烟粉虱MEAM 1隐种主要内共生菌的定位和分布

烟粉虱MEAM 1隐种是一种重要的世界性入侵害虫,共生菌在其种群入侵和扩张中起着不可忽视的作用。本研究采用荧光原位杂交技术(FISH),明确其携带的初生共生菌(Candidatus Portiera aleyrodidarum)和次生共生菌(Candidatus Hamiltonella defensa和Rickettsia sp.)在不同发育阶段虫体中的定位和分布。结果显示,烟粉虱MEAM 1隐种卵、若虫和成虫3个阶段均携带3种共生菌,Portiera和Hamiltonella菌集中分布于含菌细胞中,其中Hamiltonella呈环形包裹于含菌细胞周边;Rickettsia既在菌胞中呈“集中”分布,也“随机”分布于虫体其他部位或器官。上述结果明确了这3种共生菌在MEAM 1烟粉虱各个发育阶段的分布特征,同时证明3种共生菌均能通过烟粉虱雌虫垂直传播,为进一步揭示内共生菌在烟粉虱入侵过程中的作用打下基础。

Localization and distribution of the main endosymbionts in Bemisia tabaci MEAM 1

Bemisia tabaci (Gennadius) MEAM 1 is one of the most devastating invasive pests worldwide and its endosymbionts play an important role in the invasion and expansion of this pest insect. In this study, the fluorescence in situ hybridization (FISH) was used to identify the localization and distribution of the primary endosymbiont (Candidatus Portiera aleyrodidarum) and the secondary endosymbionts (Candidatus Hamiltonella defensa and Rickettsia sp.) in different developmental stages of B.tabaci MEAM 1. Three symbiotic bacteria were found in the eggs,nymphs,and adults of B.tabaci MEAM 1. Among them, Portiera and Hamiltonella were located inside the bacteriocytes and Hamiltonella around the bacteriocyte. Rickettsia was located both inside the bacteriocyte and randomly distributed in other parts or organs. These results revealed the distribution characteristics of the three endosymbionts in different developmental stages of B.tabaci MEAM 1, and provided evidence that all the three endosymbionts are vertically transmitted through the female of B.tabaci, and thus lay a foundation for further understanding the roles of endosymbionts in the invasion of B.tabaci.