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Regulation of gene expression during cell differentiation in the cellular slime molds

细胞粘菌细胞分化过程中基因表达的调控

基本信息

批准号：
01044080
负责人：
TAKEUCHI Ikuo
金额：
$ 4.1万
依托单位：
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：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01044080/
关键词：
Cellular slime mold Cell differentiation Pattern formation Cell sorting Gene expression

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 the mechanisms of cell differentiation and pattem formation, we made the following studies.(1) We have shown that cells cultured in liquid in a roller tube form an agglutinate in which prestalk, and prespore cells exhibit a definite pattern of differentiation without undergoing morphogenesis. Williams made a similar culture of cells whose expression of prestalk-specific ecmA and ecmB genes can be histochemically detected by BATA-galactosidase activity. In the agglutinates forined, cells expressing ecmA first arose randomly and then were collected to the center, while those expressing ecmB appeared on the surface layers. The result is consistent with the previous one obtained with the pattem of prespore differentiation and indicates that the differentiation pattem is tonned by sorting out of differentiated cells.(2) We have previously shown that the upstream region between -442 and -349 bp of presporespecific Dp87 gene is important for its expression. When this region is fused with the basal promoter of slime mold actin gene, the chimera gene was expressed from the vegetative stage and no difference in expression was detected between prestalk and prespore cells. This suggests that the upstream region only enhances the amount of transcription, but that cell-type-and development-specific expression is regulated by the region below -349 bp.(3) Expression of Dp87 gene during normal development was examined by using cells transformed with the promoter of Dp87 fused with BATA-galactosidase gene. Cells expressing Dp87 first appeared randomly in the aggregation streams and were later accumulated in the basal part of the aggregation centers, continuing the above notion that the differentiation pattem is formed by sorting out of differentiated cells.

在细胞粘菌的发育过程中，细胞聚集形成组织，其中两种类型的细胞（前柄和前孢子）在前部和后部分化。为了阐明细胞分化和模式形成的机制，我们进行了以下研究。（1）我们已经证明，在滚管中液体培养的细胞形成凝集物，其中前柄和前孢子细胞表现出明确的分化模式，而不经历形态发生。 Williams 制作了类似的细胞培养物，其前柄特异性 ecmA 和 ecmB 基因的表达可以通过 BATA 半乳糖苷酶活性进行组织化学检测。在凝集物中，表达ecmA的细胞首先随机出现，然后收集到中心，而表达ecmB的细胞出现在表层。该结果与之前获得的前孢子分化模式一致，表明分化模式是通过分选分化细胞来调整的。(2)我们之前已经表明，前孢子特异性Dp87基因的上游-442和-349 bp之间的区域对其表达很重要。当该区域与粘菌肌动蛋白基因的基础启动子融合时，嵌合体基因从营养阶段开始表达，并且在前柄和前孢子细胞之间没有检测到表达差异。这表明上游区域仅增强转录量，但细胞类型和发育特异性表达受-349 bp以下的区域调节。(3)使用与BATA-半乳糖苷酶基因融合的Dp87启动子转化的细胞检查正常发育期间Dp87基因的表达。表达Dp87的细胞首先随机出现在聚集流中，随后聚集在聚集中心的基底部分，延续了上述通过分选分化细胞形成分化模式的概念。