Compensatory aspects of allele diversity at immunoglobulin loci: gene correlations in rabbit populations devoid of light chain diversity (Oryctolagus cuniculus L.; Kerguelen Islands).
Genetics
; 144(3): 1181-94, 1996 Nov.
Article
in En
| MEDLINE
| ID: mdl-8913759
ABSTRACT
Is there a selective advantage of increased diversity at one immunoglobulin locus when diversity at another locus is low? A previous paper demonstrated excess heterozygosity at the rabbit light chain b locus when heterozygosity was low at the heavy chain constant region e locus. Here we consider the reverse situation by analyzing allele distributions at heavy chain loci in populations fixed for the light chain b locus. We analyzed the a locus that encodes the predominantly expressed heavy chain variable region, and the d and e loci that control different parts of the Ig gamma class constant region. While there was excess heterozygosity, genetic differentiation between localities was extensive and was most pronounced for females. This was in marked contrast with observations in areas where b-locus diversity was important and confirms a negative correlation between e- and b-locus heterozygosity. Trigenic disequilibria corresponded to a significant negative correlation between e- and a-locus heterozygosity due mainly to strong variation among localities within the context of pronounced (digenic) linkage disequilibria. Although substantial, the average increase in a/e-locus single heterozygosity implemented by higher order disequilibria within localities was not significant.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Genetic Variation
/
Immunoglobulins
/
Alleles
Limits:
Animals
Language:
En
Journal:
Genetics
Year:
1996
Document type:
Article
Affiliation country:
Belgium