Identification of genes expressed during hair follicle induction

The hair follicle is one of the skin appendages that develops through reciprocal epithelial-mesenchymal interactions. Although a large number of studies have been made on the mechanisms of hair follicle development, the whole molecular mechanism that governs hair follicle development remains poorly defined. To further understand the molecular basis of hair follicle development, it is necessary to identify genes that drive hair morphogenesis. As an initial approach, we attempted to identify gene products associated with mouse hair follicle development. Genes upregulated in the vibrissal hair placodes were screened by polymerase chain reaction (PCR)-based cDNA subtraction. The genes thus isolated were evaluated for their hair development-associated induction and spatiotemporal expression by quantitative reverse-transcription-PCR analysis and whole-mount in situ hybridization, respectively. Finally, we identified four genes whose upregulation and spatiotemporal expression in developing hair follicles were confirmed. Successful identification of novel hair development-associated genes will be informative as clues for further characterization of hair follicle development at the molecular level.