凡纳滨对虾繁殖中不同亲本对子代遗传贡献率的差异

利用5个含有稀有等位基因的高度多态性微卫星位点比较了凡纳滨对虾繁殖中不同亲本对子代遗传贡献率的差异。通过稀有等位基因的5个微卫星位点能够对亲代和子代的谱系进行明确的鉴别。10个亲代个体中有8个个体对子代群体的基因库有贡献,不同个体之间的贡献率存在差别,最高为54.28%,最低为8.57%。在亲代和子代群体遗传结构的分析中,子代等位基因的数目与亲代相比降低了11.11%。子代的平均期望杂合度(He)、平均观测杂合度(Ho)和平均多态性信息含量(PIC)等指标均低于亲代。实验结果表明:亲本对子代基因库的贡献率的差异也是造成子代群体遗传变异水平降低的原因之一;微卫星标记可作为一种有效的工具用于对虾系谱的确认、人工繁育群体遗传多样性水平的监测等方面

Difference of parental contributions in the reproduction of Pacific white shrimp Litopenaeus vannamei

The difference between parents contributing to reproduction was detected using five hyper-variable microsatellite DNA loci with unique alleles. Parentage of offspring in a stock of cultured Pacific white shrimp Litopenaeus vannamei was unambiguously determined using these five loci. Only eight of ten parents actually contributed to the production of offspring tested in this experiment. Different individuals showed large variance in parental contributions. The highest and the lowest parental contributions were 54.28% and 8.57%, respectively. The number of alleles per locus in the offspring was lower(11.11%) than that of their parents. The average heterozygosity of offspring and polymorphic information content(PIC)etc were lower than those of their parents. In this study, the difference of parental contributing to reproduction is one of the reasons for loss of genetic variability in hatchery populations. Microsatellite markers with rare alleles were effective tool for unambiguous parentage determination and estimation of genetic diversity in hatchery populations of Pacific white shrimp