湖北钉螺指名亚种一输入性扩散事件的群体遗传学

Study on the imported-diffusion event of the Oncomelania hupensis hupensis by population genetics method

2017年南昌市滨江公园赣江江滩发现大面积钉螺滋生,此为市区内首次。为追溯该种群的输入来源,本研究根据湖北钉螺采样点的地理分布进行分组,测定湖北钉螺线粒体12S rRNA、16S rRNA及CO1基因,并结合GenBank数据库中已上传序列,统计分析遗传分化系数(Fst)、基因流(Nm)等群体遗传学参数,构建单倍型网络图。基于CO1基因及12S rRNA、16S rRNA、CO1三者联合基因的结果表明来自滨江公园的湖北钉螺种群与来自武汉的湖北钉螺种群遗传背景相似;但和12S rRNA、16S rRNA基因单独分析的结果存在差异可能由于其组内样本量较少导致。各基因构建的单倍型网络图均显示:湖北钉螺滨江公园种群与武汉种群的单倍型间有直接演化关系。本研究从分子种群遗传学层面初步证实了“南昌市滨江公园输入性湖北钉螺群体可能由移栽自武汉市黄陂区的景观芦苇携带而来”的流行病学调查结果,同时表明线粒体CO1基因能够提供较丰富的信息以追溯湖北钉螺未知群体的来源。

In 2017,a large population of Oncomelania hupensis was found for the first time on the beach of Ganjiang River in Binjiang Park of Nanchang City.To trace the input source of this population,the mitochondrial 12S rRNA,16S rRNA and COI genes were determined according to the geographical distribution of the sampling sites.Furthermore,the uploaded sequences in GenBank database were combined.The population genetic parameters such as genetic differentiation coefficient(Fst)and gene flow(Nm)were statistically analyzed,and the haplotype network map was constructed.The results based on the COI gene and the combined genes of 12S rRNA,16S rRNA and COI showed that the genetic background of Binjiang population was similar to that from Huangpi District,Wuhan City.These results were different from those of 12S rRNA and 16S rRNA gene which were separately analyzed;this may be due to the small sample size in each group.The haplotype network maps constructed by each gene showed that there was a direct evolutionary relationship between the Binjiang Park population and the Wuhan population.This study preliminarily confirmed the results of epidemiological investigation that“the imported Oncomelania hupensis population of Binjiang Park,Nanchang City may be carried by the landscape reeds,which were transplanted from Huangpi district,Wuhan City”by using molecular population genetics method.Meanwhile,it is suggested that mitochondrial COI gene can provide abundant information to trace the origin of unknown population of Oncomelania hupensis.