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The Evolution of Highly Variable Immunity Genes Across a Passerine Bird Radiation

O'Connor, Emily LU ; Strandh, Maria LU ; Hasselquist, Dennis LU ; Nilsson, Jan-Åke LU and Westerdahl, Helena LU (2016) In Molecular Ecology
Abstract
In order to survive, individuals must be able to recognise and eliminate pathogens. The genes of the Major Histocompatibility Complex (MHC) play an essential role in this process in vertebrates as their diversity affects the repertoire of pathogens that can be recognised by the immune system. Emerging evidence suggests that birds within the parvorder Passerida possess an exceptionally high number of MHC genes. However, this has yet to be directly investigated using a consistent framework, and the question of how this MHC diversity has evolved has not been addressed. We used next generation sequencing to investigate how MHC class I gene copy number and sequence diversity varies across the Passerida radiation using twelve species chosen to... (More)
In order to survive, individuals must be able to recognise and eliminate pathogens. The genes of the Major Histocompatibility Complex (MHC) play an essential role in this process in vertebrates as their diversity affects the repertoire of pathogens that can be recognised by the immune system. Emerging evidence suggests that birds within the parvorder Passerida possess an exceptionally high number of MHC genes. However, this has yet to be directly investigated using a consistent framework, and the question of how this MHC diversity has evolved has not been addressed. We used next generation sequencing to investigate how MHC class I gene copy number and sequence diversity varies across the Passerida radiation using twelve species chosen to represent the phylogenetic range of this group. Additionally, we performed phylogenetic analyses on this data to identify, for the first time, the evolutionary model that best describes how MHC class I gene diversity has evolved within Passerida. We found evidence of multiple MHC class I genes in every family tested, with an extremely broad range in gene copy number across Passerida. There was a strong phylogenetic signal in MHC gene copy number and diversity, and these traits appear to have evolved through a process of Brownian Motion in the species studied, i.e. following the pattern of genetic drift or fluctuating selection, as opposed to towards a single optimal value or through evolutionary ‘bursts’. By characterising MHC class I gene diversity across Passerida in a systematic framework, this study provides a first step towards understanding this huge variation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Class I, Major Histocompatibility Complex, Diversity, Evolutionary Model, Birds.
in
Molecular Ecology
publisher
Wiley-Blackwell
external identifiers
  • pmid:26757248
  • scopus:84958279286
  • wos:000370653700011
ISSN
0962-1083
DOI
10.1111/mec.13530
project
Avian MHC genes
language
English
LU publication?
yes
id
dabcf7a4-0e96-45d2-bf64-067a5c09dd1f (old id 8521269)
date added to LUP
2016-02-09 14:32:08
date last changed
2017-08-06 03:08:37
@article{dabcf7a4-0e96-45d2-bf64-067a5c09dd1f,
  abstract     = {In order to survive, individuals must be able to recognise and eliminate pathogens. The genes of the Major Histocompatibility Complex (MHC) play an essential role in this process in vertebrates as their diversity affects the repertoire of pathogens that can be recognised by the immune system. Emerging evidence suggests that birds within the parvorder Passerida possess an exceptionally high number of MHC genes. However, this has yet to be directly investigated using a consistent framework, and the question of how this MHC diversity has evolved has not been addressed. We used next generation sequencing to investigate how MHC class I gene copy number and sequence diversity varies across the Passerida radiation using twelve species chosen to represent the phylogenetic range of this group. Additionally, we performed phylogenetic analyses on this data to identify, for the first time, the evolutionary model that best describes how MHC class I gene diversity has evolved within Passerida. We found evidence of multiple MHC class I genes in every family tested, with an extremely broad range in gene copy number across Passerida. There was a strong phylogenetic signal in MHC gene copy number and diversity, and these traits appear to have evolved through a process of Brownian Motion in the species studied, i.e. following the pattern of genetic drift or fluctuating selection, as opposed to towards a single optimal value or through evolutionary ‘bursts’. By characterising MHC class I gene diversity across Passerida in a systematic framework, this study provides a first step towards understanding this huge variation.},
  author       = {O'Connor, Emily and Strandh, Maria and Hasselquist, Dennis and Nilsson, Jan-Åke and Westerdahl, Helena},
  issn         = {0962-1083},
  keyword      = {Class I,Major Histocompatibility Complex,Diversity,Evolutionary Model,Birds.},
  language     = {eng},
  month        = {02},
  publisher    = {Wiley-Blackwell},
  series       = {Molecular Ecology},
  title        = {The Evolution of Highly Variable Immunity Genes Across a Passerine Bird Radiation},
  url          = {http://dx.doi.org/10.1111/mec.13530},
  year         = {2016},
}