Developmental signals in metazoans play critical roles in inducing cell differentiation from
multipotent progenitors. The existing paradigm posits that the signals operate directly
through their downstream transcription factors to activate expression of cell type-specific
genes, which are the hallmark of cell identity. We have investigated the mechanism through
which Wnt signaling induces osteoblast differentiation in an osteoblast-adipocyte bipotent
progenitor cell line. Unexpectedly, Wnt3a acutely suppresses the expression of a large …