A New Mutant Strain of Gunn-LA Wistar Rats with Genetic Deficiencies in Bilirubin and Androsterone Uridine Diphosphate-Glucuronosyltransferases

Hooded Gunn rats which have low-activity of 4-nitrophenol uridine diphosphateglucuronosyltransferase (GT) and defect in bilirubin GT were crossed with albino LA Wistar rats with a defect in androsterone GT. From F₂ and F₃ progeny were selected Gunn-LA Wistar rats which have defective bilirubin and androsterone GTs and low-active 4-nitrophenol GT. These rats had either hooded or albino coat color. In order to establish a uniform genetic background, albino male Gunn-LA Wistar rats were crossed with heterozygous albino female Gunn-LA Wistar rats in terms of bilirubin GT. The offsprings were all albino and were classified to Gunn-LA Wistar rats and heterozygous Gunn-LA Wistar rats by assaying their hepatic GT activities or by the appearance of jaundice. The linkage relationships between GT and coat color genes are discussed.