DOI: 10.5061/dryad.wh70rxwwb
title: Correlated evolution of oxidative physiology and MHC-based immunosurveillance in birds

description: Maintenance and activation of the immune system incurs costs, not only in
 terms of substrates and energy, but also via collateral oxidative damage
 to host cells or tissues during immune response. So far, associations
 between immune function and oxidative damage have been primarily
 investigated at intra-specific scales. Here, we hypothesized that
 pathogen-driven selection should favour evolution of effective
 immunosurveillance mechanisms (e.g. Major Histocompatibility Complex, MHC)
 and antioxidant defences to mitigate oxidative damage resulting from
 immune function. Using phylogenetically-informed comparative approaches,
 we provided evidence for correlated evolution of host oxidative physiology
 and MHC-based immunosurveillance in birds. Species selected for more
 robust MHC-based immunosurveillance (higher gene copy numbers and allele
 diversity) showed stronger antioxidant defences, although selection for
 MHC diversity still showed a positive evolutionary association with
 oxidative damage to lipids. Our results indicate that historical
 pathogen-driven selection for highly duplicated and diverse MHC could have
 promoted the evolution of efficient antioxidant mechanisms, but these
 evolutionary solutions may be insufficient to keep oxidative stress at
 bounds. Although the precise nature of mechanistic links between the MHC
 and oxidative stress remains unclear, our study suggests that a general
 evolutionary investment in immune function may require co-adaptations at
 the level of host oxidative metabolism.
description: # Title of Dataset: Correlated evolution of oxidative physiology and
 MHC-based immunosurveillance in birds --- ## Description of the data and
 file structure Minias_et_al_species_DATA.xlsx file contains
 species-specific data used in the phylogenetically-informed comparative
 analyses of oxidative physiology and Major Histocompatibility (MHC) genes.
 MHC_gene_copy_number spreadsheet contains data used for the analyses of
 MHC gene copy number variation (n = 50 species), including information on:
 1. Species 2. TAS_mean - mean total antioxidant status 3. TAS_corrected_UA
 - total antioxidant status corrected for variation in uric acid (best
 linear unbiased estimate) 4. TAS_corrected_year - total antioxidant status
 corrected for between-year variation (best linear unbiased estimate) 5.
 TAS_n - sample size for total antioxidant status (number of individuals
 measured) 6. UA_mean - mean uric acid 7. UA_corrected_year - uric acid
 corrected for between-year variation (best linear unbiased estimate) 8.
 UA_n - sample size for uric acid (number of individuals measured) 9.
 tGSH_mean - mean total glutathione 10. tGSH_n - sample size for total
 glutathione (number of individuals measured) 11. MDA_mean - mean
 malondialdehyde 12. MDA_n - sample size for malondialdehyde (number of
 individuals measured) 13. ROMs_mean - mean reactive oxygen metabolites 14.
 ROMs_n - sample size for reactive oxygen metabolites (number of
 individuals measured) 15. MHC_copy_number - mean number of functional
 MHC-I/MHC-II genes 16. MHC_copy_number_log - log z-transformed number of
 functional MHC-I/MHC-II genes 17. Body_mass (g) 18. Clutch_size (number of
 eggs) 19. Residual_lifespan - residual of maximum lifespan (years) against
 source of data (wild-living vs. captivity), sampling effort, and body mass
 20. Diet Selection_for_MHC-I_diversity spreadsheet contains data used for
 the analyses of selection for MHC-I diversity (n = 28 species), including
 information on: 1. Species 2. TAS_mean - mean total antioxidant status 3.
 TAS_corrected_UA - total antioxidant status corrected for variation in
 uric acid (best linear unbiased estimate) 4. TAS_corrected_year - total
 antioxidant status corrected for between-year variation (best linear
 unbiased estimate) 5. TAS_n - sample size for total antioxidant status
 (number of individuals measured) 6. UA_mean - mean uric acid 7.
 UA_corrected_year - uric acid corrected for between-year variation (best
 linear unbiased estimate) 8. UA_n - sample size for uric acid (number of
 individuals measured) 9. tGSH_mean - mean total glutathione 10. tGSH_n -
 sample size for total glutathione (number of individuals measured) 11.
 MDA_mean - mean malondialdehyde 12. MDA_corrected_TAS - malondialdehyde
 corrected for variation in total antioxidant status (best linear unbiased
 estimate) 13. MDA_corrected_UA - malondialdehyde corrected for variation
 in uric acid (best linear unbiased estimate) 14. MDA_corrected_year -
 malondialdehyde corrected for between-year variation (best linear unbiased
 estimate) 15. MDA_n - sample size for malondialdehyde (number of
 individuals measured) 16. ROMs_mean - mean reactive oxygen metabolites 17.
 ROMs_n - sample size for reactive oxygen metabolites (number of
 individuals measured) 18. Residual_dN_human_PBR - residuals of
 dN_human_PBR against dS_human_PBR 19. dN_human_PBR - non-synonymous
 nucleotide substitution rate across human peptide-binding residues (PBR)
 at the MHC-I exon 3 20. dS_human_PBR - synonymous nucleotide substitution
 rate across human peptide-binding residues (PBR) at the MHC-I exon 3 21.
 Residual_dN_bird_PSS - residuals of dN_bird_PSS against dS_bird_PSS 22.
 dN_bird_PSS - non-synonymous nucleotide substitution rate across 20 most
 positively selected sites (PSS) at the MHC-I exon 3 23. dS_bird_PSS -
 synonymous nucleotide substitution rate across 20 most positively selected
 sites (PSS) at the MHC-I exon 3 24. Body_mass (g) 25. Clutch_size (number
 of eggs) 26. Residual_lifespan - residual of maximum lifespan (years)
 against source of data (wild-living vs. captivity), sampling effort, and
 body mass 27. Diet Minias_et_al_sequence_DATA.fasta file contains sequence
 data (n = 1777 sequences) used to quantify non-synonymous (dN) and
 synonymous (dS) nucleotide substitution rates at the MHC-I (n = 28
 species). All sequences were retrieved from GenBank NCBI database. GenBank
 number and species are provided for each sequence.
 Minias_et_al_tree_DATA.phy file contains consensus phylogenetic tree (n =
 50 species) generated across a random sample of 1000 alternative trees
 retrieved from the BirdTree webserver
 ([http://www.birdtree.org](http://www.birdtree.org)). ## Sharing/Access
 information Not applicable ## Code/Software Minias_et_al_code.txt file
 contains R code used for the phylogenetically-informed comparative
 analyses of oxidative physiology and Major Histocompatibility (MHC) genes.