Insertion of the retroposable element,jockey, near theAdhgene ofDrosophila melanogasteris associated with altered gene expression

Abstract

SummaryThealcohol dehydrogenase(Adh) gene ofDrosophila melanogasteris well suited to be a gene expression reporter system.Adhproduces a measurable phenotype at both the enzyme and mRNA levels. We recovered a spontaneous transposable element (TE) insertion mutation near theAdhgene. The insertion is a truncated retroposable element,jockey, inserted upstream of the adultAdhenhancer region. Comparisons between theAdhjockeyallele and its direct wild-type ancestral allele were made in an isogenic background (i.e. identicalcisandtransfactors). Differences inAdhjockeyexpression compared with the wild-type can be attributed solely to the presence of thejockeyelement. Thisjockeyinsertion results in a decrease in adult mRNA transcript levels in theAdhjockeyhomozygous lines relative to the wild-type counterpart and accounts for a correlated decrease in alcohol dehydrogenase (ADH) enzyme activity. The larval ADH activity levels are not detectably different.