Sex‐peptide activates juvenile hormone biosynthesis in the Drosophila melanogaster corpus allatum

Abstract

Mating elicits two well-defined reactions in sexually matured females of many insects: reduction of receptivity and increased oviposition. These post-mating responses have been shown to be induced by factors synthesized in the reproductive tract of the adult male and transferred in the seminal fluid to the female during copulation. One of these factors, named sex-peptide (SP), has been identified in Drosophila melanogaster. Using an in vitro radiochemical assay, we show that synthetic sex-peptide considerably activates juvenile hormone III-bisepoxide (JHB3) synthesis in corpus allatum (CA) excised from Days 3 and 4 post-eclosion virgin females. Base levels are significantly lower at emergence (Day 0) than on subsequent days, and only weak stimulation is obtained on Day 1, while none is obtained on Day 2, where maximal basal synthesis occurs. The CA of mated females cannot be stimulated further for at least 7 days, but regain responsiveness by Day 10 after mating. Synthesis of JHB3 stimulated by SP in vitro persists for at least 4 h after removal of the peptide. Development of responsiveness of the CA to SP in vitro is compared with development of the post-mating reactions of sex-peptide injected virgin females. Our results suggest that the CA is a direct target for SP in vivo and that sexual maturity is established separately for the two post-mating reactions.

Protein content and pattern during mucus gland maturation and its ecdysteroid control in honey bee drones

“…Some of the proteins, including the 36 amino acid-residue sex peptide of Drosophila melanogaster (Chen et al, 1988;Schmidt et al, 1993), are transported across the vaginal membrane (Lung and Wolfner, 1999) and reach their target sites via hemolymph transport. The Drosophila sex peptide targets the female's neuroendocrine axis, stimulating juvenile hormone biosynthesis by the corpus allatum (Moshitzky et al, 1996;Fan et al, 1999), which then controls the oogenic cycle in the ovaries (Soller et al, 1997). Sex peptide binding sites detected in the mushroom bodies appear to be the anatomical correlates for the postcopulatory behavioral 258 N.A.…”

Comparative structural modeling and inference of conserved protein classes in Drosophila seminal fluid

“…Intriguingly, two predicted Acp serpins, CG8137 and Acp76A, contain predicted hydrophobic pockets similar to PCIs. Given the importance of the hydrophobic hormone juvenile hormone in Drosophila reproduction (56) and Acp response (57), perhaps these Acps are involved in its binding or transport (or of another hydrophobic molecule).…”

The cost of reproduction: the devil in the details

“…It is cleaved from sperm [49], enters the female circulatory system and strongly stimulates egg production in addition to suppressing female remating. It also stimulates the biosynthesis of JH [50] which is thought to be the basis for increased vitellogenesis (yolk deposition) and elevated egg production after mating. The effect of the sex peptide on females is complex partially because it appears to involve modulation of a global endocrine regulator (JH) that is associated with a range of physiological effects, including altered immune function and metabolism.…”