Hereditary multiple malformation in Japanese quail: a possible powerful animal model for morphogenetic studies.

Hereditary multiple malformation (HMM), a new mutation of Japanese quail (Coturnix japonica), is controlled by an autosomal recessive gene. The proposed gene symbol for the mutant gene is hmm. The majority of the homozygotes die at the sixth day of incubation, and the remainder die at various stages by 15 days of incubation. The homozygotes surviving to the late embryonic stage have greatly shortened lower and upper beaks that are set apart and show an early embryo-like body shape, with feather buds but no plumules. Furthermore, they show syndactylous polydactyly in both fore and hind limbs. In the abdomen of the homozygote, a part of the ventriculus, liver, and small intestine protrudes out of the umbilicus region. In the skeleton of the late HMM embryos, ossification is generally delayed and morphogenetic abnormalities are observed all over the body. This mutant seems to become a powerful animal model in the research fields for morphogenesis.