Disruption of the Temporally Regulated Cloaca Endodermal β-Catenin Signaling Causes Anorectal Malformations

The study investigated the role of temporally regulated β-catenin signaling in the cloaca endoderm and its impact on anorectal malformations (ARMs) using mutant mice. Researchers found that both loss-of-function (LOF) and gain-of-function (GOF) mutations in β-catenin led to distinct ARM phenotypes, with LOF mutants showing decreased cell proliferation in the urorectal septum (URS) mesenchyme and GOF mutants exhibiting severe ARM phenotypes due to ectopic induction of growth factors such as Bmp and Fgf8. The study concluded that proper regulation of β-catenin signaling is crucial for URS development and that its dysregulation leads to abnormal growth factor activity, contributing to ARM pathogenesis.