脊尾白虾（Exopalaemon carinicauda）3个野生群体mtDNA 16S rRNA序列差异及长臂虾科系统进化关系

摘要

Using PCR amplification and sequencing analysis, we examined the 16S rRNA gene in the mitochondrial gene of total 58 individuals that belonged to three wild populations of Exopalaemon carinicauda, which were sampled in the Haizhou, the Xiangshan, and the Laizhou Bays. 16S rRNA fragments that had 509bp were obtained in our study. Through comparing the variation sites, nucleotide diversity and average number of nucleotide differences were calculated to analyze the gene sequence variation and genetic diversity. The results showed that the colonies from the Haizhou and the Laizhou Bays had lower levels of genetic diversity than that from the Xiangshan Bay. Fst values between the Xiangshan and the Laizhou Bays showed significant genetic differences, and Fst values among all the other populations showed no strong genetic differences. The molecular phylogenetic tree was constructed using the NJ method to study molecular phylogeny of several species of Palaemonidae. Our finding indicated that the Phylogenetic tree clustered into two branches： Palaemoninae clustered into one branch, and Pontoniinae clustered into the other. In addition, differentiation time of 12 species of the Palaemonidae was deduced base on the percentage of the 16S rRNA divergence.%采用PCR扩增和序列测定等技术,对脊尾白虾3个野生群体共计58个个体的线粒体16SrRNA基因片段进行初步研究。结果表明,在获得的长度为509bp核苷酸序列中,共检测到7个变异位点、8种单倍型,除象山湾群体外其它两个群体遗传多样性水平都较低。AMOVA分析表明,象山湾与莱州湾群体有显著的遗传差异,其余群体间的遗传差异不显著。另外,将本研究所得序列与GenBank中长臂虾科11个种的16SrRNA基因片段序列进行比较后,发现其聚类关系与传统分类略有不同,并依据16SrRNA序列变异百分比推测了长臂虾科12个种的大致分化时间。