摘要
比较分析了钝吻黄盖鲽和尖吻黄盖鲽线粒体基因组COI、Cytb基因以及D-loop片段总长度为1 373 bp的核苷酸序列,两种间共检测到107处核苷酸替换,蛋白质编码基因上的核苷酸替代主要是第三密码子位点上的同义替换。核苷酸组成分析结果表明:3个目的片段的鸟嘌呤(G)含量普遍较低,在两个蛋白编码基因第三密码子位点上表现得尤为明显。两种黄盖鲽在线粒体基因组不同片段上存在明显的遗传分化,核苷酸替代速率最快的是D-loop,COI和Cytb核苷酸替代速率基本一致。建议在进行黄盖鲽属鱼类分子系统发育研究时,应该针对不同研究目的选择合适的分子标记。基于Cytb基因片段序列的分析结果表明:钝吻黄盖鲽和尖吻黄盖鲽两种的分岐时间约为200万年,两种间的分化事件发生在更新世(Pleistocene)。
Pleuronectes yokohama and P. herzensteini, belonged to the family Pleuronectidae, are commercially important fisheries resources in Northwest Pacific Ocean. To date, no researches were carried out in the differentiation between the two species. Partial nucleofide sequences of mitochondrial DNA COI, Cyt b genes and D-loop were sequenced and analyzed for P. yokohama and P. herzensteini in the present day. 107 nucleotide substitutions were checked between the two species in the total 1 373 bp sequences analyzed, and most of them were synonymous transitions at the third codon positions in the two proteincoding genes. Nucleotide composition analysis indicated a strong bias against guanine （G） in the three fragments, especially in the third codon positions of COI and Cyt b gene. There was obvious difference on the degree of genetic divergence between the two species in the three mtDNA segments. The substitution rate for D-loop was the highest and the rates for COI and Cyt b were generally similar. It is suggested that gene markers used in future research should be selected carefully according to the different situations. The estimated divergence time between the two Pleuronectes species based on Cyt b gene was about 2 million years, which indicated a Pleistocene divergence for the two species.
出处
《水产学报》
CAS
CSCD
北大核心
2009年第2期201-207,共7页
Journal of Fisheries of China
基金
国家“八六三”高技术研究发展计划(2006AA09Z418)
国家重点基础研究发展计划(2005CB422306)
农业部海洋渔业资源可持续利用重点实验室开放课题(实开2005-07)
关键词
钝吻黄盖鲽
尖吻黄盖鲽
线粒体DNA
核苷酸组成
分歧时间
Pleuronectes yokohama
Pleuronectes herzensteini
mtDNA
nucleofide composition
divergence time
