The structure-function link of compensated chromatin in Drosophila.

All the aspects of transcription are controlled by complexes that modify or remodel chromatin at the level of individual genes, gene clusters, or whole chromosomes. The MSL complex that is responsible for dosage compensation in Drosophila is an example of complexes that operate at the whole-chromosome level on the transcription of individual genes. Recent experiments using traditional genetic analysis, molecular cytology, chromatin immunoprecipitation, or microarray technology have characterized the function of the two known enzymatic components of the MSL core complex and have identified the sequence characteristics that allow spreading of the complex along the X chromosome and a specific histone modification of active X-linked genes to which it is attracted. Further progress in understanding the function of this complex will benefit from biophysical approaches.