A NEW CLASS OF RAPIDLY DEVELOPING MUTANTS IN DICTYOSTELIUM-DISCOIDEUM - IMPLICATIONS FOR CYCLIC-AMP METABOLISM AND CELL-DIFFERENTIATION
A NEW CLASS OF RAPIDLY DEVELOPING MUTANTS IN DICTYOSTELIUM-DISCOIDEUM - IMPLICATIONS FOR CYCLIC-AMP METABOLISM AND CELL-DIFFERENTIATION
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DOI：
10.1016/0012-1606(83)90018-0
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发表时间：
1983-01-01
影响因子：
2.7
通讯作者：
YANAGISAWA, K
中科院分区：
文献类型：
--
作者：
ABE, K;YANAGISAWA, K
很快，人们对盘状 D. discoideum 的发育 (rde) 突变体进行了遗传和生化研究，其中细胞提前分化为茎和孢子细胞，但没有正常的形态发生。遗传互补测试表明，分离的 16 个 rde 突变体至少可分为 2 组（A 组和 C 组），第一个描述的 rde 突变体 FR17（Sonneborn 等人，1963）属于 A 组。形态学研究揭示了 A 组和 C 组突变体在发育和最终形态方面的一些差异。在A组突变体中，细胞从营养细胞分化为聚集感受态细胞所需的时间减少，而在C组突变体中，聚集完成后孢子和茎细胞分化所需的时间缩短。显然，C 组突变体代表了一类新的 rde 突变体，并且至少存在 2 种机制参与调节盘状 D. discoideum 的发育时间。细胞相关和细胞外磷酸二酯酶活性以及细胞内和总 cAMP 水平的测量表明，两组的 cAMP 代谢在发育过程中均发生显着改变。 A组突变体在整个发育过程中表现出早熟和过量的磷酸二酯酶和cAMP产生； C组突变体的细胞内cAMP水平极低，并且孢子和茎细胞分化发生时这些水平没有明显增加。虽然在所有研究的 rde 突变体中 cAMP 代谢均异常，但存在几种不同类型的紊乱，不一定涉及 cAMP 的过量产生。
Rapidly, developing (rde) mutants of D. discoideum, in which cells precociously differentiated into stalk and spore cells without normal morphogenesis, were investigated genetically and biochemically. Genetic complementation tests demonstrated that the 16 rde mutants isolated could be classified into at least 2 groups ( groups A and C) and that the 1st described rde mutant FR17 (Sonneborn et.al. 1963) belongs to group A. Morphological studies revealed several differences in development and final morphology between group A and group C mutants. In group A mutants, the time required for cell differentiation from vegetative cells to aggregation competent cells is reduced, whereas the time required for spore and stalk cell differentiation following the completion of aggregation is shortened in group C mutants. Apparently, group C mutants represent a new class of rde mutants and that there exist at least 2 mechanisms involved in regulating the timing of development in D. discoideum. Measurements of cell-associated and extracellular phosphodiesterase activities and intracellular and total cAMP levels revealed that cAMP metabolism in both groups is significantly altered during development. Group A mutants showed precocious and excessive production of phosphodiesterase and cAMP during the entire course of development; intracellular cAMP levels in group C mutants were extremely low and spore and stalk cell differentiation occurred without an apparent increase in these levels. While cAMP metabolism is abnormal in all the rde mutants studied, there exist several distinct types of derangement, not necessarily involving the overproduction of cAMP.