cultured B. plicatilis population. Eight microsatellites were found to be polymorphic. The number of alleles per locus ranged from 2 to 4. The observed and expected heterozygositied ranged from 0. 1471 to 0. 6364 and from 0. 3139 to 0. 6559, respectively. The genetic deviation indies and polymor- phism information contents ranged from 0. 3624 to 0. 05353 and 0. 2615 to 0. 5841, respectively. No polymorphic locus deviated from Hardy Weinberg equilibriums and two loci were in linkage disequilibriums. The microsatellites developed in this study will facilitate the genetic diversity evaluation of B. plicatilis.