2007
Genetic variability of MHC class IIB genes associated with parasite diversity in European populations of chub (Leuciscus cephalus Linnaeus, 1758)
SEIFERTOVÁ, Mária; Martina VYSKOČILOVÁ; Jiří JARKOVSKÝ a Andrea ŠIMKOVÁZákladní údaje
Originální název
Genetic variability of MHC class IIB genes associated with parasite diversity in European populations of chub (Leuciscus cephalus Linnaeus, 1758)
Vydání
7th International Symposium on Fish Parasites, Viterbo (Italy), 24th – 28th September 2007, 2007
Další údaje
Jazyk
angličtina
Typ výsledku
Prezentace na konferencích
Obor
10600 1.6 Biological sciences
Stát vydavatele
Itálie
Utajení
není předmětem státního či obchodního tajemství
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/07:00041713
Organizační jednotka
Přírodovědecká fakulta
Klíčová slova česky
geny třídy MHC IIB kaprovití selekce polymorfismus
Klíčová slova anglicky
MHC class IIB genes Cyprinidae Selection Polymorphism
Příznaky
Mezinárodní význam
Změněno: 10. 3. 2011 08:49, Mgr. Mária Seifertová, Ph.D.
Anotace
V originále
The genes of the major histocompatibility complex (MHC) are the most polymorphic loci known for vertebrates. The host- pathogen coevolution and parasite-driven balancing selection have a extensive contribution to the high level of allelic diversity in MHC genes. The polymorphism of MHC molecules can be extremely huge; there are a large number of genetic variants (alleles) at each genetic locus. Individuals with higher number of different MHC molecules are able to recognize a broader spectrum of pathogen or parasite derived antigens, and then pathogens or parasites evolve to evade common MHC genotypes, giving rare MHC genotypes a selective advantage. A common European cyprinid, the chub, Leuciscus cephalus (L.), was chosen as a model organism for investigating the hypothesis of pathogen-driven selection under natural conditions, mediated either through heterozygous advantage (overdominant selection) or negative frequency-dependent selection (rare allele advantage hypothesis). There is a prediction that the populations with more genetic variability of MHC will have more diverse array of parasites. Therefore, the aims of this project were: (1) to study the diversity of metazoan parasites and compare the parasite communities of chub in relation to geographic distances between fish populations; (2) to investigate the variability of the exon 2 of MHC class IIB gene corresponding to ß1 domain of this class which includes the most polymorphic part of class II genes, the peptide binding regions (PBR); (3) to analyze fish populations using microsatellite loci, as a neutral marker; (4) to investigate the relationships between MHC, microsatellite variability and parasitism and finally (5) to examine whether the geographic distances and historical associations among localities have influenced the degree of genetic variation. The fish were caught using electrofishing in the selected different localities in Europe including a high range of chub distribution. Basic epidemiological parameters and parasite component community indexes were computed for each fish population. The variability of the exon 2 of DAB genes (MHC class IIB) was analyzed using SSCP, cloning and sequencing. All identified parasite species represent 8 higher metazoan parasite taxa: Monogenea, Crustacea (parasitic Copepoda), Mollusca, Hirudinea, Digenea, Acantocephala, Nematoda and Cestoda. Chub harbored more ectoparasites than endoparasites species. The highest values of abundance, prevalence and mean intensity of infection were observed for monogenean species. The geographical distances among fish populations were associated with microsatellite variability. The results indicated the relationship between MHC allelic diversity and parasite occurrence, i.e. the more parasitized populations of chub (level of parasite infection estimated by Shannon index diversity or Simpson index of dominance) reached the high level of MHC variability. This study was funded by the Grant Agency of the Czech Republic, Project No. 524/04/1128 and Research Project of the Masaryk University, Brno MSM 0021622416.
Návaznosti
| GA524/07/0188, projekt VaV |
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| MSM0021622416, záměr |
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