伪威氏按蚊mtDNA-Cytb基因群体遗传学研究

目的探讨不同地理区域伪威氏按蚊的群体遗传结构与差异,发现伪威氏按蚊的群体遗传与进化规律。方法对云南、西藏和缅甸伪威氏按蚊,采用mtDNA-Cytb基因进行群体遗传分析;测序结果以Chromas（Version 2.13）进行核对,序列比对采用ClustalX进行,MEGA软件包统计序列特征,运用ARLEQUIN（Version 3.0）统计和计算各群体的基因序列碱基分化参数;群体遗传结构由ARLEQUIN的AMOVA模块计算群体间的分化参数Fst（F-statistics）、基因流水平Nm（Nm=1-Fst/4Fst）等指标;TCS 1.21计算群体中的单倍型并构建单倍型间的家系网络图;MEGA软件构建单倍型之间的系统聚类树。结果伪威氏按蚊mtDNA-Cytb基因均各扩增出单一清晰的目的条带;mtDNA-Cytb基因分子标志的TCS单倍型家系网络图显示高水平平行演化;单倍型NJ聚类未显示出聚类关系与地理距离之间的相关性;AMOVA分析发现群体内差异远远大于群体间差异,伪威氏按蚊不同群体2分子标志的Fst和Nm值分别为0.01696,4.168。结论 mtDNA-Cytb基因可以作为研究按蚊群体遗传结构的理想分子标志;伪威氏按蚊群体间交流频繁,目前尚未发生群体分化。

Population genetics of mtDNA-Cytb gene from Anopheles Pseudowillmori

To study the hereditary constitution and difference of An.pseudowillmori,and to understand its regular pattern of heredity and evolution,they were collected from Yunnan Province,Xizang Autonomous Region and Myanmar.Molecular markers of mtDNA-Cytb were used for the population genetic analysis.Gene sequence were compared and reconfirmed by Chromas（Version 2.13）and Clustal X,and the MEGA 3.1 was applied to analyze the sequence signature and construct the clustering tree.TCS 1.21 was adopted to calculate the gene haplotype and construct the family constellation network map.AMOVA was performed by Arlequin software for the parameter of Fst and Nm.A single and clear expected fragment of mtDNA-Cytb gene were amplified.Family constellation network map showed the high level homoplasy.NJ clustering with haplotype found no correlation between geography distance and clustering.AMOVA analysis showed variances among population were larger than that between populations.Fst and Nm of the two molecular markers among different population were 0.01696 and 4.168.The mtDNA-Cytb was optional molecular markers for study of the population genetics.Gene communication was frequently and no obvious variance was found between different geography areas of An.pseudowillmori.