Recinoic Acid (RA) is know to induce cleft palate in all mammalian species tested. The etiology of RA-induced cleft palate has been extensively investigated in C57B16 mouse embryos. Recently shown was distinct site- and stage-specific expression pattern of the RNAs encoding the three TGFbeta isoforms (TGFbeta1, TGFbeta2 and TGFbeta3) during normal murine palatogenesis suggesting an important role for these regulators of cell function in this developmental process. TGFbeta1 and TGFbeta3 are expressed in the medial edge epithelium at the time of palatal fusion, whereas TGFbeta2 RNA is exclusively mesenchymal. The present study investigated the expression of TGFbetas in mouse embryo palates from mothers treated in vivo with 100mg/Kg all-trans RA on day 10 post coitum (p.c.) and collected on day 12 and day 14 p.c. The RA-treated embryos showed marked hypoplasia of the palatal shelves but, surprisingly, did not show any major alteration in the RNA localization of TGFbeta1 or TGFbeta3. There were, however, minor changes in the expression characteristics of TGFbeta2 RNA.