Novel myosin heavy chain encoded by murine dilute coat colour locus

HUNDREDS of murine dilute mutations have been identified and analysed, making dilute one of the best genetically characterized of all mammalian loci. The recessive dilute (d) coat colour muta-tion carried by many inbred strains of mice produces a lightening of coat colour, caused by an abnormal adendritic melanocyte morphology that results in an uneven release of pigment granules into the developing hair shaft^1,2. Most dilute alleles (dilute-lethal) also produce a neurological defect, characterized by convulsions and opisthotonus, apparent at 8-10 days of age and continuing.