DOI: 10.5061/dryad.f6mb0
title: Data from: Is multifactorial sex determination in the house fly, Musca domestica (L.), stable over time?

description: Sex determination pathways evolve rapidly, usually because of turnover of
 master regulatory genes at the top of the developmental pathway. Polygenic
 sex determination is expected to be a transient state between ancestral
 and derived conditions. However, polygenic sex determination has been
 observed in numerous animal species, including the house fly, Musca
 domestica. House fly males carry a male-determining factor (M) that can be
 located on any chromosome, and an individual male may have multiple M
 factors. Females lack M and/or have a dominant allele of the Md-tra
 gene(Md-traD) that acts as a female-determining locus even in the presence
 of multiple copies of M. We found the frequency and linkage of M in house
 flies collected in Chino, CA (USA) was relatively unchanged between 1982
 and 2014. The frequency of females with Md-traD in the 2014 collection was
 33.6% (n=140). Analysis of these results, plus previously published data,
 revealed a strong correlation between the frequencies of Md-traD and
 multiple M males, and we find that these populations are expected to have
 balanced sex ratios. We also find that fitness values that allow for the
 invasion and maintenance of multiple sex determining loci suggest that
 sexually antagonistic selection could be responsible for maintaining
 polygenic sex determination in house fly populations. The stability over
 time and equilibrium frequencies within populations suggest the house fly
 polygenic sex determination system is not in transition, and provide
 guidance for future investigations on the factors responsible for the
 polymorphism.
description: Random mating
 simulationsThese R commands will
 perform simulations of the Chino, NC, and NY populations without
 selection. Commands are also given for plotting the simulation results,
 reproducing the figures in the manuscript.chino-recursions_2016_08_08.RSelection simulations with fitness assigned at the genotype levelThis python script simulates a population with random mating and selection. Fitness values are randomly assigned to each genotype. The script can be run in parallel on multiple processors, assigned on the command line. The script appends new simulation results to existing simulations that have the same jobID.sim_Dryad.pySimulations with selection coefficients assigned to allelesThis perl script runs simulations of populations with natural selection. Recursions are used to simulate a population with non-overlapping generations. Selection coefficients are randomly assigned to the III^M and Y^M chromosomes in males and females, and to the Md-tra^D allele in females. From these selection coefficients, genotype fitness values are calculated assuming additive interactions of the selection coefficients within and between loci.chino_recursions_seln-allele_dryad.plExpected time to fixationThese R commands estimate the expected time to fixation of sex determining variants due to genetic drift, and also plot graphs to reproduce those published in the manuscript.drift_fixation_2016_08_08.RInitial genotype frequencies for simulations and analysesThese archive contains files needed to run simulations and analyses. Each file has genotype frequencies that are needed for some of the scripts in this Dryad submission.initial_freqs.zipPartial sequence of Md-tra with extra tra/tra2 binding site.Md-tra females vs Multi-M malesThis table contains the frequency of multi-M males and Md-tra^D females from previously published results and data published in this paper.Md-tra_Multi-M_data.tsv