An X chromosome balancing act

A chromosome-wide analysis of the binding of a multi-protein complex implicated in dosage compensation across the male X chromosome in Drosophila reveals that regulatory chromatin complexes need not be confined to promoter and intergenic regions, according to a trio of papers published this week in Genes & Development. Though the exact binding motifs have not been identified, the resulting map -- the highest resolution of its kind -- may shed light on how other such complexes target and bind their target sequences as well."The chromosomal wide analysis into binding sites gives insight into how histone-modifying complexes are localized to their site of action," said Barbara Panning of the University of California, San Francisco, who did not participate in the research. These studies "basically provided the starting point to begin to answer this question," Panning noted. "It's an important step. Huge would not be an understatement."Dosage compensation is the molecular...