Marin F T, Rothman F G
J Cell Biol. 1980 Dec;87(3 Pt 1):823-7. doi: 10.1083/jcb.87.3.823.
The effects of ionic environment on both the intrinsic rate of differentiation and the response to exogenous cyclic AMP in Dictyostelium discoideum have been examined. K+ specifically inhibits the rate of early development when present at concentrations > 15 mM. Na+ does not inhibit at concentrations up to 25 mM, and can partially overcome K+ inhibition. The maximum rate of development also depends upon the presence of adequate levels of extracellular Ca++. The effect of exogenous cyclic AMP on the rate of development is inhibited by the absence of Ca++, and/or the presence of high concentrations of K+. Under optimal ionic conditions, the only effect of exogenous cyclic AMP on early developments of K+. Under optimal ionic conditions, the only effect of exogenous cyclic AMP on early development is a specific inhibition. The implications of these results for current models of early developmental regulation are discussed.
已研究了离子环境对盘基网柄菌内在分化速率和对外源环磷酸腺苷(cAMP)反应的影响。当钾离子(K⁺)浓度>15 mM时,它会特异性抑制早期发育速率。钠离子(Na⁺)在浓度高达25 mM时不会产生抑制作用,并且可以部分克服钾离子的抑制作用。最大发育速率也取决于细胞外有足够水平的钙离子(Ca²⁺)。缺乏钙离子和/或存在高浓度钾离子会抑制外源环磷酸腺苷对发育速率的影响。在最佳离子条件下,外源环磷酸腺苷对早期发育的唯一影响是特异性抑制。本文讨论了这些结果对当前早期发育调控模型的意义。