Genetic Interplays Between Msx2 And Foxn1 Are Required For Notch1 Expression And Hair Shaft Differentiation

The 2009 study explored the roles of Msx2 and Foxn1 transcription factors in hair follicle differentiation, with a focus on Notch1 expression. It was found that both Msx2 and Foxn1 are essential for maintaining Notch1 expression in the hair matrix, which is crucial for the differentiation of the medulla and inner root sheath of hair follicles. Foxn1 may directly activate the Notch1 promoter, and both genes operate in parallel pathways that are downstream of BMP signaling. The absence of Msx2 and Foxn1 leads to a complete loss of visible external hairs, a phenotype more severe than that seen in Notch1 mutants alone. The study concludes that Msx2 and Foxn1 have overlapping but distinct roles in hair follicle development and differentiation, with Foxn1 directly regulating Notch1 expression and both being important for hair follicle regeneration. The research was conducted on genetically modified mice, and the number of subjects was not specified.