Post-mating change in excretion by mated Drosophila melanogaster females is a long-term response that depends on sex peptide and sperm

Abstract

Drosophila seminal fluid proteins elicit physiological and behavioral changes in the female after mating. For example, the seminal protein sex peptide (SP) causes females to lay more eggs, reduce receptivity to re-mating, consume more food and produce more concentrated excreta upon mating. It has been reported that SP indirectly increases food consumption as a result of its stimulation of egg production, but its role in producing more concentrated excreta in the mated female was reported to be independent of egg production. Additionally, it has been shown that SP's effect on food consumption persists for several days after mating, while it is unknown whether this is true for its effect on excretion. SP can have both transient and long-term effects on mated females; the latter occur because of the peptide's binding to, and slow release from, sperm in the female. Here we used timed measures of excretion by female flies that had mated to males mutant in SP or in its regulators, to test the duration of SP's effect on excretion. We found that SP's effect on excretion persists for at least ~1 week after mating, and that this persistence requires that SP bind to and be released from sperm. Although these binding/release requirements of SP are similar to those for increased egg production (and consequent increased food intake) following mating, we find that the long-term change in excretion phenotype is only partially dependent on the presence of eggs in the female. Our data indicate that a change in intestinal transit is part of the long-term post-mating response elicited by the gradual release of sperm-bound SP in the female after mating, even though it is not fully dependent of other long-term responses elicited by SP.

Integrated 3D view of postmating responses by the Drosophila melanogaster female reproductive tract, obtained by micro-computed tomography scanning

“…Within the female RT, SFPs induce a series of conformational changes of the uterus (16,22). Specific SFPs increase ovulation and oviposition rates (12,13,23), promote sperm storage (16,24,25), increase feeding (26), decrease intestinal transit rates (27,28), and increase synaptic development at female RT neuromuscular junctions (10). Although much is known about the molecules and interactions that mediate these female postmating responses, next to nothing is known about the physical mechanics of the postmating changes and their response to male and female molecules.…”

Sexual Conflict and Seminal Fluid Proteins: A Dynamic Landscape of Sexual Interactions

“…For example, receipt of SP increases the amount of food consumed by D. melanogaster females (Ribeiro and Dickson 2010) and changes the female’s food preferences. SP also affects the rate of intestinal transit, with mated D. melanogaster females having slower intestinal transit than virgins, producing more concentrated excreta, presumably because they have absorbed more water (and nutrients) from their food (Cognigni et al 2011; Apger-McGlaughon and Wolfner 2013). In contrast, mated female Ae.…”

Neprilysins: An Evolutionarily Conserved Family of Metalloproteases That Play Important Roles in Reproduction in Drosophila

“…NPF has also been implicated in regulating feeding behavior in Drosophila (Lee et al 2004), where increases in food intake are correlated with but not completely dependent on post-mating increases in female egg laying (Carvalho et al 2006;Apger-Mcglaughon and Wolfner 2013). Another candidate, allatostatin A (AstA), has been implicated in regulating oviduct muscle contraction in other arthropods (Donini and Lange 2002;Garside et al 2002;Woodhead et al 2003).…”