| 1. |
- Ekblom, Robert, et al.
(författare)
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Major histocompatibility complex variation and mate choice in a lekking bird, the great snipe (Gallinago media)
- 2004
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 13:12, s. 3821-3828
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Tidskriftsartikel (refereegranskat)abstract
- Genes of the major histocompatibility complex (MHC) play a major part in the activation of the vertebrate immune system. In addition, they also appear to function as cues for mate choice. In mammals especially, several kinds of MHC-dependent mate choice have been hypothesized and observed. These include choice of mates that share no or few alleles with the choosing individual, choice of mates with alleles that differ as much as possible from the choosing individual, choice of heterozygous mates, choice of certain genotypes and choice of rare alleles. We investigated these different aspects of mate choice in relation to MHC in a lekking bird species, the great snipe (Gallinago media). We found no evidence for MHC disassortative mating, no preference for males with many MHC alleles and no preference for rare alleles. However, we did find that some allelic lineages were more often found in males with mating success than in males without mating success. Females do not seem to use themselves as references for the MHC-dependent mate choice, rather they seem to prefer males with certain allele types. We speculate that these alleles may be linked to resistance to common parasites.
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| 2. |
- Ekblom, Robert, et al.
(författare)
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Patterns of polymorphism in the MHC class II of a non-passerine bird, the great snipe (Gallinago media)
- 2003
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Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 54:10, s. 734-741
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Tidskriftsartikel (refereegranskat)abstract
- The genomic organisation of the major histocompatibility complex (MHC) seems to vary considerably between different bird species. In order to understand this variation it is important to gather information from different species. We have, for the first time, investigated MHC class 11 polymorphism in a wader species, the great snipe (Gallinago media). Eleven alleles were found in five sequenced individuals; these come from at least three different loci, but RFLP data suggest that a larger number of genes may be present. For MHC genes, amino acid substitutions followed the, for MHC genes, general pattern of high non-synonymous substitution rates in peptide-binding regions, suggesting that the sequenced alleles may be expressed. The number of genes, lengths of introns and exon sequences of the great snipe MHC seem to be intermediate between those of chicken and passerine birds.
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| 3. |
- Ekblom, Robert, et al.
(författare)
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Spatial pattern of MHC class II variation in the great snipe (Gallinago media)
- 2007
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 16:7, s. 1439-1451
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Tidskriftsartikel (refereegranskat)abstract
- The genes of the major histocompatibility complex (MHC) code for proteins involved in antigen recognition and triggering of the adaptive immune response, and are therefore likely to be under selection from parasites. These selection regimes may vary in space and time. Here we report a strong geographical structure in MHC class II B genes of a migrating bird, the great snipe (Gallinago media). Genetic differentiation in the MHC between two ecologically distinct distributional regions (Scandinavian mountain populations vs. East European lowland populations) was still present after statistically controlling for the effect of selectively neutral variation (microsatellites) using partial Mantel tests. This suggests a role for selection in generating this spatial structure and that it represents local adaptation to different environments. Differentiation between populations within the two regions was negligible. Overall, we found a high number of MHC alleles (50, from 175 individuals). This, together with a tendency for a higher rate of nonsynonymous than synonymous substitutions in the peptide binding sites, and high Tajima's D in certain regions of the gene, suggests a history of balancing selection. MHC variation is often thought to be maintained by some form of balancing selection, but the nature of this selection remains unclear. Our results support the hypothesis that spatial variation in selection regimes contributes to the high polymorphism.
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