BMP4-ß-gal is expressed in taste cells expressing Sox2 in circumvallate papillae. BMP4-ß-gal-IR (A, green) is expressed in fusiform cells of circumvallate taste buds, and a large number of them are Sox2-IR (B, red). In C, white arrowheads indicate double-labeled cells. In B and C, white asterisks indicate intragemmal and perigemmal cells that are Sox2-IR only, while in A and C, white arrows point to BMP4-ß-gal-IR cells that are not Sox2-IR. Scale bar: 20 μm.