Abstract: Objective Objective To investigate the existence of genetic divergence of sympatric populations of Anopheles sinensis of different feeding preferences based on the rDNA?ITS2 sequence differences. Methods Methods A large number of wild anopheles popu? lations were trapped all night by man?baited net and calf?baited net that had been set up between high?density natural villages of An. sinensis populations and vector?breeding sites，from which two groups of An. sinensis were separated by morphological iden? tification and brought back to the lab for conventional breeding. A large closed greenhouse which temperature and humidity was appropriate was selected as research settings of mark? release? recapture methods by female mosquitoes，in the center of which above An. sinensis populations baited by man and calf and respectively correspondingly marked by red and yellow phosphors were released in together，in each side of which An. sinensis were recaptured simultaneously by man?baited net and calf?baited net. An. sinensis populations trapped by man twice were brought back to the lab and bred with man?blood，correspondingly ones trapped by calf with calf ?blood. Man?preferring and calf ?preferring strains were screened respectively from An. sinensis which had been baited by man and calf by the mark? release? recapture methods after parent and F1 mosquitoes，and sequencing and aligning of both rDNA?ITS2 were conducted via PCR amplification. Results Results The recapture ratios of wild parental mosquitoes An. sinensis of man?preferring group by man?baited net and calf?baited net were 54.07%（339/627）and 45.93%（288/627）re? spectively，and ones of calf?preferring group by man?baited net and calf?baited net were 58.01%（409/705）and 41.99%（296/705）respectively. Two groups of parental mosquitoes trended towards selecting the original blood hosts in host?seeking prefer? ence（χ2 =19.42， P < 0.01） . The recapture ratios of F1 mosquitoes An. sinensis of man?preferring group by man?baited net and calf?baited net were 63.43%（765/1 206）and 36.57%（441/1 206），and ones of calf?preferring group by man?baited net and calf ?baited net were 68.22%（1 039/1 523）and 31.78%（484/1 523） . Two groups of F1 mosquitoes had more significant characteris? tics of selecting the original blood hosts in host?seeking preference（χ2 =271.69，P < 0.01）and showed the genetic differentia? tion phenomenon，but the results of sequencing and aligning of the rDNA?ITS2 via PCR amplification showed no difference in base sequence between the two strains and both were 469 bp. Conclusions Conclusions The genetic divergence based on the rDNA?ITS2 se? quence does not happen in An. sinensis sympatric populations of different feeding preferences.

Key words: Anopheles sinensis； Host?feeding preference； rDNA?ITS2；Genetic divergence； Mark?release?recapture method

摘要： 目的 目的 探讨同域分布而嗜血习性不同的中华按蚊种群是否存在基于rDNA?ITS2序列差异的遗传分化。方法 方法 在中华按蚊密度高的自然村和按蚊孳生地之间， 同时设人饵和牛饵帐通宵诱捕大量野外按蚊种群； 经过形态鉴定分离两 组中华按蚊， 并带回实验室常规饲养。选择一温湿度适宜的大型封闭温室作为雌蚊标记?释放?重捕技术的场所， 将以上 人饵组和牛饵组中华按蚊分别经红色和黄色荧光粉标记后在温室的中间一起释放， 同时在温室两端分别设人饵帐和牛 饵帐再次诱捕 （重捕） 中华按蚊。将两次均被人饵帐和牛饵帐诱捕的中华按蚊雌蚊分成嗜人血组和嗜牛血组， 带回实验 室饲养传代， 并分别饲以其蚊虫人血和牛血。两组中华按蚊的子1代雌蚊再次使用上述标记?释放?重捕技术， 筛选嗜人 血和嗜牛血的中华按蚊品系； 并对该两品系的中华按蚊rDNA?ITS2基因进行PCR扩增测序比对。结果 结果 野外亲代嗜人 血组中华按蚊人饵帐和牛饵帐的重诱捕比例分别为54.07% （339/627） 和45.93% （288/627）， 嗜牛血组牛饵帐和人饵帐的 重捕比例分别为58.01% （409/705） 和41.99% （296/705）， 两组亲代嗜血习性均趋向选择原吸血宿主 （χ2 =19.42， P < 0.01）。子1代嗜人血组中华按蚊人饵帐和牛饵帐的重捕比例分别为63.43% （765/1 206） 和36.57% （441/1 206）， 嗜牛血组 牛饵帐和人饵帐的重捕比例分别为68.22% （1 039/1 523） 和31.78% （484/1 523）， 两组蚊虫群体嗜血习性有更显著的选择 原吸血宿主的特性 （χ2 =271.69， P < 0.01）， 表现出遗传分化现象。但PCR扩增测序比对结果显示， 两品系蚊虫的rDNA? ITS2基因碱基序列无差异， 均为469 bp。结论 结论 嗜血习性不同的中华按蚊同域种群未发生基于rDNA?ITS2序列的遗传 分化。

关键词: 中华按蚊； 嗜血习性； rDNA?ITS2； 遗传分化； 标记?释放?重捕法