Loss of sonic hedgehog gene leads to muscle development disorder and megaesophagus in mice

Sonic hedgehog (Shh) is crucial for organogenesis in the foregut. This study investigated the function of Shh at the late-gestational stage; during which, the esophagus continues to differentiate. We established cytokeratin 14 (CK14)-Cre;Shhfl/fl mice in which the down-regulation of Shh in the epithelium occurred at approximately the same time as esophageal muscle conversion. Hematoxylin and eosin and immunohistochemical staining, with antibodies against keratin 14, Shh, patched 1 (Ptch1), Gli1, proliferating cell nuclear antigen (PCNA), α–smooth muscle actin (αSMA), high–molecular-weight caldesmon (hCD), myogenin, paired box 7 (Pax7), β3-tubulin, and protein gene product 9.5 (PGP9.5), was performed to detect specific tissue dysplasia. Organ culture was conducted in vitro, and total mRNA was extracted to determine the transcriptional dysregulation. The esophagus of CK14-Cre;Shhfl/fl mice developed into an independent tube with an obvious dilatation at postnatal d 0.5. The number of cell layers and the exp...