The production of micronuclei from chromosome aberrations in irradiated cultures of human lymphocytes.

摘要: A rapid assay for chromosomal damage would greatly speed studies of the mechanism by which aberrations are formed. The characteristics such an assay--micronuclei produced in cultured human lymphocytes--are given here, together with evidence that accurately measures X-ray-induced damage. Micronuclei arise from fragments not incorporated into daughter nuclei at mitosis because they lack a centromere. In our experiments response lymphocytes different donors was very uniform and agreed well what expected metaphase analysis aberrations: (1) increase micronucleus frequency begins time first mitoses, 48 hours after cultures started, (2) exponent dose equation (y=kDn) 1.2 micronuclei. For one-hit n=1 whereas two-hit n=2. Since predominate these cultures, value n= approximately 1.8 if no mitotic delay or cell death occurred higher doses, n less than occurred, (3) micronuclei decreased factor about two when fractionated, as most two-hit. rejoining four five between 30 60 minutes, (4) cells people Down's syndrome (trisomy-21) twice control [22,23]. reflects aberration frequencies so is fast, it suitable assessment