Linkage disequilibrium and recent selection at three immunity receptor loci in Drosophila simulans.
Genetics
; 169(4): 2013-22, 2005 Apr.
Article
em En
| MEDLINE
| ID: mdl-15654108
ABSTRACT
Immune system genes in a California population sample of Drosophila simulans were shown to bear several hallmarks of the effects of past directional selection. One potential effect of directional selection is an increase in linkage disequilibrium among the polymorphic sites that are linked to the site under selection. In this study, we focus on three D. simulans immunity loci, Hmu, Sr-CI/Sr-CIII, and Tehao, for which the polymorphic sites are in nearly perfect linkage disequilibrium, an unusual finding even with respect to other immunity genes sampled from the same lines. The most likely explanation for this finding is that, at each locus, two divergent alleles have been selected to intermediate frequencies in the recent past. The extent to which the linkage disequilibrium extends to the flanks of each of the immunity genes is minimal, suggesting that the favored mutations actually occurred within the immunity genes themselves. Furthermore, the excess linkage disequilibrium found in the California population is not found in an African D. simulans population sample and may be a result of novel pathogen-mediated selection pressures encountered during establishment of non-African populations.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glicoproteínas de Membrana
/
Receptores Imunológicos
/
Desequilíbrio de Ligação
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Receptores de Superfície Celular
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Proteínas de Drosophila
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Drosophila melanogaster
/
Sistema Imunitário
/
Mucinas
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Genetics
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Estados Unidos