Two cases of BrdU-requiring fragile site, fra (10) (q25), found in a Japanese population are described. The incidence in the present study is lower than that in the Australian Caucasian population, being 0.84% and 2.5% respectively. The difference of incidence might be due to the difference between ethnic groups.
A male of the BUF/Ms strain rat with 3;8 translocation is obtained after γ-irradiation. The large broken end of the no. 8 chromosome was translocated tandemly to the no. 3 chromosome. By several coatings between the translocation male and female it is shown that the male and the female with the translocation is fertile and the translocation homozygous female was also fertile.
In the 11-Y translocation heterozygous male of the NIG-III strain rat, whether or not, the nucleolar organizer region (NOR) is translocated to the dot-Y is confirmed by the observation of the Ag-NOR staining technique. As the NOR is clearly demonstrated in the dot-Y, it is obviously proved that the 11-Y translocation is the reciprocal event between the autosome and the Y-chromosome.
Stable type chromosomal rearrangements in the irradiated bone marrow cells are analyzed in 13 males of the SD rats and 20 males of the C3H/He mice. The rat chromosomes nos. 4, 5, 8, 10, and 13, and the mouse chromosomes nos. 2, 6, 9, 11, 12, 13, and 14, among which 3 pairs are homeologous in both species are frequently involved in the rearrangements. The homologous genetic control for these rearranged chromosomes is suggested.
A polymorphism of α-L-fucosidase has been found in human urine by isoelectric focusing technique. Three phenotypes αFUC 1, αFUC 2-1, and αFUC 2 were determined by two common alleles, αFUC1 and FUC2. Paired leucocyte and urine samples from the same individuals were analyzed, and it was found that the phenotypes of the pairs were identical. Estimated frequencies of αFUC1 and αFUC2 among Japanese were 0.766 and 0.234, respectively.