Genetic Aspects of Polymorphic C-bands in the Chromosomes of the Black Rat (Rattus rattus tanezumi) in Japan

抄録

Some genetic aspects are presented on C-band polymorphism in 62 Japanese black rats (R. rattus tanezumi) of a breeding colony origin. Among 20 autosome pairs, nos. 1, 3, 7, 8, 10, 11 and 13 are polymorphic regarding the presence or absence of C-bands. Pairs no. 2, 4, 5 and 6 are devoid of C-bands, while pairs no. 9 and 12, and other small metacentric pairs (nos. 14 to 20) carry C-bands. In pair no. 1 showing acrocentric and subtelocentric polymorphism, merely the acrocentric member shows C-band. Such correlation between the banding pattern and the chromosome type is not found in pairs no. 9 and 13, though there occurs acrocentric and subtelocentric polymorphism in them. Results of genetic analysis of C-band polymorphism carried out in 24 offspring from 5 litters coming from different parents indicate that the C-band characteristics of the black rats show a regular segregation in offspring with the Mendelian ratio.