Watson G E, Pocock D A, Papworth D, Lorimore S A, Wright E G
Radiation and Genome Stability Unit, Medical Research Council, Harwell, UK.
Int J Radiat Biol. 2001 Apr;77(4):409-17. doi: 10.1080/09553000010028476.
To study stable and unstable chromosomal aberrations in the haemopoietic cells of CBA/H mice after exposure to both high- and low-LET radiations.
Chromosomal aberrations were scored in the clonal progeny of X-, alpha- or non-irradiated short-term repopulating stem cells using the spleen colony-forming unit (CFU-S) assay, 12 days post-transplantation and in the bone marrow reconstituted by X-, neutron- or non-irradiated exogenous (transplanted) or endogenous (X- or neutron whole-body-irradiated) long-term repopulating stem cells for up to 24 months.
Chromosomal instability was demonstrated in 3-6% of cells in all cases. After transplantation of X- or neutron-irradiated bone marrow approximately 8% of cells with stable aberrations were recorded at all times. After 3Gy X- or 0.5 Gy neutron- whole-body irradiation stable aberrations were detected in approximately 17 and 5% of cells respectively.
Chromosomal instability induced in vitro can be transmitted in vivo by transplantation of haemopoietic stem cells exposed to high- or low-LET radiations. Comparable instability can be induced and shown to persist for the remaining lifetime after whole-body irradiation. There was no direct relationship between the expression of stable and unstable aberrations and significant interanimal variation in the expression of both stable and unstable aberrations.
研究CBA/H小鼠造血细胞在受到高传能线密度和低传能线密度辐射后出现的稳定和不稳定染色体畸变。
在移植后12天,使用脾集落形成单位(CFU-S)试验,对X射线、α射线照射或未照射的短期再增殖干细胞的克隆后代中的染色体畸变进行评分;对于由X射线、中子照射或未照射的外源性(移植的)或内源性(全身X射线或中子照射)长期再增殖干细胞重建的骨髓,进行长达24个月的染色体畸变评分。
在所有情况下,均有3% - 6%的细胞表现出染色体不稳定。移植X射线或中子照射的骨髓后,任何时候都有大约8%的细胞出现稳定畸变。全身接受3Gy X射线或0.5Gy中子照射后,分别在大约17%和5%的细胞中检测到稳定畸变。
体外诱导的染色体不稳定可通过移植受高传能线密度或低传能线密度辐射的造血干细胞在体内传递。全身照射后可诱导出类似的不稳定性,并显示在剩余寿命期内持续存在。稳定和不稳定畸变的表达之间没有直接关系,且稳定和不稳定畸变的表达在动物个体间存在显著差异。