DOI: 10.5061/dryad.26k11
title: Data from: Sexual selection and the evolution of the Major Histocompatibility Complex

description: The genes of the major histocompatibility complex (MHC) are a key
 component of the adaptive immune system and among the most variable loci
 in the vertebrate genome. Pathogen-mediated natural selection and
 MHC-based disassortative mating are both thought to structure MHC
 polymorphism, but their effects have proven difficult to discriminate in
 natural systems. Using the first model of MHC dynamics incorporating both
 survival and reproduction, we demonstrate that natural and sexual
 selection produce distinctive signatures of MHC allelic diversity with
 critical implications for understanding host–pathogen dynamics. While
 natural selection produces the Red Queen dynamics characteristic of
 host–parasite interactions, disassortative mating stabilizes allele
 frequencies, damping major fluctuations in dominant alleles and protecting
 functional variants against drift. This subtle difference generates a
 complex interaction between MHC allelic diversity and population size. In
 small populations, the stabilizing effects of sexual selection moderate
 the effects of drift, whereas pathogen-mediated selection accelerates the
 loss of functionally important genetic diversity. Natural selection
 enhances MHC allelic variation in larger populations, with the highest
 levels of diversity generated by the combined action of pathogen-mediated
 selection and disassortative mating. MHC-based sexual selection may help
 to explain how functionally important genetic variation can be maintained
 in populations of conservation concern.
description: Data files (Matlab
 worksapces) packed in a ZIP archive - scenarios with no
 pathogensScenarios with no
 interaction between pathogens and hosts Data set is packed in a ZIP
 archive. Names of catalogue in the archive indicate scenario parameters:
 host population size N and simulated mechanism of partner choice (RM -
 random mating, h0 - soft assortative mating, h1 - hard assortative mating;
 see Materials and Methods for details). Each scenario catalogue contains
 100 files (Matlab workspaces) with saved variables of each of 100
 independent replications. Saved variables: HED_scen – partner choice
 scenario (random mating HED_scen=NaN, soft assortative mating h0
 HED_scen=0, hard assortative mating h1 HED_scen=1) N – host population
 size off_val_occ – offspring reproductive value at birth in subsequent
 mating attempts h_mut_rat – host mutation rate host_n_all – allelic
 richness across generations host_time – host generation number
 mat_occ_distr – number of mating pairs in subsequent mating attempts
 (first row indicate first mating attempt) saved every host generation
 Compl_all_hist – frequency distribution of MHC alleles saved in last 1400
 host generations (host generations 1600-3000). Matrix of allele frequency
 distribution is saved as Matlab sparse matrix, (type full(Compl_all_hist)
 to transform Compl_all_hist into trajectories of allele frequency)
 in_pres_al – decimal labels of MHC alleles in allele frequency history
 matrix Compl_all_histPathogens_off.zipData files (Matlab worksapces) packed in a ZIP archive - scenarios with pathogens, mutation rate 1*10^-3Scenarios in which pathogens interact with hosts Data set is packed in a ZIP archive. Names of catalogue in the archive indicate scenario parameters: host population size N and simulated mechanism of partner choice (RM - random mating, h0 - soft assortative mating, h1 - hard assortative mating; see Materials and Methods for details). Each scenario catalogue contains 100 files (Matlab workspaces) with saved variables of each of 100 independent replications. Saved variables: HED_scen – partner choice scenario (random mating HED_scen=NaN, soft assortative mating h0 HED_scen=0, hard assortative mating h1 HED_scen=1) N – host population size off_val_occ – offspring reproductive value at birth in subsequent mating attempts h_mut_rat – host mutation rate bits_num – number of bits in MHC molecule match – number of matching bits necessary for antigen presentation num_pat_spec – number of pathogen species p_mut_rat – pathogen mutation rate pat_gen – number of pathogen generations per one host generation pept_num – number of antigens produced by a pathogen host_n_all – allelic richness across generations host_time – host generation number mat_occ_distr – number of mating pairs in subsequent mating attempts (first row indicate first mating attempt) saved every host generation Compl_all_hist – frequency distribution of MHC alleles saved in last 1400 host generations (host generations 1600-3000). Matrix of allele frequency distribution is saved as Matlab sparse matrix, (type full(Compl_all_hist) to transform Compl_all_hist into trajectories of allele frequency) in_pres_al – decimal labels of MHC alleles in allele frequency history matrix Compl_all_hist mean_pres_pat – mean proportion of presented pathogens SD_pres_pat – standard deviation for the proportion of presented pathogensPathogens_on_1x10min3.zipData files (Matlab worksapces) packed in a ZIP archive - scenarios with pathogens, mutation rate 2*10^-3Scenarios in which pathogens interact with hosts Data set is packed in a ZIP archive. Names of catalogue in the archive indicate scenario parameters: host population size N and simulated mechanism of partner choice (RM - random mating, h0 - soft assortative mating, h1 - hard assortative mating; see Materials and Methods for details). Each scenario catalogue contains 100 files (Matlab workspaces) with saved variables of each of 100 independent replications. Saved variables: HED_scen – partner choice scenario (random mating HED_scen=NaN, soft assortative mating h0 HED_scen=0, hard assortative mating h1 HED_scen=1) N – host population size off_val_occ – offspring reproductive value at birth in subsequent mating attempts h_mut_rat – host mutation rate bits_num – number of bits in MHC molecule match – number of matching bits necessary for antigen presentation num_pat_spec – number of pathogen species p_mut_rat – pathogen mutation rate pat_gen – number of pathogen generations per one host generation pept_num – number of antigens produced by a pathogen host_n_all – allelic richness across generations host_time – host generation number mat_occ_distr – number of mating pairs in subsequent mating attempts (first row indicate first mating attempt) saved every host generation Compl_all_hist – frequency distribution of MHC alleles saved in last 1400 host generations (host generations 1600-3000). Matrix of allele frequency distribution is saved as Matlab sparse matrix, (type full(Compl_all_hist) to transform Compl_all_hist into trajectories of allele frequency) in_pres_al – decimal labels of MHC alleles in allele frequency history matrix Compl_all_hist mean_pres_pat – mean proportion of presented pathogens SD_pres_pat – standard deviation for the proportion of presented pathogensPathogens_on_2x10min3.zipData files (Matlab worksapces) packed in a ZIP archive - scenarios with pathogens, mutation rate 5*10^-3Scenarios in which pathogens interact with hosts Data set is packed in a ZIP archive. Names of catalogue in the archive indicate scenario parameters: host population size N and simulated mechanism of partner choice (RM - random mating, h0 - soft assortative mating, h1 - hard assortative mating; see Materials and Methods for details). Each scenario catalogue contains 100 files (Matlab workspaces) with saved variables of each of 100 independent replications. Saved variables: HED_scen – partner choice scenario (random mating HED_scen=NaN, soft assortative mating h0 HED_scen=0, hard assortative mating h1 HED_scen=1) N – host population size off_val_occ – offspring reproductive value at birth in subsequent mating attempts h_mut_rat – host mutation rate bits_num – number of bits in MHC molecule match – number of matching bits necessary for antigen presentation num_pat_spec – number of pathogen species p_mut_rat – pathogen mutation rate pat_gen – number of pathogen generations per one host generation pept_num – number of antigens produced by a pathogen host_n_all – allelic richness across generations host_time – host generation number mat_occ_distr – number of mating pairs in subsequent mating attempts (first row indicate first mating attempt) saved every host generation Compl_all_hist – frequency distribution of MHC alleles saved in last 1400 host generations (host generations 1600-3000). Matrix of allele frequency distribution is saved as Matlab sparse matrix, (type full(Compl_all_hist) to transform Compl_all_hist into trajectories of allele frequency) in_pres_al – decimal labels of MHC alleles in allele frequency history matrix Compl_all_hist mean_pres_pat – mean proportion of presented pathogens SD_pres_pat – standard deviation for the proportion of presented pathogensPathogens_on_5x10min3.zip