Forkhead transcription factor Foxf2 (LUN)-deficient mice exhibit abnormal development of secondary palate.

The forkhead genes encode a transcription factor involved in embryogenesis and pattern formation in multicellular organisms. They are mammalian transcriptional regulators that bind DNA as a monomer through their forkhead domain. The Foxf2 (LUN) mRNA is expressed in the mesenchyme directly adjacent to the ectoderm-derived epithelium in the developing tongue and in the mesenchyme adjacent to the endoderm-derived epithelium in the gastrointestinal (GI) tract, lungs, and genitalia. To investigate the developmental role of the Foxf2 gene during embryogenesis, we disrupted the Foxf2 gene and showed that these mutant mice died shortly after birth. Mice lacking the Foxf2 gene were found to develop cleft palate and an abnormal tongue. In addition, we found that the GI tract and the lungs of Foxf2-deficient newborn mice were normal in both morphology and function. These results suggest that the Foxf2 gene plays key roles in palatogenesis by reshaping the growing tongue.