The peri-implantation lethal phenotype of mice lacking Brg1, BAF155 or BAF47 indicates that esBAF has an essential role in early embryonic development (Bultman et al., 2000; Kim et al., 2001; Klochendler-Yeivin et al., 2000). Cre-mediated deletion of Brg1 impairs self-renewal of cultured ES cells but not mouse embryonic fibroblasts (MEFs) (Ho et al., 2009b) or glial cells (Lessard et al., 2007). Brg1-deleted ES cells first lose proliferative capacity and, after several passages, lose the expression of ES cell markers Oct4, Sox2 and Nanog; they are also defective in forming ectodermal and mesodermal lineages during spontaneous differentiation, indicating a loss of pluripotency.
