Savage J R, Reddy K S
Mutat Res. 1987 May;178(1):65-71. doi: 10.1016/0027-5107(87)90087-x.
This paper summarizes the results of a series of experiments with primary cultures of normal human fibroblasts and lymphocytes designed to investigate chromatid aberration 'break-point' localization after a 1-h pulse of mitomycin C. For discontinuities and interchanges, 60-70% of the inferred 'break-points' were localized to defined paracentric heterochromatin and the centromeric regions (i.e. approximately 21% by length of the normal karyotype), irrespective of 'dose', aberration frequency, sample time or cycle sub-phase as determined by replication banding. Chromatid intrachanges are non-(or negatively) localized because of an inescapable scoring bias. SCE in fibroblasts show no such localization. Cells from a number of Fanconi's anaemia subjects were examined. In poorly growing cultures, localization was as high as in normal cells but in vigorous cultures localization was reduced to approximately 30%. It is suggested that the enhanced aberration sensitivity of this syndrome could arise because non-localized aberrations, usually eliminated before division in normal cells, are allowed to reach mitosis in FA cells.
本文总结了一系列针对正常人成纤维细胞和淋巴细胞原代培养物的实验结果，这些实验旨在研究丝裂霉素C 1小时脉冲处理后的染色单体畸变“断点”定位。对于不连续和互换情况，无论“剂量”、畸变频率、采样时间或通过复制带型确定的细胞周期亚期如何，60 - 70%的推断“断点”定位于特定的近着丝粒异染色质和着丝粒区域（即约占正常核型长度的21%）。由于不可避免的计分偏差，染色体内互换无（或负）定位。成纤维细胞中的姐妹染色单体交换无此类定位。对一些范科尼贫血患者的细胞进行了检查。在生长缓慢的培养物中，定位与正常细胞一样高，但在生长旺盛的培养物中，定位降至约30%。有人提出，该综合征增强的畸变敏感性可能是因为通常在正常细胞分裂前被消除的非定位畸变在范科尼贫血细胞中能够进入有丝分裂。
