Savage J R, Cao S
Mutat Res. 1985 Jun-Jul;150(1-2):307-12. doi: 10.1016/0027-5107(85)90127-7.
Actively cycling human lymphocytes were treated with mitomycin C for 1 h (1.4 micrograms/ml) and then grown in medium containing 10 micrograms/ml bromodeoxyuridine. Serial 5-h colcemid accumulation samples were taken up to 35 h and the air-dried methaphase spreads stained for replication banding. A complete cell-cycle subphasing analysis was made, and classified cells scored for all categories of chromatid-type aberrations and their location. In spite of the high dose which produced massive delay and cycle perturbation, there was no evidence for selective lethality of early-S cells, in fact such cells were in excess. Extreme localization of aberrations to late-replicating (mostly centromeric) regions was found at all subphases and in pre-S cells. This rules out 'localization by default' as an explanation for the observed preferential occurrence of 'break points' in these regions. The frequency of incomplete intrachanges, low in late S, rises dramatically in early S to become maximal in pre-S cells.
对处于活跃周期的人淋巴细胞用丝裂霉素C处理1小时（1.4微克/毫升），然后在含有10微克/毫升溴脱氧尿苷的培养基中培养。每隔5小时采集秋水仙酰胺积累样本，直至35小时，并对空气干燥的中期染色体铺片进行复制带染色。进行了完整的细胞周期亚期分析，并对分类后的细胞的所有染色单体型畸变类别及其位置进行了评分。尽管高剂量导致了大量延迟和周期扰动，但没有证据表明早S期细胞具有选择性致死性，事实上这类细胞数量过多。在所有亚期以及S期前细胞中，均发现畸变极度定位于晚复制（大多为着丝粒）区域。这排除了“默认定位”作为这些区域中观察到的“断裂点”优先出现的解释。不完全互换的频率在晚S期较低，在早S期急剧上升，在S期前细胞中达到最高。
