A chromosome study of 6-thioguanine-resistant mutants in T lymphocytes of Hiroshima atomic bomb survivors

• Published in: Mutation research Vol. 227; no. 1; p. 31
• Main Authors: Kodama, Y, Hakoda, M, Shimba, H, Awa, A A, Akiyama, M
• Format: Journal Article
• Language: English
• Published: Netherlands 01.09.1989
• Subjects: Aneuploidy; Cells, Cultured; Chromosome Aberrations; DNA Replication; Female; Humans; Hypoxanthine Phosphoribosyltransferase - genetics; Japan; Male; Mutation; Nuclear Warfare; T-Lymphocytes - ultrastructure; Thioguanine - pharmacology; X Chromosome - ultrastructure; Japan
• ISSN: 0027-5107; 1873-135X

Cytogenetic characterizations were made of lymphocyte colonies established from somatic mutation assays for 6-thioguanine (TG) resistance in Hiroshima atomic bomb survivors. G-banded chromosomes were analyzed in both TG-resistant (TGr) and wild-type colonies. Included were 45 TGr and 19 wild-type colonies derived from proximally exposed A-bomb survivors, as well as colonies from distally exposed control individuals who did not receive a significant amount of A-bomb radiation (18 TGr and 9-wild type colonies). Various structural and numerical chromosome abnormalities were observed in both TGr and wild-type colonies. Aberrations of the X chromosome, on which the hypoxanthine guanine phosphoribosyl transferase (HPRT) locus is present, were found in 6 colonies: 2 resistant colonies from controls (45,X/46,XX; 46,X,ins(X)), 3 resistant colonies (45,X/46,XX/46,X, + mar; 46,X,t(Xq +;14q-); 46,Y,t(Xq-;5q +)), and 1 wild-type colony (45,X/47,XXX) from proximally exposed persons. In cases with exchange aberrations, each of the break points on the X chromosome was situated proximally to band q26 where the HPRT locus is known to be assigned. DNA-replicating patterns were also studied, and it was found that abnormal X chromosomes showed early replicating patterns, while normal X chromosomes showed late replicating patterns.