Association between gut microbiota and diapause preparation in the cabbage beetle: a new perspective for studying insect diapause

Gut microbiota mediate the nutritional metabolism and play important roles in human obesity. Diapausing insects accumulate large fat reserves and develop obese phenotypes in order to survive unfavorable conditions. However, the possibility of an association between gut microbiota and insect diapause has not been investigated. We used the Illumina MiSeq platform to compare gut bacterial community composition in nondiapause- (i.e. reproductive) and diapause-destined female cabbage beetles, Colaphellus bowringi, a serious pest of vegetables in Asia. Based on variation in the V3-V4 hypervariable region of 16S ribosomal RNA gene, we identified 99 operational taxonomic units and 17 core microbiota at the genus level. The relative abundance of the bacterial community differed between reproductive and diapause-destined female adults. Gut microbiota associated with human obesity, including Bacteroidetes, Firmicutes, and Proteobacteria, showed a good correlation with diapause. This association between gut microbiota and diapause in the cabbage beetle may open a new avenue for studying insect diapause, as well as developing a natural insect obesity model with which to explore the mechanisms responsible for human obesity.