Molecular mechanisms for the regulation of sexual development in response to the external signals in fission yeast

根据营养条件，分裂酵母细胞启动新一轮的细胞周期或性发育。当单倍体细胞交配时，它们通过分泌和接受交配信息素进行交流。阐明这些信号转导系统和性别分化的分子机制将大大增加细胞生物学领域的研究。这个项目就是为了这个目的而进行的。所得主要结果总结如下：1. 我们克隆了蛋白激酶a催化亚基的裂变酵母基因，通过对该克隆的分析证实，cAMP是介导营养条件信号的第二信使。2. 研究结果表明，mei2基因产物是一种rna结合蛋白，是分裂酵母减数分裂起始的关键因子。Mei2蛋白不仅在减数分裂前DNA合成之前，而且在减数分裂I之前都是必需的，一个新的RNA物种（meiRNA）与Mei2合作促进减数分裂I已经被发现和鉴定。3. 我们从拟南芥中克隆了一些基因，这些基因可以跨补在交配和/或减数分裂中有缺陷的裂变酵母突变体。这些基因是否参与植物性发育的控制目前还在研究中。对动物基因的筛选也在进行中。

The fission yeast cells initiate either a new round of the cell cycle or sexual development depending on the nutritional conditions. When haploid cells mate, they communicate by secreting and accepting the mating pheromones.Elucidation of the molecular mechanisms underlying these signal transduction systems and sexual differentiation will add much to the field of cell biology.This project was performed to this purpose. The major results obtained are summarized as follows. 1. We cloned the fission yeast gene for the catalytic subunit of protein kinase A.Analysis using this clone confirmed that cAMP serves as a second messenger that mediates the signal from the nutritional conditions. 2. We showed that the mei2 gene product, which is a key factor essential for the initiation of meiosis in fission yeast, is an RNA-binding protein. Mei2 protein turned out to be required not only prior to premeiotic DNA synthesis but also prior to meiotic division I.A novel RNA species (meiRNA) that cooperates with Mei2 to promote meiotic division I has been identified and characterized. 3. We cloned a number of genes from a plant Arabidopsis thaliana that can transcomplement fission yeast mutants defective in mating and/or meiosis. Whether these genes are involved in control of sexual development in the plant is currently under study. Screening for animal genes that transcomplement fission yeast mutants is also in progress.