Division of labour is a defining characteristic of the eusocial insect. In Mononorium pharaonis, the diploid individuals develop as reproductive gynes and workers who lose their reproductive opportunities for a lifetime. Remarkably, only the inseminated gyne assume the role of reproduction while the unmated individuals progressively transform into worker-like roles within the colony. Mating elicits notable physiological and behavioral change in females but our comprehension of the underlying genetic mechanisms remains constrained. Here, we analyzed the post-mating response in the reproductive tissues of M. paraonis. We showed that similar morphological status between young mated queens and virgins. To identify genetic factors responsible for the physiological and behavioural differences, we compared transcriptomic profiles of mated and unmated queens over two months of post-mating, focusing on the gene expression of the ovary and spermatheca. We found that the early distinction was initiated by the act of insemination, notably characterized by the activation of the innate immune system. The subsequent distinction diminished until 30-day after mating when more pronounced disparities appeared in the ovary. Apart from the time-dynamic gene regulatory network (GRN), the expression of a geneset remains consistently associated with the identity, indicating a robust amplification of the reproductive impact on the ovary. These results showed the temporal dynamics of the post-mating GRN, which serves to enhance our comprehensive understanding of the genetic mechanisms driving the divergent trajectories in mated and unmated females, and offer insights into its evolutionary significance in the broader context of reproductive adaptations.
Unraveling the dynamic post-mating gene regulatory network in the reproductive roles of Monomorium Pharaonis