The Transcriptional Repressor CDP (Cutl1) Is Essential for Epithelial Cell Differentiation of the Lung and the Hair Follicle

The study investigated the role of the Cutl1 gene, which codes for the transcriptional repressor CDP, by creating a Cutl1(lacZ) null mutation in mice. The mutant mice exhibited retarded lung epithelial differentiation, leading to death shortly after birth on inbred backgrounds, while outbred mice survived but showed growth retardation and abnormal hair due to disrupted hair follicle morphogenesis. The inner root sheath (IRS) was reduced, and the transcription of Sonic hedgehog and IRS-specific genes was deregulated, highlighting CDP's essential role in lung maturation and hair follicle cell-lineage specification.