Analysis of linkage disequilibria between allozyme loci in natural populations of<i>Drosophila melanogaster</i>

Abstract

SUMMARY Linkage disequilibria between pairs of 8 polymorphic enzyme loci (α Gpdh, Mdh, Adh, Est-6, Pgm, Odh, Est-C and Acph ) in some 100 natural population samples of Drosophila melanogaster were examined. The estimates of linkage disequilibrium were made from zygotic frequencies. The magnitude of linkage disequilibria are small and similar to those in previous reports. Variation in linkage disequilibrium among related subpopulations was analysed by analysis of variance of the correlation coefficients. Despite the small absolute value of linkage disequilibrium there is a suggestion of a correlation among related subpopulations. The magnitude of linkage disequilibrium was observed to be positively correlated with linkage. Two cage populations were observed to demonstrate large amounts of linkage disequilibrium between closely linked loci in contrast to the situation in natural populations. This is attributable to the finite sizes of these cage populations.