The effect of chromosomal position on the expression of the Drosophila xanthine dehydrogenase gene.
Thirty-six isogenic D. melanogaster strains that differed only in the chromosomal location of a 7.2 or an 8.1 kb DNA segment containing the (autosomal) rosy gene were constructed by P-element-mediated gene transfer. Since the flies were homozygous for a rosy- allele, rosy gene function in these indicated the influence of flanking sequences on gene expression. The tissue distribution of XDH activity in all the strains was normal. Each line exhibited a characteristic level of adult XDH-specific activity. The majority of these values were close to wild-type levels; however, the total variation in specific activity among the lines was nearly fivefold. Thus position effects influence expression of the rosy gene quantitatively but do not detectably alter tissue specificity. X-linked rosy insertions were expressed on average 1.6 times more activity in males than in females. Hence the gene acquires at least partial dosage compensation upon insertion into the X chromosome.
D000818:Animals; D002875:Chromosomes / Q000502:physiology*; D004251:DNA Transposable Elements; D004303:Dosage Compensation, Genetic; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D007658:Ketone Oxidoreductases / Q000235:genetics*; D014018:Tissue Distribution; D014170:Transformation, Genetic; D014960:X Chromosome; D014968:Xanthine Dehydrogenase / Q000235:genetics* / Q000378:metabolism
D004251:DNA Transposable Elements; D014968:Xanthine Dehydrogenase; D007658:Ketone Oxidoreductases