title: A chromosome study of 6-thioguanine-resistant mutants in T lymphocytes of Hiroshima atomic bomb survivors.
abstract: 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.
authors: Department of Genetics, Radiation Effects Research Foundation, Hiroshima, Japan.
authors: Y
authors: Y
authors: Kodama
authors: M
authors: M
authors: Hakoda
authors: H
authors: H
authors: Shimba
authors: A A
authors: AA
authors: Awa
authors: M
authors: M
authors: Akiyama
mesh_terms: D000782:Aneuploidy; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D004261:DNA Replication; D005260:Female; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D007564:Japan; D008297:Male; D009154:Mutation; D009689:Nuclear Warfare; D013601:T-Lymphocytes / Q000648:ultrastructure*; D013866:Thioguanine / Q000494:pharmacology; D014960:X Chromosome / Q000648:ultrastructure*
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase; D013866:Thioguanine