Evidence of the adaptive evolution of immune genes in chicken

被引：15

作者：

Downing T. ^{[1
,2
]}

Cormican P. ^{[3
,4
]}

O'Farrelly C. ^{[3
]}

Bradley D.G. ^{[1
]}

Lloyd A.T. ^{[3
]}

机构：

[1] Smurfit Institute of Genetics, Trinity College, University of Dublin

[2] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton

[3] School of Biochemistry and Immunology, Trinity College, University of Dublin

[4] Institute of Molecular Medicine, Trinity College, University of Dublin

来源：

BMC Research Notes | / 2卷 / 1期

关键词：

Adaptive Evolution; Zebra Finch; Immune Gene; Fixation Index; Nonsynonymous Mutation;

D O I：

10.1186/1756-0500-2-254

中图分类号：

学科分类号：

摘要：

The basis for understanding the characteristics of gene functional categories in chicken has been enhanced by the ongoing sequencing of the zebra finch genome, the second bird species to be extensively sequenced. This sequence provides an avian context for examining how variation in chicken has evolved since its divergence from its common ancestor with zebra finch as well as well as a calibrating point for studying intraspecific diversity within chicken. Immune genes have been subject to many selective processes during their evolutionary history: this gene class was investigated here in a set of orthologous chicken and zebra finch genes with functions assigned from the human ortholog. Tests demonstrated that nonsynonymous sites at immune genes were highly conserved both in chicken and on the avian lineage. McDonald-Kreitman tests provided evidence of adaptive evolution and a higher rate of selection on fixation of nonsynonymous substitutions at immune genes compared to that at non-immune genes. Further analyses showed that GC content was much higher in chicken than in zebra finch genes, and was significantly elevated in both species' immune genes. Pathogen challenges are likely to have driven the selective forces that have shaped variation at chicken immune genes, and continue to restrict diversity in this functional class. © 2009 Lloyd et al.

引用

共 30 条

[1]

Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution, Nature, 432, pp. 695-716, (2004)

[2]

Schlenke T.A., Begun D.J., Natural selection drives Drosophila immune system evolution, Genetics, 164, 4, pp. 1471-80, (2003)

[3]

Hughes A.L., Packer B., Welch R., Chanock S.J., Yeager M., High level of functional polymorphism indicates a unique role of natural selection at human immune system loci, Immunogenetics, 57, 11, pp. 821-7, (2005)

[4]

Ellegren H., Molecular evolutionary genomics of birds, Cytogenet Genome Res, 117, 1-4, pp. 120-30, (2007)

[5]

Andreozzi L., Federico C., Motta S., Saccone S., Sazanova A.L., Sazanov A.A., Smirnov A.F., Galkina S.A., Lukina N.A., Rodionov A.V., Carels N., Bernardi G., Compositional mapping of chicken chromosomes and identification of the gene-richest regions, Chromosome Res, 9, pp. 521-32, (2001)

[6]

Webster M.T., Axelsson E., Ellegren H., Strong regional biases in nucleotide substitution in the chicken genome, Mol Biol Evol, 23, pp. 1203-16, (2006)

[7]

Costantini M., Di Filippo M., Auletta F., Bernardi G., Isochore pattern and gene distribution in the chicken genome, Gene, 400, pp. 9-15, (2007)

[8]

Organ C.L., Shedlock A.M., Meade A., Pagel M., Edwards S.V., Origin of avian genome size and structure in non-avian dinosaur, Nature, 446, pp. 180-4, (2007)

[9]

Hughes A.L., Hughes M.K., Small genomes for better flyers, Nature, 377, (1995)

[10]

A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms, Nature, 432, pp. 717-22, (2004)

← 1 2 3 →