This strain was originally used as a linkage stock for gene mapping. It is homozygous for several visible recessive mutations all located on different chromosomes including nonagouti (a), fuzzy (fz), leaden (Mlphln), and piebald (Ednrbs) and is segregating for the neurological mutation, waltzer (Cdh23v). Homozygous waltzer mice show the circling, head-tossing, deafness, and hyperactivity typical of the circling mutants. Abnormalities of the inner ear include degeneration of the organ of Corti, spiral ganglion, stria vascularis, and saccular macula. Homozygous piebald mice show irregular white spotting, the amount of which is greatly influenced by minor modifying genes. Homozygous piebald mice have dark eyes. The white areas of the coat are completely lacking in melanocytes and there is a reduction in the number of melanocytes in the choroid layer of the eye.
