出 处:《World Journal of Gastroenterology》2003年第3期578-583,共6页世界胃肠病学杂志(英文版)
基 金:the National Natural Science Foundation of China,No.39970650
摘 要:AIM: To explore the molecular spectra and mechanism of human hypoxanthine guanine phosphoribosyl transferase (hprt) gene mutation induced by ethyluitrosourea (ENU) and 60Co γ-rays.METHODS: Independent human promyelocytic leukemia cells (HL-60) mutants at the hprt locus were isolated from untreated, ethyluitrosourea (ENU) and 60Co γ-ray-exposed cells, respectively, and verified by two-way screening. The genetic changes underlying the mutation were determined by multiplex polymerase chain reaction (PCR) amplification and electrophoresis technique.RESULTS: With dosage increased, survival rate of plated cell reduced (in the group with dosage of ENU with 100-200μg/ml, P<0.01; in the group with dosage of 60Co γ-ray with 2-4 Gy, P<0.05) and mutational frequency increased (in the group of ENU 12.5-200.0 μg/ml, P<0.05; in the group of 60Co γ-ray with 1-4 Gy, P<0.05) significantly. In the 13spontaneous mutants analyzed, 92.3 % of mutant clones did not show any change in number or size of exon, a single exon was lost in 7.7 %, and no evidence indicated total gene deletion occurred in nine hprt exons. However, deletions were found in 79.7 % of ENU-induced mutations (62.5-89.4 %,P<0.01) and in 61.7 % of gamma-ray-induced mutations (28.6-76.5 %, P<0.01). There were deletion mutations in all 9 exons of hprt gene and the most of induced mutations were chain deletion with multiplex exons (97.9 % in gammaray-induced mutants, 88.1% in ENU-induced mutants).CONCLUSION: The spectra of spontaneous mutations differs completely from that induced by EUN or 60Co γ-ray.Although both ENU and γ-ray can cause destruction of genetic structure, mechanism of mutagenesis between them may be different.AIM;To explore the molecular spectra and mechanism of human hypoxanthine guanine phosphoribosyl transferase (hprt)gene mutation induced by ethyluitrosourea(ENU)and ^(60)Co γ-rays. METHODS:Independent human promyelocytic leukemia cells(HL-60)mutants at the hprt locus were isolated from untreated,ethyluitrosourea(ENU)and ^(60)Co γ-ray-exposed cells,respectively,and verified by two-way screening.The genetic changes underlying the mutation were determined by multiplex polymerase chain reaction(PCR)amplification and electrophoresis technique. RESULTS:With dosage increased,survival rate of plated cell reduced(in the group with dosage of ENU with 100-200 μ/ml,P<0.01;in the group with dosage of ^(60)Co γ-ray with 2-4 Gy,P<0.05)and mutational frequency increased(in the group of ENU 12.5-200.0 μg/ml,P<0.05;in the group of ^(60)Co γ-ray with 1-4 Gy,P<0.05)significantly.In the 13 spontaneous mutants analyzed,92.3 % of mutant clones did not show any change in number or size of exon,a single exon was lost in 7.7 %,and no evidence indicated total gene deletion occurred in nine hprt exons.However,deletions were found in 79.7 % of ENU-induced mutations(62.5-89.4 %, P<0.01)and in 61.7 % of gamma-ray-induced mutations (28.6-76.5 %,P<0.01).There were deletion mutations in all 9 exons of hprt gene and the most of induced mutations were chain deletion with multiplex exons(97.9 % in gamma- ray-induced mutants,88.1% in ENU-induced mutants). CONCLUSION:The spectra of spontaneous mutations differs completely from that induced by EUN or ^(60)Co γ-ray. Although both ENU and γ-ray can cause destruction of genetic structure,mechanism of mutagenesis between them may be different.
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