Dosage compensation and chromatin structure in Drosophila

The past year has brought significant advances in our understanding of the male-specific lethal (msl) genes and dosage compensation in Drosophila. The molecular characterization of the msl-2 gene has, to a great extent, solved the question of how msl-mediated dosage compensation is restricted to males. Molecular analyses of the msl genes have substantiated the proposal that the MSL proteins function as a multimeric complex to mediate dosage compensation. The finding that MSL-2 protein has a RING finger and the demonstration that an insulator protein facilitates the dosage compensation of X-linked genes inserted into the autosomes have opened promising avenues to identify the cis-acting dosage-compensation determinants.