Li N, Zhou X T
Hum Genet. 1985;71(4):363-5. doi: 10.1007/BF00388465.
Peripheral lymphocytes from 16 healthy adults, 9 pregnant women, and 3 fragile X syndrome patients were cultured in Eagle's minimum essential medium without folic acid (MEM-FA). The addition of 2 mM, 4 mM, or 8 mM uridine 24 h or 72 h prior to harvest resulted in increases of chromosome gaps or breaks, especially at hot points 3p14, 16q23-24, and at fragile site Xq27. Pregnant women showed higher frequencies of 3p14 breaks and total chromosome breaks than men and non-pregnant women. The other chromosome regions, such as 6q26, 7q23, 7q35, 6p25, Xp22, 14q23 and 11p13, also frequently showed gaps or breaks. The results indicated that the unbalance of nucleotide pools was one of the causes of chromosome breakages. The higher frequencies of chromosome gaps and breaks under the condition of thymidylate stress may be due to the misincorporation of uracil instead of thymine into DNA.
从16名健康成年人、9名孕妇和3名脆性X综合征患者身上获取外周淋巴细胞，在不含叶酸的伊格尔最低限度基本培养基（MEM - FA）中培养。在收获前24小时或72小时添加2 mM、4 mM或8 mM尿苷会导致染色体间隙或断裂增加，尤其是在热点区域3p14、16q23 - 24以及脆性位点Xq27处。孕妇3p14断裂和总染色体断裂的频率高于男性和非孕妇女性。其他染色体区域，如6q26、7q23、7q35、6p25、Xp22、14q23和11p13，也经常出现间隙或断裂。结果表明核苷酸池失衡是染色体断裂的原因之一。在胸苷酸应激条件下染色体间隙和断裂频率较高可能是由于尿嘧啶而非胸腺嘧啶错误掺入DNA所致。
