Developmentally regulated cell surface alterations in Dictyostelium discoideum
Developmentally regulated cell surface alterations in Dictyostelium discoideum
复制标题
盘基网柄菌发育调控的细胞表面变化
作者：
J. Smart;R. Hynes
细胞黏菌盘基钢霉的生命周期可以分为两个相互排斥的阶段。在植物状态下，细胞每隔几小时进行一次裂变，其特征是细胞内缺乏通讯；而发育的社会状态，是由营养物质的耗尽所引发的，表现出多种形式的这种相互作用。这些包括对趋化信号作出反应和传递的能力，以及形成稳定的物种特异性细胞间接触的能力。形成稳定细胞接触的能力可以在没有趋化梯度的情况下发展，正如在无营养盐溶液中悬浮8-9小时的细胞电镀后立即形成正常聚集体所证明的那样（参考文献1）。在发育过程中，新的抗原出现并在细胞表面起作用3,4。Gerisch和他的同事已经证明，针对12h细胞聚集体表面的单价抗体特异性地干扰了细胞间稳定接触的形成4 - 6。此外，已经证明，在12 h聚集体的膜制备中存在一种发育控制的热稳定成分，它会特异性地干扰生物体的形态和生化发育（j.e.s.和J. Tuchman，未发表，以及J. Tuchman等人，未发表）。
THE life cycle of the cellular slime mould, Dictyostelium discoideum, can be divided into two mutually exclusive phases1. The vegetative state, in which the cells divide by fission every few hours, is characterised by the absence of intracellular communication; whereas the developmental social state, which is initiated by the exhaustion of nutrients, exhibits many forms of such interactions. These include the ability to respond to and relay chemotactic signals2, and to form stable species-specific cell to cell contacts3–5. The ability to form stable cell contacts can develop in the absence of a chemotactic gradient, as demonstrated by the immediate formation of normal aggregates upon plating of cells which have been maintained in suspension in a nutrient-free salt solution for 8–9 h (ref. 1). New antigens appear and function on the cell surface during development3,4. Gerisch and his coworkers have shown that univalent antibodies directed against the surface of 12 h cell aggregates interfere specifically with the formation of the stable cell to cell contacts4–6. Furthermore, it has been demonstrated that a developmentally controlled, heat-stable component, which is present in membrane preparations from 12 h aggregates, interferes specifically with the morphological and biochemical development of the organism (J.E.S., and J. Tuchman, unpublished, and J. Tuchman et al., unpublished).