One female specimen of the Chinese raccoon dog, Nyctereutesprocyonoides, collected in Yunnan has 57 chromosomes. Based on the comparative analysis of the karyotype with those of the Finnish and Japanese specimens, it is shown that the karyotype of the Chinese specimen is consisted of 52A+XX+ 3 B's. This karyotype is similar to the Finnish specimens with 2n=52A+XY+ B's. An evolutional relation between the Japanese and Chinese raccoon dogs is discussed.
By using the high resolution R-banding technique, the clear multiple bands in the amphibian chromosomes are successfully obtained. This R-band is one form of the Brdu-replicating bands, which is useful to identify all chromosomes and compare the chromosomes of different species of Amphibia. The karyotypes of two Rana species, R. nigromaculata and R. japonica japonica are shown by the present technique.
The karyotypes of three black rats collected in Kota Kinabalu, Sabah, Borneo, and one specimen collected in New Caledonia are analysed. The former three black rats are the Asian type having 42 chromosomes. Among them no. 1 chromosomes are characterized by having all subtelocentric pair, but pair nos. 9 and 13 are polymorphic with regard to the acrocentric and subtelocentric chromosomes. One specimen from New Caledonia is characterized by a typical Oceanian type idiogram with 38 chromosomes.
The karyotypes of 5 specimens of the Norway rats, Rattusnorvegicus, collected in Miyake island, Tokyo, are investigated. Chromosome pair nos. 3, 11 and 12 are polymorphic due to the acrocentric and the subtelocentric types. One specimen among them is characterized by having 43 chromosomes, among which one acrocentric is a supernumerary or B-element.
R-29(r, ---) heterozygous erythrocytes were titrated against Rh blood grouping antisera in comparison with ordinary cells. Gene dosage effect was suggested to work on Rh 2-5 (rh', C; rh", E; hr', c; hr", e) antigens but not on Rh 1 (Rho, D) antigen.