DOI: 10.5061/dryad.8931zcrxn
title: Limited associations between MHC diversity and reproductive success in a bird species with biparental care

description: The selective pressure from pathogens on individuals can have direct
 consequences on reproduction. Genes from the major histocompatibility
 complex (MHC) are central to the vertebrate adaptive immune system and
 pathogen resistance. In species with biparental care, each sex has
 distinct reproductive roles and levels of investment, and due to a
 trade-off with immunity, one can expect different selective regimes acting
 upon the MHC of each parent. Here, we addressed whether couples combine
 each other’s variation at MHC loci to increase their breeding success.
 Specifically, we used a 23-year dataset from a barn owl population (Tyto
 alba) to understand how MHC class Iα and IIβ functional divergence and
 supertypes of each parent were associated with clutch size and fledging
 success. We did not detect associations between MHC diversity or
 supertypes with the clutch size nor with the fledging success. In
 addition, to understand the relative contribution from the MHC of the
 genetic parents and the social parents, we analysed the fledging success
 using only a cross-fostered dataset. We found several associations of
 weak-to-moderate effect sizes between the father’s MHC and fledging
 success: i) lower MHC-Iα divergence in the genetic father increases
 fledging success, which might improve paternal care during incubation, and
 ii) one and two MHC-IIβ DAB2 supertypes in the social father decrease and
 increase, respectively, fledging success, which may affect the paternal
 care after hatching. Furthermore, fledging success increased when both
 parents did not carry MHC-IIβ DAB1 supertype 2, which could suggest
 conditional effects of this supertype. Although our study relied on a
 substantial dataset, we showed that the associations between MHC diversity
 and reproductive success remain scarce and of complex interpretation in
 the barn owl. Moreover, our results highlighted the need to incorporate
 more than one proxy of reproductive success and several MHC classes to
 capture more complex associations.
description: # Limited associations between MHC diversity and reproductive success in a
 bird species with biparental care
 R scripts and .csv files
 used to model the response of reproductive success (clutch size and
 fledging success) to MHC diversity (functional divergence and presence of
 the most common supertypes) of a wild barn owl population. Sample size
 might vary between files due to missing genotypes. ## Description of the
 data and file structure Info_file: description of files and variables.
 xxxx_alleles_fasta.fas: fasta files of the alleles present in this barn
 owl population. Accession numbers can be found in the supplementary
 material. Dataset_xxxx_fdiv/supertypes_all_dataset.csv: files containing
 the entire dataset used to test the variation in the clutch size and
 fledging success of each breeding attempt in response to MHC variables and
 covariates. Dataset_xxxx_fdiv/supertypes_full_cross-foster.csv: files
 containing the cross-fostered dataset used to test the variation in the
 fledging success of each breeding attempt and differentiate between
 genetic and parental effects of the MHC of the genetic and social parents
 and respective covariates. ## Code/Software R Scripts:
 1.R_script_fdiv_all_dataset.R: script used to model the clutch size and
 fledging success in response to MHC functional divergence of the parents
 using all dataset. 5.R_script_fdiv_full_cross-foster.R: script used to
 model the clutch size and fledging success in response to MHC functional
 divergence of the genetic and social parents using the cross-fostered
 dataset. 9.R_script_MHC_supertypes_all_dataset.R: script used to model the
 clutch size and fledging success in response to specific MHC supertypes of
 the parents using all dataset.
 13.R_script_MHC_supertypes_full_cross-fostered.R: script used to model the
 clutch size and fledging success in response to specific MHC supertypes of
 the genetic and social parents using the cross-fostered dataset.