[Phenotypic expression of the mutant gene diabetes insipidus in rats and criteria of genotyping by phenotype].

The autosomal semidominant mutant gene di (diabetes insipidus) is manifested in homozygotes in the form of diabetes insipidus with water consumption from 25 to 100% of body weight per day. The heterozygotes di/+ drink water at a rate higher than 5% but lower than 25%. The level of water consumption in rats with +/+ genotype does not exceed 5% of body weight per day. Segregation analysis of F1 animals yielded by various crosses showed that genotyping of di/di homozygotes is absolutely reliable at 30% and higher level of the water consumption per day.