Harlequin colour in the Great Dane dog

Abstract

Breeding data from Eire and Great Britain confirm the hypothesis of Sponenberg (1985) that the harlequin colour of the Great Dane breed of dog is due the combined action of a dominant gene H with the merle gene M in the genotype H+M+. The typical bluish coloration induced by M is modified to white by the action of H. The H gene is a prenatal lethal when homozygous HH and this study offers clear indication that the heterozygous H+ interacts with M to reduce the viability of white merle homozygotes H+MM.