Differences between tabby and downless mouse epidermis and dermis in culture

The semi-dominant X-linked gene tabby (Ta) in the mouse, and one of its recessive autosomal mimics, downless (dl) each produces a mutant syndrome that includes absence of hairs on the tail due to failure of tail hair follicle initiation. However, whereas downless tails failed to produce hair follicles in culture on the chick chorioallantoic membrane, which is in keeping with the adult phenotype of both downless and tabby mice, tabby tails produced follicles at about 40% of the control level. Furthermore, in contrast to previous findings for downless, the culture of mixed genotype epidermis-dermis combinations provided no evidence of a primary epidermal effect in tabby.