DOI: 10.5061/dryad.ncjsxkt8p
title: Data from: Mixed evidence for intralocus sexual conflict from male-limited selection in <em>Drosophila melanogaster</em>

description: Sexual conflict over shared traits – intralocus sexual conflict (IaSC) –
 may be common and consequential, but experimental tests of its relative
 magnitude are challenging and limited in number. We use a sex-limited
 selection experiment, designed to subject haplotypes of Drosophila
 melanogaster to selection for male fitness without opposing selection
 acting on female fitness. Importantly, we use three novel base populations
 to compare results with those from the LHM population, the sole population
 investigated using this technique. In contrast with previous studies, we
 find that the male fitness of haplotypes subject to male-limited selection
 (ML populations) is not consistently better than their matched (MC)
 controls when tested in the “wildtype” state. Males from ML lines did not
 outperform controls in competitive fitness assays, mate choice trials,
 fecundity induction, or sperm offense tests. As predicted, genetic
 variation for male fitness was reduced, with low fitness haplotypes
 apparently removed by selection, but this was only surveyed in one
 replicate population pair and included a potential artifact in the
 protocol. Female fitness was markedly reduced by carriage of ML
 haplotypes, as predicted by sexual antagonism. Hence, our results are only
 partially consistent with the IaSC hypothesis, raising questions about the
 relative contribution of sexual conflict to the standing genetic variation
 in these populations and the potential role of artifacts in the protocol
 that may have obscured our ability to detect IaSC.
description: Full methodological details are provided in the associated
 publication. Breeding designs used to produce animals from various
 treatments can be found in the online supplement. 
 <em>Competitive reproductive fitness</em> (CRF) was
 assayed for both males and females against competitive recessive (Cr)
 marker stocks in equal numbers. Test females were collected as virgins and
 test males at 10–11 days post-oviposition. On day 12, groups of 30 MC or
 ML flies were combined with 30 Cr of the same sex and 50 Cr of the
 opposite sex in ventilated “mini-cages” with yeast for 2 days. Six
 competition arenas (“contests”) were set up per population, and offspring
 proportions from six egg vials per arena were counted to estimate
 CRF. Fitness assays for <em>hemiclonal
 analysis</em> followed a similar design with reduced competition
 size to accommodate 76 lines. For males, 4 test flies were combined with 4
 Cr males and 6 Cr females. For females, 4 virgins were combined with 3 Cr
 males, and productivity (pupal count) was used as a proxy for fitness. Up
 to 5 contests were run per line, and complete hemiclonal data were
 obtained for 76 of 80 lines. <em>Male mating
 success</em>: Single test males were combined with a Cr male and a
 Cr virgin female. When one pair initiated copulation, the rival male was
 removed without disturbance, and the mating event was monitored until
 separation. Mating latency, mating duration, and the offspring produced
 (sex ratio, fecundity induction, and eye-color marker) were recorded to
 identify the successful sire. Fifty binary choice vials were set up per
 treatment within each replicate line. 
 <em>Sperm competition (P2)</em>: Groups of 12 virgin Cr
 females were combined with Cr males, and matings were closely observed.
 After mating, Cr males were removed. On day 13, 10 “target” males (MC or
 ML) were added to each vial for a second mating, observed for ~3 hours to
 prevent multiple matings. Ten females per vial were then isolated for 24
 hours to lay eggs. Offspring were scored by eye color to determine the
 proportion sired by the second male. Each treatment included 30 replicate
 vials.
description: # Data from: Mixed evidence for intralocus sexual conflict from
 male-limited selection in *Drosophila melanogaster* ## Title of Dataset
 Wild-type estimates of fitness, sperm comp, mate choice, and heritable
 variation for fitness under male-limited experimental evolution. ####
 Associated Publication * **Title:** Mixed evidence for intralocus sexual
 conflict from male-limited selection in Drosophila melanogaster *
 **Journal:** Journal of Heredity * **Authors:** * Harshavardhan
 Thyagarajan, * Imran Sayyed, * Mindy G. Baroody, * Joshua A. Kowal, * Troy
 Day, * Adam K. Chippindale #### Dataset Overview This dataset contains
 experimental data on fitness, mate choice and sperm competition
 measurements for male-limited and control selection populations; and
 fitness measurements for hemiclones expressed male and female backgrounds.
 The data pertains to experimentally evolved *Drosophila melanogaster*
 populations. The data are provided as CSV files. The six files correspond
 to different experimental assays: 1. `M_CRF_wt.cr.csv` — Male competitive
 reproductive fitness assay 2. `F_CRF_wt.cr.csv` — Female competitive
 reproductive fitness assay 3. `M_SC_wt.cr.csv` — Male sperm competition
 assay data 4. `M_MC_wt.cr.csv` — Male mating competition (mating latency
 and duration) 5. `M_HClines.csv` — Hemiclonal male competitive
 reproductive fitness assay 6. `F_HClines.csv` — Hemiclonal female
 fecundity assay Common variables: 1. Selection ML — Male limited MC —
 Matched control (matched by replicate number, for example ML1 and MC1) 2.
 Treatment — In experiments where the ML haplotypes were expressed in a
 variety of treatments, these are labelled as follows. If a treatment
 variable is not provided, it means that all the animals under selection
 "ML" were studied under conditions resembling MLSD. Where
 `Treatment` is provided, the variable `Selection` is normally excluded as
 `Treatment` covers this information. MLSD — ML, single dose of entire
 haplotype MLSDa — ML, single dose of autosomes MLDD — ML, double dose MC —
 MC (analogous to MLDD) 3. Replicate — This describes the replicate pairs
 of selected and control populations. It is necessary to clarify here the
 method of setting up replicates. Commonly, a single source population is
 used to derive n statistical replicate populations under selection /
 control conditions. Here rather, we use 3 long separated populations
 (themselves originally derived as statistical replicates over 20 years
 prior) to initiate each selection / control pair. 4. Contest — An
 identifier for a distinct chamber in which an assay was conducted. In
 fitness assays, in each contest, we had 30 target animals compete 30
 recessively marked competitors of the same sex for the maximum
 reproductive output, in the presence of 50 animals of the opposite sex.
 #### File Details 1\. **`M_CRF_wt.cr.csv`** * **Dimensions:** 851 rows × 7
 columns **2. `F_CRF_wt.cr.csv`** * **Dimensions:** 423 rows × 7 columns *
 **Columns:** (for both 1 & 2) * `Gen` — Generation number, categorical
 * `Treatment` — Described above, categorical * `Replicate` — Described
 above, categorical * `Contest` — Described above, categorical * `Vial` —
 Vial number, statistical replicate unit of competitive outcome from a
 single contest, categorical * `Red` — Number of red-eyed progeny, count *
 `Brown` — Number of brown-eyed progeny, count **3. `M_SC_wt.cr.csv`** *
 **Dimensions:** 619 rows × 6 columns * **Columns:** * `Treatment` —
 Described above, categorical * `Replicate` — Described above, categorical
 * `Bundle` — Analogous to contest - a bundle represents flies that were
 housed together during testing, categorical * `Vial` — Each vial
 represents data from a single female laying eggs. Nested within bundle as
 with vials within contest in CRF assays, categorical * `U` — Number of
 mutant (recessively marked) offspring, count * `WT` — Number of wild-type
 progeny, count **4. `M_MC_wt.cr.csv`** * **Dimensions:** 273 rows × 14
 columns * **NAs:** NA here refers to cells where the data is not
 available. * **Columns:** * `Selection` — Described above, categorical *
 `Replicate` — Described above, categorical * `Vial.ID` — Identifier of
 independent contest between animals in this experiment, not nested here,
 categorical * `Obs.start.time` — Observed start time of assay, hh:mm *
 `Mating.start.time` — Time when mating began, hh:mm * `Mating.end.time` —
 Time when mating ended, hh:mm * `Mated.male` — Identity of mating male (wt
 - aka target / bw - recessive competitor), categorical * `Males` — Number
 of males present in vial, count * `Females` — Number of females present in
 vial, count * `Obs.start.time.Corr` — Converted observation start time
 (minutes since ref), numeric * `Mating.start.time.Corr` — Converted mating
 start time, numeric * `Mating.end.time.Corr` — Converted mating end time,
 numeric * `Latency` — Time from observation to mating start, minutes *
 `Duration` — Duration of mating, minutes **5. `M_HClines.csv`** *
 **Dimensions:** 367 rows × 5 columns * **Columns:** * `Selection` —
 Described above, categorical * `Line` — Hemiclone line number, categorical
 * `Vial` — Vial number - analogous to contest here (no nesting within
 another variable), categorical * `Red.offspring` — Number of red-eyed
 progeny, count * `Peach.offspring` — Number of brown-eyed progeny, count
 **6. `F_HClines.csv`** * **Dimensions:** 367 rows × 5 columns *
 **Columns:** * `Selection` — Described above, categorical * `Line` —
 Hemiclone line number, categorical * `Vial` — Vial number - analogous to
 contest here (no nesting within another variable), categorical *
 `Pupal.count` — Number of offspring of target females, counted at the
 pupal stage, count * `Dams.Count` — Number of females that were introduced
 into egg-laying vials (typically designed to be 4, but sometimes fewer),
 count **License** This dataset is released under the **CC0 1.0 Universal**
 license in accordance with Dryad’s policies. **Citation** Thyagarajan, H.
 et al. (2025). *Dataset: Mixed evidence for intralocus sexual conflict
 from male-limited selection in Drosophila melanogaster*. Dryad Digital
 Repository. DOI: 10.5061/dryad.ncjsxkt8p