Mj. Palmer et al., THE MALE-SPECIFIC LETHAL-ONE (MSL-1) GENE OF DROSOPHILA-MELANOGASTER ENCODES A NOVEL PROTEIN THAT ASSOCIATES WITH THE X-CHROMOSOME IN MALES, Genetics, 134(2), 1993, pp. 545-557
male-specific lethal-one (msl-1) is one of four genes that are require
d for dosage compensation in Drosophila males. To determine the molecu
lar basis of msl-1 regulation of dosage compensation, we have cloned t
he gene and characterized its products. The predicted msl-1 protein (M
SL-1) has no significant similarity to proteins in the current data ba
ses but contains an acidic N terminus characteristic of proteins invol
ved in transcription and chromatin modeling. We present evidence that
the msl-1 protein is associated with hundreds of sites along the lengt
h of the X chromosome in male, but not in female, nuclei. Our findings
support the hypothesis that msl-1 plays a direct role in increasing t
he level of X-linked gene transcription in male nuclei.