Snail is involved in epithelial-to-mesenchymal transformation(EMT), programmed cell death(PCD), and medial epithelial seam(MES) cell migration during palatogenesis. The Snail expression becomes upregulated without inhibiting transforming growth factor(TGF)-β3 and causes cleft palate. Snail gene-encoding transcript factors, namely, Snail1, Snail2, and Snail3, can combine with the promoter of E-cadherin and inhibit its expression; these factors then induce EMT during embryogenesis and tumor metastasis. Snail is also a critical factor of MEE/MES cell survival and cell migration. MicroRNA(miRNA) are another important factor in embryogenesis. Variation in the expression pattern and mRNA binding sites of miRNA can lead to craniofacial anomalies. This review introduces the structure, functions, and expression of Snail during palatogenesis. This review also discusses the relation of Snail to EMT, PCD, and cell survival during the disappearance of MEE/MES. This review also describes the mechanisms by which miRNA regulate Snail to control the disappearance of MEE/MES.
