Wolbachia诱导胞质不亲和(cytoplasmic incompatibility,CI)是对寄主的生殖调控中最常见的一种方式,在不同种群中CI表达的差异较大。以二斑叶螨Tetranychus urticae辽宁兴城(LN)和江苏徐州(JS)两个地理种群为实验材料,经筛选获得100%感染Wolbachia和不感染Wolbachia的品系,通过杂交实验和实时定量PCR的方法研究寄主遗传背景、雄螨日龄、温度以及雄螨体内Wolbachia菌量等因子对我国二斑叶螨体内Wolbachia诱导CI能力的影响。结果表明:1,3,5和7日龄的雄螨诱导的CI的强度没有差异,表明雄螨日龄对我国二斑叶螨体内Wolbachia诱导CI的能力没有影响。二斑叶螨分别放在20℃的低温、25℃的适温和30℃的高温条件下饲养时,Wolbachia诱导CI的能力也没有任何变化,表明温度对我国二斑叶螨体内Wolbachia诱导CI的能力也没有影响。江苏徐州种群所感染Wolbachia菌量显著高于辽宁兴城种群,并且这两个种群感染Wolbachia菌量都随着雄螨日龄的增大而显著增加,表明Wolbachia菌量对我国二斑叶螨体内Wolbachia诱导CI的能力没有影响;江苏徐州种群内Wolbachia不能诱导CI可能是Wolbachia株系与寄主的遗传背景共同作用的结果。研究结果为进一步了解Wolbachia的生殖调控机理提供了重要依据。
The cytoplasmic incompatibility(CI) is the most common effect of Wolbachia on the reproduction of its arthropod hosts,and the expression of CI differs greatly among different populations.Using the Jiangsu(JS) and Liaoning(LN) populations of the two-spotted spider mite,Tetranychus urticae Koch(Acari:Tetranychidae),as experimental materials,100% infected and uninfected Wolbachia lines were obtained by screening.The present study tried to evaluate some factors influencing the expression of CI in the spider mite by crossing experiment and Real-time quantitative PCR.These factors include age of host,temperature,host genes and Wolbachia density.The 1,3,5,7-day-old virgin males were used to investigate the influence of host age on Wolbachia-induced CI.The results showed no effect of age on CI,suggesting that host age does not reduce the sperm modification induced by Wolbachia.The effect of temperatures(20℃,25℃ and 30℃) on the CI induced by Wolbachia was also checked.Neither high nor low temperatures influenced the expression of CI.Wolbachia density in males of the JS population,as measured by quantitative PCR using the wsp(surface protein of Wolbachia) gene,was significantly higher than that in the LN population.In addition,in both the JS and LN populations,Wolbachia density increased with the age of male hosts.Wolbachia density also showed no effect on CI.We estimated the variability of CI expression between the JS and LN population of T.urticae was due to the interaction between Wolbachia and host genotypes.The results might provide foundation for understanding the mechanisms of reproductive manipulation induced by Wolbachia.