Parasitization of Glover by Gahan Causes Shifts in the Ovarian Bacterial Microbiota.

BACKGROUND

Glover is an important agricultural pest distributed worldwide. Gahan is the main parasitoid wasp of . Previous studies have shown that parasitization causes reduced egg production in , but the effects of parasitism on the symbiotic bacteria in the host ovaries are unknown.

RESULTS

In this study, we analyzed the microbial communities in the ovaries of without and after parasitization. Whether parasitized or not, was the dominant genus of symbiotic bacteria in the ovaries, followed by facultative symbionts including , , and . The relative abundance of in the aphid ovary increased after parasitization for 1 d in both third-instar nymph and adult stages, but decreased after parasitization for 3 d. The shifts in the relative abundance of in both stages were the same as those observed for In addition, the relative abundance of remarkably decreased after parasitization for 1 d and increased after parasitization for 3 d. A functional predictive analysis of the control and parasitized ovary microbiomes revealed that pathways primarily enriched in parasitization were "amino acid transport and metabolism" and "energy production and conversion." Finally, RT-qPCR analysis was performed on , , and . The results of RT-qPCR were the same as the results of 16S rDNA sequencing.

CONCLUSIONS

These results provide a framework for investigating shifts in the microbial communities in host ovaries, which may be responsible for reduced egg production in aphids. These findings also broaden our understanding of the interactions among aphids, parasitoid wasps, and endosymbionts.