Defolliculated (Dfl) is a spontaneous mouse mutant with a hair-loss phenotype 
that includes altered sebaceous gland differentiation, short hair shafts, 
aberrant catagen stage of the hair cycle, and eventual loss of the hair 
follicle. Recently a similar mutant, finnegan (Fgn), with an identical phenotype 
was discovered during a phenotypic screen for mutations induced by chemical 
mutagenesis. The gene underlying the phenotype of both finnegan and 
defolliculated has been mapped to chromosome 11 and here we show that both mice 
harbor mutations in gasdermin 3 (Gsdm3), a gene of unknown function. Gsdm3(Dfl) 
is a B2 insertion near the 3' splice site of exon 7 and Gsdm3(Fgn) is a point 
mutation T278P. To investigate the role of the gasdermin gene family an 
antiserum was raised to a peptide highly homologous to all three mouse 
gasdermins and human gasdermin. Immunohistochemical analysis revealed that 
gasdermins are expressed specifically in cells at advanced stages of 
differentiation in the upper epidermis, the differentiating inner root sheath 
and hair shaft and in the most mature sebocytes of the sebaceous gland and 
preputial, meibomium, ceruminous gland, and anal glands. This expression pattern 
suggests a role for gasdermins in differentiation of the epidermis and its 
appendages.