中国文昌鱼系统分类的线粒体COI和Cyt b基因片段分析(英文)

Phylogenetic separation of lancelets in China revealed by mitochondrial COI and Cyt b gene analysis

白氏文昌鱼Branchiostoma belcheri(Gray)在我国和日本沿海均有分布,一般认为分布于青岛和日本沿海的文昌鱼为白氏文昌鱼的一个亚种(B.belcheri tsingtauense),分布于厦门地区的文昌鱼为白氏文昌鱼。该文测定了厦门海域和青岛海域的文昌鱼mtDNA COI和Cyt b基因的部分序列,并与日本产的文昌鱼以及产于大西洋的几种文昌鱼进行了比较。基于COI和Cyt b基因序列的分析结果表明,厦门文昌鱼和青岛文昌鱼之间的平均遗传距离是18.8%和20.3%,远远超过了在其他物种中观察到的种内差异,已达到种间差异水平,而日本文昌鱼和青岛文昌鱼的遗传距离分别为1.3%和0.9%,应属于种内差异。该文研究结果支持厦门文昌鱼和青岛文昌鱼为不同种的观点。

The amphioxus distributes along the east coast of China from Xiamen waters to Bohai Sea and Japanese waters. It is commonly accepted that amphioxus in both Bohai Sea and Japanese waters belong to Branchiostoma belcheri tsingtauense, a subspecies of B. belcheri, according to the previous survey on the morphological characteristics. Nevertheless, the genetic distance between Xiamen amphioxus and Qingdao amphioxus averages 18.8% and 20. 3% based on partial sequence analysis of COI and Cyt b gene, which is much higher than that is observed in other intraspecific variations in the present paper. The values between Japanese amphioxus and Qingdao amphioxus are only 1.3% and 0.9% based on partial sequence analysis of COI and Cyt b gene, which indicates both of them should belong to the same species. Above all, our results support the viewpoint that amphioxus in Qingdao and Xiamen might belong to different species and the original subspecies B. belcheri tsingtauense should be renamed as a separate species and its new scientific name should be B. tsingtauense.