DOI: 10.5061/dryad.03768
title: Data from: Developmental environment mediates male seminal protein investment in Drosophila melanogaster

description: Males of many species fine-tune their ejaculates in response to sperm
 competition risk. Resource availability and the number of competitors
 during development can also strongly influence sperm production. However,
 despite the key role of seminal proteins in mediating reproductive
 processes, it is unclear whether seminal protein investment is dependent
 on the developmental environment. We manipulated the developmental
 environment of Drosophila melanogaster by rearing flies at low and high
 density. As expected, this resulted in large and small (i.e. high and low
 condition) adult phenotypes, respectively. As predicted, large males
 produced more of two key seminal proteins, sex peptide (SP) and ovulin,
 and were more successful at obtaining matings with both virgin and
 previously mated females. However, there was only a weak and
 non-significant trend for large males to transfer more absolute quantities
 of SP at mating, and thus, small males ejaculated proportionally more of
 their stored accessory gland SP resources. Males transferred more
 receptivity-inhibiting SP to large females. Despite this, large females
 remated more quickly than small females and thus responded to their
 developmental environment over and above the quantity of SP they received.
 The results are consistent with two non-mutually exclusive hypotheses.
 First, flies might respond to condition-dependent reproductive
 opportunities, with (i) small males investing heavily in ejaculates when
 mating opportunities arise and large males strategically partitioning SP
 resources and (ii) small females remating at reduced rates because they
 have higher mating costs or need to replenish sperm less often. Second,
 flies may be primed by their larval environment to deal with similar adult
 population densities, with (i) males perceiving high density as signalling
 increased competition, leading small males to invest proportionally more
 SP resources at mating and (ii) females perceiving high density as
 signalling abundant potential mates, leading to a higher sexual
 receptivity threshold. Thus, by influencing the mating frequencies of both
 sexes, as well as the quantity of seminal proteins produced by males and
 received by females, the developmental environment is likely to have
 far-reaching and sex-specific consequences for sexual selection and sexual
 conflict.
description: Female tissue Sfp
 detectionValues from ELISAs of
 Large or Small female reproductive tracts spiked with a consistent amount
 of SP or OV, to test for interference of female tissue on Sfp detection.
 See methods: "Test of interference of female tissue with detection of
 Sfps in ELISAs".Experiment 1 fly
 weightsMass of flies from
 Experiment 1Experiment 4 fly
 weightsMass of flies from in
 Experiment 4Experiment_2_rival_male_sizeExperiment 2: Effects of rival male size on SP production and transfer. Data on latency to mating; mating duration; male SP; female SP; proportion SP transferred.Experiment_1_male_SP and OV productionExperiment 1: SP and OV produced by males in their accessory glands.Experiment_1_male_SP and OV.xlsxExperiment 1_Sfp allocation to femalesExperiment 1: Small and Large males and females. Mating latency and duration; absolute quantity of Sfps transferred to females during mating.Experiments 3 and 4Experiments 3 and 4: Latency to mating, mating duration and remating data.Experiment 4_Courtship and RejectionExperiment 4: Courtship and Rejection data