Cell differentiation without morphogenesis in Dictyostelium discoideum
Cell differentiation without morphogenesis in Dictyostelium discoideum
复制标题
盘基网柄菌无形态发生的细胞分化
作者：
C. Town;J. Gross;R. Kay
为了理解生物体中的模式形成，我们需要知道哪些因素控制着每种细胞类型的分化，哪些元素负责这些细胞类型的空间排列。在细胞黏菌盘基网柄菌中，问题相对简单，因为成熟子实体由两种基本细胞类型-柄细胞和孢子组成。成熟子实体的柄细胞来源于聚集形成的多细胞团的前细胞，而孢子则来源于后细胞1。以过低密度接种而无法聚集或允许在水下聚集的细胞通常不会分化成柄或孢子细胞。在我们的许多实验中，我们利用了这样一个事实，即以任何密度接种在琼脂上的细胞，如果被一层薄薄的玻璃纸覆盖，则不能经历超过聚集阶段的发育。在本文中，我们提出了观察细胞分化的原始报告Bonner2的茎细胞诱导环AMP在离体细胞。我们已经发现，茎细胞诱导环腺苷酸是显着依赖于细胞密度，并在这个过程中的一个低分子量的扩散因子的参与目前的证据。我们还描述了一个突变体的分离，产生孢子细胞在玻璃纸。
To understand pattern formation in an organism one needs to know what factors control the differentiation of each cell type and what elements are responsible for the spatial arrangement of these cell types. In the cellular slime mould Dictyostelium discoideum, the problem is relatively simple since the mature fruiting body consists of two basic cell types—stalk cells and spores. The stalk cells of the mature fruiting body are derived from the anterior cells of the multicellular masses formed by aggregation, whereas the spores are derived from the posterior cells1. Cells that are plated at a density too low for aggregation, or are allowed to aggregate under water do not normally differentiate into stalk or spore cells. In many of our experiments we have made use of the fact that cells plated on agar at any density fail to undergo development beyond the stage of aggregation if they are covered by a thin layer of Cellophane. In this paper we present observations on cell differentiation which derive from the original report of Bonner2 of stalk-cell induction by cyclic AMP in isolated cells. We have found that stalk-cell induction by cyclic AMP is markedly dependent on cell density, and present evidence for the involvement of a low molecular weight diffusible factor in this process. We also describe the isolation of a mutant which gives rise to spore cells under cellophane.