Three steps in prespore differentiationin Dictyostelium discoideum with different requirements of cellular interaction
Three steps in prespore differentiationin Dictyostelium discoideum with different requirements of cellular interaction
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盘基网柄菌前孢子分化的三个步骤对细胞相互作用的不同要求
DOI：
10.1111/j.1432-0436.1990.tb00540.x
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发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
K. Okamoto
中科院分区：
文献类型：
--
作者：
Y. Yamada;K. Okamoto
摘要细胞外cAMP和一种分泌因子参与了盘基网柄藻的孢子前分化。在这里，我们表明，cAMP，分泌因子（S）和其他一些相互作用所需的前孢子分化，他们在完全不同的时期工作;分泌因子（S）和其他相互作用只需要在比cAMP依赖的阶段之前的阶段。根据上述结果，可将前孢子分化过程划分为三个阶段，即Ⅰ、Ⅱ和Ⅲ期。阶段I和II的过程依赖于高细胞密度。在第II阶段对高细胞密度的要求可以用条件培养基中的分泌因子代替，而在第I阶段不能。条件培养基中的因子似乎不是cAMP、氨或甲硫氨酸。与这两个阶段相反，如果提供cAMP，即使在低细胞密度下，阶段III（最后阶段）的过程也会进行，其中其他相互作用可以忽略不计。因此，已经进行到阶段II结束的细胞被认为已经获得了分化为前孢子细胞的能力，而没有除cAMP之外的进一步细胞相互作用。cAMP脉冲对于前孢子分化的任何阶段的过程都不是必需的，因为它们在咖啡因（cAMP脉冲产生的抑制剂）存在下或在缺乏cAMP中继系统的突变株（Frigid A）中进行。
Abstract Extracellular cAMP and a secreted factors have been known to be involved in prespore differentiation of Dictyostelium discoideum. Here we show that cAMP, a secreted factor(s) and some other interactions are required for prespore differentiation and that they work in completely different periods; a secreted factor(s) and other interactions are required only in the stages earlier than the cAMP-dependent stage. According to the results the process of prespore differentiation can be dissected into three sequential stages, stage I, II and III. The processes in stage I and II depend on high cell density. The requirement for high cell density in stage II could be replaced with a secreted factor(s) in conditioned medium, whereas it could not in stage I. The factor(s) in conditioned medium does not appear to be cAMP, ammonia, or methionine. In contrast to these two stages, the process in stage III, the last stage, proceeds even at low cell density if cAMP is supplied, where other interactions would be negligible. Therefore cells that have proceeded to the end of stage II are considered to have acquired a competence to differentiate to prespore cells without further cellular interactions other than cAMP. cAMP pulses are not essential for the processes of any stage of prespore differentiation, since they proceed in the presence of caffeine, an inhibitor of cAMP pulse production, or in a mutant strain (Frigid A) which is deficient in cAMP relay systems.
cAMP 脉冲对盘基网柄菌细胞表面 cAMP 受体的超诱导。
DOI：
10.1073/pnas.84.4.1030
发表时间：
1987
影响因子：
11.1
作者：
Chisholm,RL;Hopkinson,S;Lodish,HF
通讯作者：
Lodish,HF