Examples of spontaneous and induced X-linked traits in the mouse. (A,B) Males carrying the greasy (Gs) (A) and harlequin (Hq) (B) mutations; neither of the genes responsible has been cloned. (C) A heterozygous female carrying the broad-headed (Bhd) mutation, which is associated with a craniofacial anomaly, note the unusually short and broad snout. Comparative mapping has shown that Bhdcannot be a model for FGD1 or ATRX, but it remains an interesting skeletal mutant in which males have multiple ossification anomalies and die shortly after birth (V. Reed and Y. Boyd, in prep.). (D) A heterozygous female carrying a mutation at one of the mottled (Mo) alleles associated with death between birth and weaning of affected males (Atp7aMo-10H ). The mosaic coat can be clearly seen, in which hypopigmented areas represent populations of cells carrying the mutant allele and the normally pigmented (brown) areas represent areas of cells carrying the wild-type allele. Details of the phenotypes and references describing each of these mutants are given in Table 2.
