Species-specific differences in tissue-specific expression of alcohol dehydrogenase are under the control of complex cis-acting loci: Evidence from Drosophila hybrids

Differences in the expression of alcohol dehydrogenase in the hindgut and testis of adultDrosophila virilis, D. texana, D. novamexicana andD. borealis flies were observed. These heritable differences do not arise due to chromosomal rearrangements, since the polytene chromosome banding patterns did not reveal any such gross chromosomal rearrangements near theAdh locus in any of the tested species. Analysis of the interspecific hybrids revealed that these differences are controlled by complexcis-acting genetic loci. Further, thecis-acting locus controlling the expression of ADH in testis was found to be separable by crossing-over