Chromatin remodelling regulates gene expression during development. Exactly how is not clear but a study of vulval development in Caenorhabditis elegans provides some important new clues (see ). Andersen,Lu and Horvitz report that a nucleosome remodelling factor (NURF)-like complex promotes the expression of vulval cell fates by antagonizing the action of synthetic multivulva (synMuv) genes, which repress gene transcription through chromatin remodelling. Simultaneous loss-of-function mutations in two synMuv genes - these include genes that encode chromatin-remodelling proteins and homologues of well-known transcription repressors such as Rb - produce worms with ectopic vulvae, indicating that synMuv proteins normally suppress vulval cell fates. The researchers show that ISW-1 (an orthologue of the Drosophila ATP-dependent chromatin remodelling enzyme ISWI) probably acts with NURF-1 (an orthologue of Drosophila NURF301) to promote the synMuv phenotype during vulval development. These results suggest that cell fate might be precisely regulated during development through the antagonistic chromatin-remodelling activities of transcriptional repressor complexes and NURF-like complexes.
