Primmett D R, Norris W E, Carlson G J, Keynes R J, Stern C D
Department of Human Anatomy, Oxford, UK.
Development. 1989 Jan;105(1):119-30. doi: 10.1242/dev.105.1.119.
This study provides evidence that cells destined to segment together into somites have a degree of cell division synchrony. We have measured the duration of the cell division cycle in somite and segmental plate cells of the chick embryo as 9.5 h using [3H]thymidine pulse- and-chase. Treatment of embryos with any of a variety of inhibitors known to affect the cell division cycle causes discrete periodic segmental anomalies: these anomalies appear about 6-7 somites after treatment and, in some cases, a second anomaly is observed 6 to 7 somites after the first. Since somites take 1.5 h to form, the 6- to 7- somite interval corresponds to about 9-10 h, which is the duration of the cell cycle as determined in these experiments. The anomalies are similar to those seen after heat shock of 2-day chick embryos. Heat shock and some of the other treatments induce the expression of heat-shock proteins (hsp); however, since neither the expression nor the distribution of these proteins relate to the presence or distribution of anomalies seen, we conclude that hsps are not responsible for the pattern of segmental anomalies observed. The production of periodic segmental anomalies appears to be linked to the cell cycle. A simple model is proposed, in which we suggest that the cell division cycle is involved directly in gating cells that will segment together.
本研究提供了证据，表明注定要一起分割形成体节的细胞具有一定程度的细胞分裂同步性。我们使用[3H]胸腺嘧啶核苷脉冲追踪法，测得鸡胚体节和体节板细胞的细胞分裂周期时长为9.5小时。用已知会影响细胞分裂周期的多种抑制剂中的任何一种处理胚胎，都会导致离散的周期性节段异常：这些异常在处理后约6 - 7个体节处出现，并且在某些情况下，在第一个异常出现后6至7个体节处会观察到第二个异常。由于体节形成需要1.5小时，6至7个体节的间隔约对应9至10小时，这与这些实验中确定的细胞周期时长一致。这些异常与2日龄鸡胚热休克后出现的异常相似。热休克和其他一些处理会诱导热休克蛋白（hsp）的表达；然而，由于这些蛋白质的表达和分布均与所观察到的异常的存在或分布无关，我们得出结论，热休克蛋白并非所观察到的节段异常模式的原因。周期性节段异常的产生似乎与细胞周期有关。我们提出了一个简单的模型，其中我们认为细胞分裂周期直接参与对将一起分割的细胞进行调控。
