X-RAY-INDUCED BREAKAGE AND REJOINING OF HUMAN INTERPHASE CHROMOSOMES
X-RAY-INDUCED BREAKAGE AND REJOINING OF HUMAN INTERPHASE CHROMOSOMES
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DOI：
10.1126/science.6648528
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发表时间：
1983-01-01
期刊：
影响因子：
56.9
通讯作者：
BEDFORD, JS
中科院分区：
文献类型：
--
作者：
CORNFORTH, MN;BEDFORD, JS
开发了一种用于高分辨率测量细胞周期G1期过早浓缩染色体断裂的方法。正常人细胞融合培养物经X射线照射后立即产生的碎片（断裂）的剂量反应在低至10.9 rad（0.109戈伊[Gray]）时呈线性，并外推至0剂量时的0效应。该曲线的斜率为0.063个断裂/细胞/rad，这比继代培养后进行有丝分裂的相同细胞中的断裂评分至少大一个数量级。当在37 ℃孵育时，C组2 h内半数断裂消失。一个较慢的，也许nonrejoining组件是明显的，在以后的孵化时间。断裂重新连接的初始速率与孵育后存活率的增加速率相似，因为修复了潜在的致命损伤，并且与最近报道的DNA双链断裂重新连接的值也非常一致。
A method was developed for the high-resolution measurement of breaks in prematurely condensed chromosomes at the G1 phase of the cell cycle. The dose response for fragments (breaks) produced immediately after X-irradiation of confluent cultures of normal human cells was linear down to 10.9 rad (0.109 Gy [Gray]) and extrapolated to 0 effect at 0 dose. The curve had a slope of 0.063 breaks/cell per rad, which is at least an order of magnitude greater than that for breaks scored in the same cells after they have progressed to mitosis following subculture. When incubated at 37.degree. C half of the breaks disappeared in 2 h. A slower, perhaps nonrejoining component was apparent at later incubation times. The initial rate of break rejoining was similar to the rate of increase in survival after incubation because of the repair of potentially lethal damage and is also in close agreement with recently reported values for the rejoining of double-strand breakage in DNA.