Microbial community reshuffling during diapause in a scyphozoan jellyfish

Diapause is an adaptive strategy that enables organisms to survive in harsh environments. Mounting evidence suggests that microbial associations play key roles in the homeostasis of metaorganisms. However, the vital role of microbes in host diapause remains unclear. Jellyfish, a basal metazoan, may provide an opportunity to explore the fundamental microbial associations in diapause. This study aimed to explore the taxonomic and functional profiles of associated microbiota in diapause (podocyst reproduction) of scyphozoan jellyfish Aurelia coerulea using 16S rRNA gene sequencing. The results revealed the microbial community composition in the diapausing podocysts induced by food deficiency was significantly distinct from that in the budding reproduction with sufficient food. The microbial diversity was significantly higher in the diapausing podocysts of A. coerulea compared to other stages. In the podocysts of highly diverse microbes, bacteria predicted to be involved in chitin biosynthesis, DNA repair, oxidative stress resistance, energy metabolism, and pathogen defense showed significant abundance, may assist jellyfish in forming a podocyst shell, maintaining basic energy supply, and resisting potential damage during diapause. These findings highlight the essential role of microbial communities during jellyfish diapause and provide new insights into ancestor mechanisms of host-microbe interactions during animal diapause.