Heterogeneity of Chinese hamster X chromosomes in X-ray-induced chromosomal aberrations
Heterogeneity of Chinese hamster X chromosomes in X-ray-induced chromosomal aberrations
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DOI：
10.1080/095530099140339
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发表时间：
1999-04-01
影响因子：
2.6
通讯作者：
Natarajan, AT
中科院分区：
文献类型：
--
作者：
Xiao, Y;Natarajan, AT
目的：用荧光原位杂交(FISH)技术研究X射线诱发的中国仓鼠X染色体不同长臂不同区域的染色体畸变率和分布。材料与方法：1、4GyX射线照射中国仓鼠雌性胚胎原代细胞，20h后用秋水仙素阻断法收集中期染色体。用三色荧光原位杂交技术分析了X染色体不同臂和长臂不同区域的诱发畸变率。结果：X染色体的长臂比短臂更易发生断裂。X(2)检验的结果表明，手臂之间的断裂分布不成比例，而涉及手臂的交换(双着丝粒和易位)是成比例分布的。还观察到长臂区域，即XQ1和XQ2，在断裂中的不同参与。结论：中国仓鼠染色体臂特异性探针可用于X射线诱发X染色体畸变的详细研究。中国仓鼠X染色体对X射线诱发的畸变的异质性不仅存在于短臂(常染色质)和长臂(异染色质)之间，而且还存在于X染色体长臂不同异染色质区域之间。
Purpose: To study the frequencies and distribution of X-ray-induced chromosomal aberrations in different arms as well as different regions of the long arms of Chinese hamster X chromosomes by fluorescence in situ hybridization (FISH).Material and methods: Female embryonic primary cells of Chinese hamster were exposed to 1 and 4 Gy X-rays during the G(1) stage and metaphases were collected 20 h later with colcemid-blocking. Induced aberrations involving different arms as well as different regions of the long arm of the X chromosomes were analysed by three-colour FISH using arm-specific painting probes. Distributions of aberrations in the arms were statistically analysed by chi(2)-test, with the hypothesis that aberrations are proportionally distributed on the basis of their relative lengths of the arms.Results: The long arms of the X chromosomes were frequently involved in breaks than was the short arm. The result of the chi(2)-test indicates a non-proportional distribution of breaks between the arms, while exchanges (dicentrics and translocations) involving the arms were proportionally distributed. Differential involvement of regions of the long arm, i.e. Xq1 and Xq2, in breaks was also observed. Xq21, a known common fragile site in the X chromosome, was often involved in terminal deletions.Conclusion: Arm-specific probes of Chinese hamster chromosomes are useful for the detailed study of X-ray-induced aberrations in the X chromosome. The heterogeneity of the Chinese hamster X chromosome in response to X-ray-induced aberrations exists not only between the short (euchromatin) and the long (heterochromatin) arms, but also between different heterochromatic regions of the long arm of the X chromosome.