Mating and blood-feeding induce transcriptome changes in the female sperm storage organs of the yellow fever mosquito Aedes aegypti

Aedes aegypti mosquitoes are the primary vectors of numerous viruses that impact human health. As manipulation of reproduction has been proposed to suppress mosquito populations, elucidation of biological processes that enable males and females to successfully reproduce is necessary. One essential process is female sperm storage in specialized structures called spermathecae. Aedes aegypti females typically mate once, requiring them to maintain sperm viably to fertilize eggs they lay over their lifetime. Although male seminal fluid proteins have been identified that are necessary for proper sperm storage, few female proteins that participate in this important process have been identified. Spermathecal gene products are required for sperm storage and sperm viability in Drosophila, and a spermathecal-derived heme peroxidase is required for the long-term fertility of Anopheles gambiae. Products of the Ae. aegypti spermathecae, and their response to mating, are largely unknown. Further, although female blood-feeding is essential for anautogenous mosquito reproduction, the transcriptional response to blood-ingestion remains undefined in any reproductive tissue. We conducted an RNAseq analysis of spermathecae from virgin, mated only, and mated and blood-fed females at 6, 24, and 72 h post-mating. We identified significant differentially expressed genes in each group at each timepoint and show that a blood-meal following mating induces a greater transcriptional response in the spermathecae than mating alone. This study provides the first view of elicited mRNA changes in the spermathecae by a blood-meal in mated females.