Cloning and characterization of the murine Imitation Switch (ISWI) genes:: differential expression patterns suggest distinct developmental roles for Snf2h and Snf21

Here we report the cloning of two cDNAs, Snf2h and Snf2l, encoding the murine members of the imitation Switch (ISWI) family of chromatin remodeling proteins. To gain insight into their function we examined the spatial and temporal expression patterns of Snf2h and Snf2l during development. In the brain, Snf2h is prevalent in proliferating cell populations whereas. Snf2l is predominantly expressed in terminally differentiated neurons after birth and in adult animals, concomitant with the expression of a neural specific isoform. Moreover, a similar proliferation/differentiation relationship of expression for these two genes was observed in the ovaries and testes of adult mice. These results are consistent with a role of Snf2h complexes in replication-associated nucleosome assembly and suggest that Snf2l complexes have distinct functions associated with cell maturation or differentiation.