Kano Y, Little J B
Cytogenet Cell Genet. 1986;41(1):22-9. doi: 10.1159/000132191.
A total of 130 stable, two-break reciprocal translocations were scored in G-banded karyotypes prepared from 375 metaphase spreads from a strain of human diploid fibroblasts irradiated with 400 or 600 rads and analyzed 1-20 mean population doublings later. The chromosomal location of each of the 260 breakpoints was mapped. The sites of 121 chromosomal breaks and deletions in the first postirradiation mitosis were also scored. Unlike the random distribution of these latter events, the translocation breakpoints showed not only a nonrandom distribution among chromosomes but also the existence of specific sites within chromosomes that were more frequently involved in translocations. The most notable finding was a marked excess of translocations involving the short arm of chromosome 1, in particular, band 1p22. The specific types of translocations were random, although the breakpoints were not. Eight of the 12 most frequently involved chromosomal sites were regions in which fragile sites have been mapped in human lymphocytes.
在由375个中期分裂相制备的G带核型中，对130个稳定的双断裂相互易位进行了评分，这些中期分裂相来自一株接受400或600拉德照射的人二倍体成纤维细胞，在照射后1至20个平均群体倍增时进行分析。绘制了260个断点中每个断点的染色体定位。还对照射后第一次有丝分裂中121个染色体断裂和缺失的位点进行了评分。与这些后一种事件的随机分布不同，易位断点不仅在染色体之间呈现非随机分布，而且在染色体内存在更频繁参与易位的特定位点。最显著的发现是涉及1号染色体短臂，特别是1p22带的易位明显过多。易位的具体类型是随机的，尽管断点并非如此。12个最常涉及的染色体位点中有8个是在人类淋巴细胞中已绘制出脆性位点的区域。
