Parasite diversity and major histocompatibility complex: the variation in MHC class IIB in six European populations of chub (Leuciscus cephalus Linnaeus, 1758)
| Autoři | |
|---|---|
| Rok publikování | 2007 |
| Druh | Další prezentace na konferencích |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | MHC genes are highly polymorphic and are co-dominantly expressed on cells. Our study was focused on MHC II genes, because they are critical for initiation the immune response against extracellular antigens derived from pathogens and parasites. Polymorphism of these genes is maintained by heterozygote advantage (or overdominance hypothesis), rare-allele advantage (or negative frequency dependent selection hypothesis), and disassortative mating, whereas parasites are likely the important selective agents. An influence of parasite diversity on genetic variability of the host’s MHC molecules, concretely of the exon 2, which encodes the beta 1 domain of the peptide binding region and is the most variable site of MHC II molecules, was examined. In six populations of the chub collected from the Czech Republic and France 83 alleles were found. Between 10 and 26 alleles were identified per population, the minimum number of alleles per fish was one and maximum five alleles. 36 species of parasites, representing 8 higher taxa (Monogenea, Crustacea (parasitic Copepoda), Mollusca, Hirudinea, Digenea, Acantocephala, Nematoda and Cestoda), were identified. The highest abundance, prevalence, and mean intensity of infection were characterized for monogenean species. |
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