GENE EXPRESSION DURING SPORULATION

枯草芽孢杆菌是一种原始的细胞系统 差异化。孢子形成的一个关键的早期阶段是不对称的 已找到组织。这就产生了两种不同的细胞类型，母细胞 细胞和前孢子有着截然不同的发育命运。 母细胞是发育所必需的，但最终会裂解。 孢子的形成需要复杂的基因表达模式。主 这里要解决的问题是如何编排复杂的模式 在从单细胞状态到单细胞状态的发育转变中 母细胞吞噬前孢子。这包括以下问题 基因表达的区分性和基因表达的协调性 有形态上的变化。 SpoIIA和SpoIIG基因座在孢子形成过程中占有举足轻重的地位。 它们包括RNA聚合酶西格玛因子F的结构基因 和E。这些基因座在隔膜形成之前被转录。 Sigma因子可能被隔膜形成所激活。他们的活动 最初不是划分的，而是变成划分的，F 在前孢子中活跃，在母细胞中活跃。SigmaF和SigmaE 被认为是转录所需的，直接或间接 在所有后来表达的产孢子基因中。有人建议对基因进行鉴定 参与SigmaF和SigmaE的激活，并对其进行表征 基因以及我们最近发现的一种基因，spIIR， 将Pro-SigmaE处理为SigmaE所需。现建议： 研究基因表达的区分化，并确定 并研究区划所需的基因。现建议： 研究EsigmaF转录的基因。此外，还建议 调查IIA转录的控制，考虑到 控制器中存在冗余和反馈回路的可能性。

Formation of spores by Bacillus subtilis is a primitive system of cell differentiation. A crucial early stage of sporulation is an asymmetrically located division. This gives rise to two distinct cell types, the mother cell and the prespore which have radically different developmental fates. The mother cell is required for the development but ultimately lyses. Spore formation requires a complex pattern of gene expression. The main problem being addressed here is how that complex pattern is orchestrated during the developmental transition from the single-cell state tot he engulfment of the prespore by the mother cell. This includes questions of compartmentalization of gene expression and coordination of gene expression with morphological changes. The spoIIA and spoIIG loci occupy a pivotal position in spore formation. They include the structural genes for the RNA polymerase sigma factors F and E, respectively. The loci are transcribed before the septum is formed. The sigma factors may be activated by septum formation. Their activities are initially not compartmentalized, but become compartmentalized, with F being active in the prespore and E in the mother cell. SigmaF and sigmaE are thought to be required, directly or indirectly, for the transcription of all later expressed sporulation genes. It is proposed to identify genes involved in the activation of sigmaF and sigmaE, and to characterize those genes as well as a gene, spoIIR, that we have recently identified as being required for processing of pro-sigmaE to sigmaE. It is proposed to investigate the compartmentalization of gene expression, and to identify and study genes required for compartmentalization. it is proposed to investigate genes transcribed by EsigmaF. It is also proposed to investigate the controls of IIA transcription, taking account of the possibilities of redundancies and feed back loops in the controls.