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Regulation of Differentiation in Slime Mold Development

粘菌发育分化的调控

基本信息

批准号：
04044175
负责人：
TAKEUCHI Ikuo
金额：
$ 1.98万
依托单位：
Okazaki National Research Institutes National Institute for Basic Biology
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04044175/
关键词：
Cell differentiation Pattern formation Gene expression Cell cycle Signal transduction Cellular slime mold 転写調節形態形成運動

项目摘要

In the development of cellular slime molds, cells aggregate to form a tissue, in which two types of cells(prestalk and prespore) differentiate in the anterior and the posterior parts. To elucidate mechanisms of the pattern formation, we made the following studies.1.By the use of a vector with the actin-basal promoter provided by J.Williams, we analyzed the cis-acting regulatory regions of prespore-specific gene Dp87 and found 4 positive, prespore-specific and 1 negative, non-prespore-specific and 1 positive, cell-type-non-specific regions regulating its transcription.2.The process of stalk differentiation was found to be divided into 4 different stages. Cyclic AMP was required at the second stage and DIF at the third stage, where an unidentified low molecular weight secretory substance was also required. Cyclic AMP given at the third stage rather inhibited both of prestalk-specific ecmA and ecmB genes to the same extent, while 8-Br-cAMP which activates protein kinase A specifically ind … More uced ecmB expression, suggesting involvement of this enzyme in differential expression of the two genes.3.Relationship between the cell-cycle phase and the pattern formation was investigated by using a transformat constitutively expressingbeta-galactosidase. It was found that cells starved before a particular point (PS) within the G2 phase initiated aggregation, but sorted out to the posterior prespore region of a migrating slug, while those starved after that point lagged behind in aggregation, but sorted out to the anterior prestalk region.4.Changes in intracellular free calcium concentration ([(Ca)^<2+>]) and responsiveness to cAMP stumulation during development were studied, by using cells transformed with apoqequorin cDNA of a jellyfish. Cells exhibited a considerable increase in [(Ca)^<2+>] and acquired responsiveness to cAMP by showing a transient increase in [(Ca)^<2+>], at the time of aggregation. Prestalk cells contained twice as much [(Ca)^<2+>] and showed three times as large a response to cAMP as prespore cells. Less

在细胞黏菌的发育过程中，细胞聚集形成一个组织，其中两种类型的细胞（前柄和前孢子）在前部和后部分化。为了阐明模式形成的机制，我们进行了以下研究：1.利用J.威廉姆斯提供的肌动蛋白基底启动子载体，分析了前孢子特异基因Dp 87的顺式作用调控区，发现4个前孢子特异的和1个负的，非前孢子特异的和1个正的，2.茎分化过程分为4个不同阶段。第二阶段需要环AMP，第三阶段需要DIF，其中还需要未鉴定的低分子量分泌物质。在第三阶段给予环磷酸腺苷对前茎特异性ecmA和ecmB基因的抑制程度相当，而激活蛋白激酶A的8-Br-cAMP则特异性地抑制前茎特异性ecmA和ecmB基因的表达。 ...更多信息诱导ecmB表达，表明该酶参与了这两个基因的差异表达。3.通过使用组成型表达β-半乳糖苷酶的转化体研究了细胞周期阶段与模式形成之间的关系。发现在G2期内的特定点（PS）之前饥饿的细胞开始聚集，但被分选到迁移的蛞蝓的后前孢子区，而在该点之后饥饿的细胞在聚集方面滞后，4.研究了发育过程中细胞内游离钙浓度（[（Ca）^2+]）和对cAMP刺激反应性的变化，通过使用用水母的脱辅基发光蛋白cDNA转化的细胞。在聚集时，细胞表现出[（Ca）^<2+>]的显著增加，并通过显示[（Ca）^<2+>]的短暂增加而获得对cAMP的反应性。前柄细胞的[（Ca）^<2+>]含量是前孢子细胞的两倍，对cAMP的反应是前孢子细胞的三倍。少