The Retarded Hair Growth Mutation in Mice Is an Allele of Ornithine Aminotransferase

The study identified the retarded hair growth (rhg) mutation in mice as an allele of the ornithine aminotransferase (Oat) gene, caused by a G to C transversion in Exon 9, leading to a glycine to alanine substitution. This mutation resulted in elevated plasma ornithine levels, reduced OAT activity, and symptoms such as delayed hair growth, cataracts, and retinal degeneration, making it a potential model for human gyrate atrophy of the choroid and retina. The study involved a large backcross panel of 1,462 mice and 65 offspring from specific crosses, providing a robust model for understanding OAT deficiency. Arginine supplementation improved growth in mutant mice, supporting the link between the rhg mutation and OAT deficiency.