Wolbachia和Cardinium对皮氏叶螨生殖的影响及在寄主体内的定位

Wolbachia和Cardinium均为母系遗传的胞内共生菌， 它们能够通过诱导胞质不亲和（cytoplasmic incompatibility, CI）以调控寄主的生殖。目前， 关于Wolbachia和Cardinium共同对同一寄主进行生殖操控的机制还不清楚。本研究以皮氏叶螨Tetranychus piercei McGregor广州种群为实验材料， 通过杂交实验和荧光原位杂交的方法， 研究Wolbachia和Cardinium单感染和双感染对寄主生殖的影响。结果表明： 单感染Wolbachia诱导较弱的CI， 不亲和组合的未孵化率为17.8%±1.6%。单感染Cardinium及双感染Wolbachia和Cardinium能诱导高强度的CI, 不亲和组合的未孵化率分别为70.3%±1.3%和72.9%±1.2%。同时双感染Wolbachia和Cardinium雌螨的平均产卵量为35.2±1.2， 显著高于单感染和不感染的雌螨的产卵量。Wolbachia 和Cardinium分别诱导以及共同诱导CI的水平与精子形成过程中的感染情况有关。Wolbachia和Cardinium的垂直传播模式结果显示， 在卵的不同发育阶段， Wolbachia和Cardinium主要伴随着营养物质从滋养细胞、 中肠、 输卵管进入发育中的卵。研究结果为进一步了解 Wolbachia和Cardinium的母系遗传机制提供了重要依据。

Reproductive effects and localization of Wolbachia and Cardinium in the spider mite Tetranychus piercei ( Acari: Tetranychidae)

Wolbachia and Cardinium,with the ability to induce cytoplasmic incompatibility(CI),are maternally inherited intracellular bacteria known to manipulate the reproduction of their hosts.The exact mechanisms of CI which is induced by these two endosymbionts in the same host are unknown.This study tried to investigate the reproductive manipulation of Wolbachia or/and Cardinium infected spider mite Tetranychus piercei McGregor by crossing experiment and fluorescence in situ hybridization(FISH).The results indicated that Wolbachia-infected males induced weak CI.In Guangzhou population of the spider mite,approximate 17.8%±1.6% of all eggs did not hatch in the incompatible cross U/Iw.Cardinium-infected and Wolbachia and Cardinium doubly infected males caused severe CI.The unhatched eggs in the incompatible cross U/Ic and U/Iwc accounted for 70.3%±1.3% and 72.9%±1.2%,respectively,the number of eggs laid per doubly infected female was 35.2±1.2,significantly higher than that of singly(Wolbachia or Cardinium) infected female.There is a positive correlation between CI levels and infection status of the developing sperm.Wolbachia and Cardinium mainly enter the oocytes with trophic flow from nurse cells,midgut and oviduct.The results might provide foundation for understanding the maternally inherited mechanisms of Wolbachia and Cardinium.