紫贻贝野生群体与养殖群体线粒体COⅠ基因的遗传比较分析

Genetic Diversity Evaluation on Mitochondrial COⅠ Gene between Wild and Cultured Populations of Mytilus edulis

[目的]比较紫贻贝野生群体与养殖群体线粒体COⅠ基因的遗传多样性,为其种质资源筛选提供理论依据。[方法]采集山东省乳山市野生紫贻贝(Mytilus edulis Linnaeus)和养殖紫贻贝各12个样本;通过设计特异性引物,采用PCR技术对24个个体的mtDNA COⅠ序列进行了扩增,测序得到的序列总碱基数为706 bp;采用MEGA(Version 4.0)和DnaSP(Version 4.0)软件对序列进行了分析。[结果]24条序列中T、C、A和G碱基平均含量分别为34.6%、16.7%、25.9%和22.8%,其中A+T的含量(60.5%)显著高于G+C含量(39.5%),表现了明显的碱基偏倚。24个个体表现为18种单倍型,包括568个多态位点,单倍型间平均遗传距离为0.683,单倍型多态性(h)为0.953,核苷酸多态性(π)值为0.317 69。[结论]紫贻贝的遗传多样性水平较高,且乳山养殖群体和野生群体无遗传分化。

[ ObjectiveJ The aim was to compare the genetic diversity ot mitochondrial Ut31 gene between wild and cultured populations of Mytitlus edulis in order to provide theoretical basis for the germplasm screening of Mytilus edulis. [ Method ] For evaluating the genetic diversity of Mytilus edulis ,24 individuals of Mytilus edulis were collected from Rushan City,Shandong Province. Half of them were the wild population, and the other half was the cultured population. Sequences length of the mtDNA COl gene was 706 bp in 24 Mytilus edulis individuals by PCR amplification and electrophorcsis. The sequences were analyzed by using the MEGA （Version 4.10） and DnaSP （Version 4. O） software. [ Result ] The average con- tents of T,C ,A and G were 34.6% ,16.7% ,25.9% and 22.8% ,respectively. In the 24 samples,there were 18 haplotypes,and the polymorphic sites,the average genetic distance between haplotypes,the haplotypic diversity and nucleotide diversity were 568,0. 683,0. 953 and 0. 317 69 ,re- spectively. [ Conclusion] The genetic diversity of Mytilus edulis was high,and there was no genetic differentiation between the wild and cultured populations.