Ovary-specific transcriptomes analysis revealed Wolbachia-induced reproductive incompatibility in Laodelphax striatellus

Wolbachia are intracellular bacteria that infect a wide range of invertebrate, and which influence the egg production and reproductive incompatibility of hosts. Wolbachia-induced cytoplasmic incompatibility (CI) is strong and almost complete in the planthopper Laodelphax striatellus, involving embryonic lethality in the crosses between Wolbachia-uninfected females and infected males. The ovary of L. striatellus plays an important role in CI process. However, very little is known about the underlying molecular functions of ovary in the interaction between Wolbachia and L. striatellus. Here we isolated ovaries from 3-day-old females and compared transcriptomes of Wolbachia-uninfected or infected females in four crosses (Wolbachia-infected female and Wolbachia-infected male (I*I), Wolbachia-infected female and Wolbachia-free (I*F), Wolbachia-free and Wolbachia-infected male (F*I), Wolbachia-free female and Wolbachia-free male (F*F)). The differentially expressed unigenes between the ovaries of four crosses were different, and only 11 unigenes were co-regulated of oocyte meiosis in the four crosses. Oocyte meiosis gene related to troponin was activated upon in the CI cross (F*I), whereas the genes involved in mitotic, cyclin and protein kinase were suppressed. An expression profile of host oocyte meiosis genes in L. striatellus ovaries revealed maternal-effect embryonic lethality induction. These findings provide clues on the roles of the ovary in Wolbachia-induced cytoplasmic incompatibility and aid in the understanding of the interaction between Wolbachia and L. striatellus.