基于线粒体COI基因比较分析野生与养殖厚壳贻贝种群的遗传多样性

Genetic Diversity Evaluation by the Comparative Analysis on Mitochondrial COⅠ Gene between Wild and Cultured Populations of Mytilus coruscus

[目的]通过比较分析线粒体CO I基因,探讨福州厚壳贻贝野生型和养殖型种群的遗传多样性。[方法]以福建省福州市野生厚壳贻贝(Mytilus coruscus Gould)和养殖厚壳贻贝各20个样本为试验材料,通过设计特异性引物,采用PCR技术对该40个个体的mtDNACO I(线粒体细胞色素氧化酶亚基Ⅰ)序列进行扩增,通过测序分析和序列比对检索,鉴定扩增的序列,并利用MEGA(version 4.10)和DnaSP(version 4.0)软件对序列进行分析。[结果]测序结果显示扩增序列总碱基数为668 bp,40条序列中T、C、A和G碱基平均含量分别为28.0%2、2.8%3、2.3%和16.9%,其中A+T的含量(60.3%)显著高于G+C含量(39.7%),表现了明显的碱基偏倚;40个个体表现为26种单倍型,包括408个多态位点,单倍型间平均遗传距离为0.299,单倍型多态性(h)为0.944,核苷酸多态性(π)值为0.153 06。上述结果表明福州厚壳贻贝的遗传多样性水平比较高,并且养殖群体和野生群体无遗传分化。[结论]该研究揭示了福州厚壳贻贝的遗传资源现状,试验结果可为厚壳贻贝良种筛选提供参考依据。

[ Objective ] To evaluate the genetic diversity of wild and cultured Mytilus coruscus through comparing their mitochondrial CO I genes. [ Method] 20 wild and 20 cultured Mytilus coruscus were collected from Fuzhou of Fujian Province. Through the design of specific prim- ers, the PCR technology was adopted to amplify the mtDNA CO I sequences of the 40 individuals. Through sequencing analysis and compari- son, the amplified sequences were identified and compared with the MEGA（ version 4.10） and DnaSP（ version 4.0） softwares. [ Resultl Se- quences length of the mtDNA CO I gene was 668 bp in 40 Mytilus coruscus individuals, and the average contents of T, C, A and G were 28.0%, 22.8% , 32.3% and 16.9%, respectively. The content of A ＋ T（63% ） was significantly higher than that of G ＋ C （39.7%）. In the 40 samples, there were 26 haplotypes and more than 408 polymorphic loci, the average genetic distance between the haplotypes was 0.299, and the haplotypic diversity （h） and nucleotide diversity （w） were 0. 944 and O. 153 06, respectively. The findings proved that the genetic diversity of the Mytilus coruscus was high and there was no genetic differentiation between wild and cultured populations. [ Conclusion ] The study exposed the genetic resources status of Mytilus coruscus and the experimental results could provide references for the screening of aood Mytilus coruscus breeds.