TEMPORAL AND SPATIAL GENE REGULATION--BACILLUS SUBTILIS

枯草芽孢杆菌的孢子形成相对简单， 一种涉及基因高度有序程序的发育过程 表达和形态变化。 这项研究的目的是 了解基因表达如何与形态变化相结合， 芽孢杆菌产孢产生正确的时空格局 基因表达。 这些研究具有广泛的意义，因为所有 经历发育的生物体必须调节基因表达系统， 揭示发育基因调控的基本机制。 在孢子形成的早期，子染色体被分成两个 区室，以及随后的基因表达模式，在每个 隔间是不同的。 遗传学研究表明， 母细胞隔室以某种方式与发生在 前孢子室 最近发现的两个 母细胞特异性基因表达的调节因子提供了两种可能的 耦合现象的机制。 其中一种调节蛋白是 RNa聚合酶的σ亚基（称为sigmak），其可以合成 作为非活性前体。 将其处理为活动形式可能是 与前孢子事件有关。 另一种调节蛋白（称为 14 kDa蛋白）是一种非sigma转录因子，其失活具有 已经提出的实验旨在测试这些假设，并 定义这两种蛋白质在时间和空间基因中的作用 调控 具体地，1）在一个或多个细胞中的14 kDa蛋白的结合位点， 它抑制的启动子将发生突变，看看启动子现在是否变成 活性较早并且与前孢子事件解偶联，2）抗 将制备14 kDa蛋白并用于测定其量， 3）sink基因（编码sigmak）将被定位在 将测试与诱导型启动子融合的pro-sigmak的活性。 将制备sigmak前体抗体，以直接检测sigmak是否为 在孢子形成过程中作为前体产生。 如果pre-sigmak处于非活动状态， 截短的活性Sigk基因将与诱导启动子融合。 的 在细胞中随意产生pro-sigmak或sigmak的能力允许 测试耦合中是否涉及pro-sigmak处理 隔舱之间。

Sporulation of the bacterium Bacillus subtilis is a relatively simple developmental process that involves a highly ordered program of gene expression and morphological change. The goal of this research is to understand how gene expression is coupled to morphological change during Bacillus sporulation to produce the correct pattern of temporal and spatial gene expression. These studies are of broad significance since all organisms that undergo development must regulate gene expression system to uncover fundamental mechanisms involved in developmental gene regulation. Early in sporulation, the daughter chromosome are partitioned to two compartments, and the subsequent pattern of gene expression in each compartment is distinct. Genetic studies suggest that gene expression in the mother cell compartment is somehow coupled to events occurring in the forespore compartment. The properties of two recently discovered regulators of mother cell-specific gene expression provide tow plausible mechanisms for the coupling phenomenon. One of the regulatory proteins is a sigma subunit of RNa polymerase (called sigmak) that may be synthesized as an inactive precursor. Its processing to the active form could be coupled to forespore events. The other regulatory protein (called the 14kDa protein) is a non-sigma transcription factor whose inactivation has been proposed experiments are designed to test these hypotheses and to define the roles of these two proteins in temporal and spatial gene regulation. Specifically, 1) the binding site of the 14kDa protein in a promoter it represses will be mutated to see if the promoter now becomes active earlier and is uncoupled form forespore events, 2) antibody to the 14kDa protein will be prepared and used to determine its amount and location during sporulation, 3) the sink gene (encoding sigmak) will be fused to an inducible promoter and pro-sigmak will be tested for activity. Antibody to pro-sigmak will be prepared to test directly whether sigmak is made as a precursor during sporulation. If pre-sigmak is inactive, a truncated, active sigk gene will be fused to an induced promoter. The ability to produce pro-sigmak or sigmak at will in cells will permit testing of whether pro-sigmak processing is involved in the coupling between compartments.