The role of fruitless P3 and P4 transcripts in Drosophila melanogaster
Abstract
The fruitless gene is highly conserved across many insect species, and its role in sex determination and sexual behaviour in Drosophila melanogaster males has been well characterized. The fruitless gene is alternatively spliced to produce at least 15 transcripts, but little is known about the alternative transcripts not involved in sexual traits. Transcripts beginning with the P3 and P4 first exons have previously been shown to be more heavily expressed during developmental stages of the D. melanogaster life cycle and have been implicated in developmental and fitness traits. Yet, these transcripts have never been assessed for their involvement in developmental traits. To study the role of these transcripts individually, the expression of fruitless P3 and P4 transcripts were reduced through RNA interference (RNAi) in combination with the Gal4/UAS binary system. Subsequent verification through quantitative PCR (qPCR) found that P3 transcript was successfully knocked down but P4 transcript was not. Assays scoring the influence of fruitless P3 on development found that knockdown of P3 transcript expression causes lethality at the pupal stage of development, where larvae form pupae but do not progress past this stage of development to form adult flies. This demonstrates that fruitless P3 plays a critical role in development, and that knockdown of P3 alone is sufficient to induce lethality.