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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%(765/1206)和36.57%(441/1206),嗜牛血组牛饵帐和人饵帐的重捕比例分别为68.22%(1039/1523)和31.78%(484/1523),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rDNAITS2基因碱基序列无差异,均为469 bp。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。
Objective To investigate whether there is genetic differentiation based on rDNA-ITS2 sequence among populations of Anopheles sinensis different in homosexuality and haemophilic habits. Methods A large number of wild Anopheles mosquitoes were trapped in the villages of Anopheles sinensis with high density and Anopheles mosquito breeding habitat at the same time. Anopheles sinensis was separated and identified by morphological identification and returned to laboratory for routine feeding. A large enclosed greenhouse with suitable temperature and humidity was selected as the place of marker-release-recapture technology for female mosquitoes. The above-mentioned artificial bait group and the Chinese bait group were respectively labeled with red and yellow phosphors and released in the middle of the greenhouse at the same time At both ends of the greenhouse were set bait and bait bait trapped (reoccupy) Anopheles sinensis. The Anopheles sinensis female mosquitoes, trapped twice by human bait and bait account, were divided into the blood-dripping group and the blood-addicted group, and were brought back to the laboratory for passage. The mosquitoes were respectively fed human blood and bovine blood. Two groups of female mosquitoes of the 1st generation of Anopheles mosquitoes once again using the above-mentioned marker-release-recapture technology, screening anthropophagus and blood of the Anopheles sinensis strains; and the two strains of Anopheles sinensis rDNA-ITS2 gene PCR amplification sequencing comparison. Results The percentage of re-entrapment of Anopheles sinensis bait and cattle bait in the wild-type parental anthropogenic group was 54.07% (339/627) and 45.93% (288/627), respectively The rates of recapture were 58.01% (409/705) and 41.99% (296/705), respectively. The parents of the two groups tended to choose the original blood-sucking host (χ2 = 19.42, P <0.01). In the first generation of anthropophagus blood group, the recoveries of Anopheles sinensis bait and cattle bait accounted for 63.43% (765/1206) and 36.57% (441/1206), respectively The recapture rates were 68.22% (1039/1523) and 31.78% (484/1523) respectively. There was a more significant preference for the blood-sucking habits of mosquitoes in both groups (χ2 = 271.69, P <0.01) Genetic differentiation phenomenon. However, the results of PCR amplification and sequencing showed that there was no difference in the base sequence of rDNAITS2 gene between the two strains of mosquitoes, both of which were 469 bp. Conclusion No genetic differentiation based on rDNA-ITS2 sequence occurred in the Anopheles sinensis syndroms with different haematological habits.