Progressive Tooth Pattern Changes in Cilk1-Deficient mice Depending on Hedgehog Signaling

Primary cilia function as critical sensory organelles that mediate multiple signaling pathways, including the Hedgehog (Hh) pathway, which is essential for organ patterning and morphogenesis. Disruptions in Hh signaling have been implicated in supernumerary tooth formation and molar fusion in mutant mice. Cilk1, a highly conserved serine/threonine-protein kinase localized within primary cilia, plays a critical role in ciliary transport. Loss of Cilk1 results in severe ciliopathy phenotypes, including polydactyly, edema, and cleft palate. However, the role of Cilk1 in tooth development remains unexplored. In this study, we investigated the role of Cilk1 in tooth development. Cilk1 deficiency resulted in downregulation of Hh target genes, leading to the formation of supernumerary teeth. This study reveals a previously unrecognized role of Cilk1 in controlling tooth morphology via Hh signaling.