Lucas J N, Cervantes E
University of California, P.O. Box 2573 Dublin, CA 94568, USA.
Int J Radiat Biol. 2002 Jun;78(6):449-55. doi: 10.1080/09553000110097190.
To investigate large-scale relative movement (position change) of interphase chromosome territories (ICT), as indicated by the separation of chromosome derivatives following exposure to ionizing radiation.
A simple experiment was conducted to investigate large-scale movement of ICT, using whole chromosome 18 painting to measure the frequency of fluorescent ICT in irradiated lymphocytes, cultured over 9 days (seven cell cycles). After chromosome 18 painting, derivative chromosome territory separation was indicated by the observation of three fluorescent ICT in aberrant cells compared with the presence of two fluorescent ICT in normal cells. The frequencies of interphase nuclei containing three fluorescent chromosome territories for unirradiated resting lymphocytes and for lymphocytes acutely irradiated with 2.25 or 5.5 Gy 137Cs gamma-rays were measured for each culture time point of 0, 1, 2, 3, 4, 7 and 9 days.
No significant difference was observed in the frequency of three ICT between the average of the controls and irradiated cells cultured for 0, 1 and 2 days. However, irradiated cells cultured for >or=3 days showed a significant increase in the frequency of three fluorescent ICT over those cultured for <or=2 days, as well as over all controls. The frequency of cells containing three territories for cultures that received a dose of 5.5 Gy was about twice that for cultures that received a dose of 2.25 Gy for 3-, 4-, 7- and 9-day cultures.
The finding that significant large-scale movement was not observed within the first 48 h of cell culture, but was seen in cultures after 48 h, suggests that ICT do not undergo large-scale movement relative to each other until lymphocytes go through mitosis.
通过观察电离辐射后染色体衍生物的分离情况，研究间期染色体领地（ICT）的大规模相对运动（位置变化）。
进行了一项简单实验来研究ICT的大规模运动，使用全染色体18探针来测量照射后淋巴细胞中荧光ICT的频率，细胞培养9天（七个细胞周期）。在进行染色体18探针标记后，通过观察异常细胞中三个荧光ICT，与正常细胞中两个荧光ICT的情况相比，来指示衍生染色体领地的分离。在0、1、2、3、4、7和9天的每个培养时间点，测量未照射的静止淋巴细胞以及急性照射2.25或5.5 Gy 137Csγ射线的淋巴细胞中含有三个荧光染色体领地的间期核频率。
在0、1和2天培养的对照细胞和照射细胞的平均值之间，未观察到三个ICT频率的显著差异。然而，培养≥3天的照射细胞与培养≤2天的细胞以及所有对照相比，三个荧光ICT的频率显著增加。对于接受5.5 Gy剂量的培养物，在3、4、7和9天培养时，含有三个领地的细胞频率约为接受2.25 Gy剂量培养物的两倍。
细胞培养的前48小时内未观察到显著的大规模运动，但在48小时后的培养中观察到，这一发现表明，直到淋巴细胞经历有丝分裂，ICT之间才会发生大规模相对运动。
