The Two Functional Keratin 6 Genes of Mouse Are Differentially Regulated and Evolved Independently from Their Human Orthologs

The study reported on the cloning and characterization of two functional keratin 6 (K6) genes in mice, mK6alpha and mK6beta, which were found to be organized in tandem and differentially regulated at the mRNA level in various stratified epithelia. The research suggested that these mouse K6 genes evolved independently from their human counterparts after species divergence. The mK6alpha isoform was predominantly expressed in the outer root sheath of hair follicles in intact trunk skin of adult mice. Both mK6alpha and mK6beta mRNAs were rapidly induced in the epidermis and proximal hair follicles following acute injury or phorbol ester application, although they exhibited different induction kinetics. These findings provided insights into the evolution, regulation, and function of K6 genes in mammals.