The diverse developmental roles of each family of chromatin remodeller in mammals are summarized in Tables 1 and 2. What emerges from this distillation is the large number of phenotypes associated with mutations in these complexes. It seems that most, if not all, developmental transitions require chromatin regulation and that such regulation is more specific than was initially thought. This is consistent with the findings mentioned above that alterations to single genes can often rescue at least part of the null phenotype. In retrospect, this conclusion is perhaps not surprising given that several hundred proteins seem to be involved in a non-redundant manner in chromatin regulation during development.
