Porcupine Homolog (PORCN)

PORCN has 5 transcript variants that encode 5 protein isoforms with tissue-specific variability and expression (PORCA-PROCE). To investigate how developmental expression of PORCN contributes to the specific defects in focal dermal hypoplasia (FDH), Wang et al. (2007) performed RNA in situ hybridization on embryonic day 12.5 and embryonic day 14.5 mouse embryos using a probe that detects all known mouse Porcn transcript variants. They detected Porcn and the distinctive peripheral pattern in cartilage primordia of long bones and digits, calvarian, facial skeleton, molar tooth bud, and the petrous part of the temporal bone. They also observed it in developing skin of the anterior body wall and limbs and at lower levels in developing cerebral cortex and retina.