Molecular characterization of a Drosophila melanogaster variant straindefective in the Sgs-4 gene dosage compensation

The X-linked Sgs.4 gone of Drosophila melanogaswr encodes a salivary glue protein. Here we report the molecular characterization of a non.dosage compensated variant strain, named Karsnas, in which males accumulate only about half of the Sgs-4 polypeptidc amount as do females. The results obtained show that significant nucleotide sequence alterations arc accumulated within the Sgs-4 coding and 3' untranslated region of the variant strain, thus suggesting a possible role of these sequences in the Sgs.4 dosage compensation.