摘要
通过Long-PCR技术获得哈氏仿对虾(Parapenaeopsis hardwickii)线粒体全基因组,序列长度为15922 bp,共包含13个编码蛋白基因、2个rRNA基因、22个tRNA编码基因和1个非编码的控制区。序列分析结果表明,编码蛋白基因的排列方式与泛甲壳动物线粒体基因组的原始排列完全一致,nad2基因的变异程度最高,而cox2基因最为保守。利用16S rRNA和COI基因序列进行了群体遗传多样性分析和系统进化分析。16S rRNA基因共检测出1种单倍型,不存在多态性位点;COI基因共检测出7种单倍型,6个多态性位点。COI基因片段比16S rRNA基因片段变异丰富,更适于哈氏仿对虾种群的遗传多样性分析。基于16S rRNA和COI基因片段的系统进化分析结果不一致,结合形态学分析表明,哈氏仿对虾是仿对虾属独立的分支,与细巧仿对虾(Parapenaeopsis tenella)和亨氏仿对虾(Parapenaeopsis hungerfordi)亲缘关系较近。根据COI基因片段的遗传距离推测出仿对虾属的大致分化时间发生在中新世末期至上新世早期。
The complete sequence of mitochondrial genome of the sword prawn Parapenaeopsis hardwickii was determined using long-PCR, which was 15,922 bp in length and encoded the standard set of 13 protein-coding genes, 2 rRNAs, 22 tRNAs, and a non-coding region. Sequence analysis of the mitochondrial genome showed that the order of the protein-coding genes retained as the pancrustacean ground pattern. Among the protein-coding genes, nad2 and cox2 exhibited the most and least variance, respectively. Based on the sequences of 16 S rRNA and COI gene, we investigated genetic diversity of the wild population of P. hardwickii and its phylogenetic relationship with other members of the genus Parapenaeopsis. One haplotype and no polymorphic sites were detected in 16 S rRNA sequences, while 7 haplotypes and 6 polymorphic sites were in CO Ⅰ sequences, including 5 singleton variable sites and 1 parsimony informative sites. The variations in COⅠ sequences were more than that in 16 S rRNA sequences, showing that COⅠwas adaptive for genetic diversity analysis in P. hardwickii.
引文