MOLECULAR BIOLOGY OF ADHI MUTANTS

我们计划研究玉米中的厌氧蛋白基因， 由厌氧应激诱导表达的基因。 我们的研究将是 主要涉及这些基因之一，乙醇脱氢酶1（Adh 1）。 存在充分表征的突变等位基因和自然发生的 Adh 1的变体，其表现出改变的定量和器官特异性 监管行为为这一系统提供了令人兴奋的可能性， 真核基因调控研究。 我们将使用重组DNA 纯化含有正常和突变等位基因的基因组DNA片段的技术 Adh 1的 我们将确定Adhl基因突变的性质 导致调节行为改变的等位基因。 我们将使用分子 与ADH 1-mRNA互补的克隆DNA探针，以测量 厌氧胁迫下ADH 1-mRNA及其前体 通过比较突变体 等位基因与它们的“正常”祖先等位基因，我们将确定哪个过程 导致可翻译的ADH 1-mRNA的产生在每个突变体中被改变。 从改变的结构和改变的功能的相关性，我们将能够 以确定Adh 1基因的特定调控功能区域。 我们将 还研究了DNA甲基化和染色质结构在 差异基因表达 Adh 1等位基因和变体的可用性 具有不同的定量和器官特异性表达水平， 提供了关于DNA甲基化作用的新信息， 染色质结构

We propose to study the anaerobic protein genes in maize, a group of twenty genes whose expression is induced by anaerobic stress. Our studies will be primarily concerned with one of these genes, alcohol dehydrogenase 1 (Adh1). The existence of well-characterized mutant alleles and naturally occurring variants of Adh1 which exhibit altered quantitative and organ-specific regulatory behavior provide this system with exciting possibilities in the investigation of eucaryotic gene regulation. We will use recombinant DNA technology to purify genomic DNA fragments containing normal and mutant alleles of Adh1. We will determine the nature of the mutational changes in the Adhl alleles which result in altered regulatory behavior. We will use molecularly cloned DNA probes complementary to ADH1-mRNA to measure the accumulation of ADH1-mRNA and its precursors during anaerobic stress. By comparing mutant alleles with their "normal" progenitor alleles we will determine which process leading to the production of translatable ADH1-mRNA is altered in each mutant. From the correlation of altered structure with altered function we will be able to define regions of specific regulatory function at the Adh1 gene. We will also investigate the roles of DNA methylation and chromatin structure in differential gene expression. The availability of Adh1 alleles and variants with different quantitative and organ-specific levels of expression should provide new kinds of information about the roles of DNA methylation and chromatin structure.