ORGANIZATION OF THE ROSY LOCUS IN DROSOPHILA MELANOGASTER: FURTHER EVIDENCE IN SUPPORT OF A CIS-ACTING CONTROL ELEMENT ADJACENT TO THE XANTHINE DEHYDROGENASE STRUCTURAL ELEMENT

Abstract

The present report summarizes our recent progress in the genetic dissection of an elementary genetic unit in a higher organism, the rosy locus (ry: 3-52.0) in Drosophila melanogaster. Pursuing the hypothesis that the rosy locus includes a noncoding control region, as well as a structural element coding for the xanthine dehydrogenase (XDH) peptide, experiments are described that characterize and map a rosy locus variant associated with much lower than normal levels of XDH activity. Experiments are described that fail to relate this phenotype to alteration in the structure of the XDH peptide, but clearly associate this character with variation in number of molecules of XDH per fly. Large-scale fine-structure recombination experiments locate the genetic basis for this variation in the number of molecules of XDH per fly to a site immediately to the left of the XDH structural element within a region previously designated as the XDH control element. Moreover, experiments clearly separate this "underproducer" variant site from a previously described "overproducer" site within the control region. Examination of enzyme activity in electrophoretic gels of appropriate heterozygous genotypes demonstrates the cis-acting nature of this variation in the number of molecules of XDH. A revision of the map of the rosy locus, structural and control elements is presented in light of the additional mapping data now available.

Differential regulation of duplicate alcohol dehydrogenase genes in Drosophila mojavensis

“…In recent years a substantial amount of information has heen accumulating wh ich indicates t.hat information related to the developmental regulation of genes may be encoded by cis-acting elements which are closely linked to ind ividual structural genes. In Drosoph-ila, examples of this type of element are those which affect the regulation of a lcohol dehydrogenase (Thompson et al, 1977;Dickinson and Carson 1979;Dickinson 1980a,b;Rabinow and Dickinson, 1981), xanthine dehydrogenase (McCarron et al, 1979), and aldehyde oxidase (Dickinson 1975). In addition a number of such elements have been found in mice (reviewed in Paigen, 1979).…”

HIDDEN ELECTROPHORETIC VARIATION AT THE XANTHINE DEHYDROGENASE LOCUS IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER

“…This locus is an appropriate one to screen for evidence of loci affecting protein mobility. There is evidence for a cis-acting control site (i409) for Xdh immediately to the left of the structural gene (CHOVNICK et al 1976;MCCARRON et al 1979). In addition three other loci, low xanthine dehydrogenase (Jxd, 3-33.9), maroon-like (ma-I, 2-64.8) and cinnamon (cin, 1-0.0) also affect XDH activity (MACINTYRE and O'BRIEN 1976).…”