Zahed L, Murer-Orlando M, Bobrow M
Paediatric Research Unit, Guy's Hospital, London, UK.
Hum Genet. 1988 Oct;80(2):127-34. doi: 10.1007/BF00702854.
We have studied the cell cycle of cells obtained from chorionic villi in direct and culture preparations by incorporation of the thymidine analogue BrdU to produce late-labelling or sister chromatid differentiation patterns. We have, therefore, been able to estimate the duration of the cell cycle and, more specifically, the length of some of its phases. While results for chorionic villus sample cells in culture resembled those obtained for fibroblasts, data for the spontaneously dividing trophoblastic cells in direct preparations were different. Villi exposed to BrdU immediately after sampling showed a slight delay in the incorporation of the analogue and a lower percentage of labelled cells compared to villi treated after an overnight incubation, probably due to a temporary effect of the sampling technique. Results from semi-direct protocols suggest that cells have a G2 of no more than 4 h, and a mid-S phase of 10-16 h. The G1 period is very variable. After 48 h incubation with BrdU, only 4% of cells reach their second generation, whereas this percentage increases up to 70% after 72 h, indicating that under these experimental conditions most cells have a cell cycle of approximately 36 h. The average number of sister chromatid exchanges was similar in both direct preparations and cultures: 5.2 +/- 2.1 SCE per cell.
我们通过掺入胸腺嘧啶类似物BrdU以产生晚期标记或姐妹染色单体分化模式，研究了直接制备和培养制备的绒毛膜绒毛细胞的细胞周期。因此，我们能够估计细胞周期的持续时间，更具体地说，是其某些阶段的长度。虽然培养的绒毛膜绒毛样本细胞的结果与成纤维细胞的结果相似，但直接制备中自发分裂的滋养层细胞的数据却有所不同。与过夜孵育后处理的绒毛相比，采样后立即暴露于BrdU的绒毛在类似物掺入方面略有延迟，标记细胞的百分比也较低，这可能是由于采样技术的暂时影响。半直接方案的结果表明，细胞的G2期不超过4小时，S期中期为10 - 16小时。G1期变化很大。用BrdU孵育48小时后，只有4%的细胞进入第二代，而在72小时后这个百分比增加到70%，这表明在这些实验条件下，大多数细胞的细胞周期约为36小时。直接制备和培养中姐妹染色单体交换的平均数量相似：每个细胞5.2±2.1次SCE。
