Crinkled (Cr) is an autosomal recessive mouse mutation that was induced by nitrogen mustard in 1949 by Auerbach and Falconer. The phenotype resembles Tabby (Ta) and Downless (Dl) with affected teeth, hair and some glands. The incisors can be absent or reduced in size and the molars are smaller than normal with the third molar often absent (Gruneberg, 1965, 1966). The hair is finer than wildtype with only one of the four hair follicle types normally present (Falconer et al, 1951). Glands affected include at least the sweat glands (Rao et al, 1994) and the Meibomian glands (Falconer et al, 1951). It has been reported that the copper and superoxide dismutase concentrations in the embryonic and young adult livers of cr mice are reduced (Keen and Hurley, 1979) and that treatment with copper during the embryonic period can reverse the hair phenotype to nearly wildtype (Hurley and Bell, 1975). However, later studies have questioned these results (Prohaska, 1986).
It has been suggested that Crinkled may be a homologue of one of the human autosomal ectodermal dysplasias (Munoz et al, 1997). The mutation has been mapped to mouse chromosome 13. The gene has not been cloned but as Tabby and downless code for TNF family members it is very likely that Crinkled is also involved in the TNF signalling pathway.