Complete absence of linkage disequilibrium between enzyme loci in natural populations of Drosophila ananassae

Abstract

Linkage disequilibrium has been studied among three linked enzyme loci of second chromosome of D. ananassae collected from five natural populations. Each of the three enzyme loci, that is Acph1, Acph 2 and Xdh was represented by two distinct alleles and in three genotypic forms. Thus nine genotypic combinations were recorded for each enzyme pair. The results clearly show absence of non-random occurrence of different genotypic combinations in all the populations studied. The occurrence of all possible genotypic combinations indicates enough frequency of crossing over among these enzyme loci. The absence of linkage disequilibrium in this study thus indicates that selection did not play any role and free recombination among the genes resulted random occurrence of all combinations.