Struktura MHC a jeho vliv na pohlavní výběr monogamního zástupce hrabavých, koroptve polní
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Year of publication | 2013 |
Type | Appeared in Conference without Proceedings |
Citation | |
Description | Major histocompatibility complex (MHC) genes are one of the basic components of specific immunity of jawed vertebrates. Their products are transmembrane glycoproteins situated on the surface of immune and non-immune cells. With the T lymfocytes they are able to recognize nonself antigens and initiate the adaptive immune response, which creates the essential defence of an organism against pathogens. As the recent extensive research of this region showed, the structure of these highly polymorphic genes such as the mechanisms of their influence on the individual fitness are very different in various groups of vertebrates, especially in birds. Big differences occur not only between various orders (e.g. chicken, Galliformes vs. scarlet rosefinch, Passeriformes), but also within one taxon (e.g. in Galliformes, chicken vs. Japanese quail). In this work we focused on monogamous galliform bird, the Grey partridge (Perdix perdix). We genotyped the polymorphic part of MHC class IIB gene (exon 2) by SSCP method; this part encodes the region for antigen binding on MHC glycoprotein. We described the MHC IIB structure, its individual and population variability, and historical selection acting on this gene. Furthermore, we analyzed the influence of MHC IIB variability on individual fitness and sexual selection in captive and free-ranging population. At least two loci of MHC class IIB gene were found in the Grey partridge (from two to four different exon 2 variants per individual), both putatively functional. Isolation of 12 alleles from 108 individuals shows the medium level of intrapopulation polymorphism. The analyses proved the strong historical selection affecting the MHC IIB genes and at the same time discovered at least two points of recombination and tracks of gene conversion. We found the connection of MHC genes and fitness in the captive population, but their relationship in the free-ranging population is still ambiguous. The results contribute to better recognition of MHC genes in birds, including the mechanisms of their impact, and simultaneously to understanding the evolution of immune genes in birds, especially in Galliformes. |
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