Expression of the retinoblastoma family of tumor suppressors during murine embryonic orofacial development.

Objective: To elucidate the role of the retinoblastoma (Rb) family of tumor suppressors and growth regulators in transforming growth factor beta (TGFbeta)-mediated embryonic palatal growth and morphogenesis.

Design: The spatio-temporal expression patterns of the RB1, RB2/p130, and p107 tumor suppressor genes, their gene products (pRb, p130 and p107) and phosphoforms were examined in the developing murine secondary palate utilizing reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblot/immunolocalization analyses with phospho-specific antibodies.

Results: The RB1, RB2/p130, and p107 tumor suppressor genes and their gene products (pRb, p130, and p107) were differentially expressed in embryonic palatal tissue during the critical period of secondary palate development [gestational days (GD) 12-14].