Differential gene expression underpinning production of distinct sperm morphs in the moth Galleria mellonella.

The wax moth Galleria mellonella produce two sperm types: fertile (eupyrene) sperm and infertile (apyrene) sperm, in a phenomenon termed sperm heteromorphism. Previous research in other Lepidopteran species has revealed unique proteomes in the mature eupyrene and apyrene sperm. However, a systematic transcriptomic analysis of earlier, highly transcriptomically active stages in eupyrene vs apyrene sperm development has not been completed. Therefore, this study conducted RNA-seq on 10 primary spermatocyte cysts from 5 larval testes committed to the eupyrene developmental pathway, and 10 cysts from 5 pupal testes committed to the apyrene pathway. Differential gene analysis was then conducted, and revealed many DEGs between the larval and pupal cysts. These transcriptomic differences early on in eupyrene vs apyrene sperm development explain the subsequent unique proteomes of the mature sperm, and their unique morphology and function. Our RNA-seq dataset also provides genes of interest for future investigation, with potential applications in targeting sperm heteromorphism as a pest control strategy of Lepidopteran pests.