Robertsonian chromosome polymorphism found in a local herd of the Japanese Black cattle
Hanada, H.; Muramatsu, S.; Abe, T.; Fukushima, T.
Annales de Genetique et de Selection Animale 13(3): 205-211
The cytogenetic survey was carried out on a herd of the Japanese Black breed in the western region of Japan. The chromosome translocations of Robertsonian type were observed in 18 of 112 animals analyzed. Two kinds of translocations were identified by G-banding techniques. One translocation involved chromosomes 1 and 29 (1/29 translocation) and the other involved chromosomes 7 and 21 (7/21 translocation). Out of 18 carriers, 3 were the 1/29 translocation heterozygotes with 2n = 59, XX, t(lq 29q). Animals (14) were the 7/21 translocation carriers among which 12 were heterozygotes with 2n = 59, XY or XX, t(7q 21q) and 2 were homozygotes with 2n = 58, XX, t(7q 21q) t(7q 21q). The remaining 1 animal was a double heterozygote carrying the 1/29 and the 7/21 translocations. Based on the C-banding analysis, the translocated chromosomes 1/29 and 7/21 were monocentric and dicentric, respectively. All the carriers were phenotypically normal and appeared healthy.