Molecular Genetics of Arabidopsis Thaliana

拟南芥是一种杂草，是芥菜家族的一员。与已在分子水平上描述的其他植物不同，拟南芥基因组较小，重复DNA很少，主要是单拷贝基因，生命周期相对较短。因此，对于一种植物来说，它非常适合进行遗传和分子研究。这里提出了两个独立的项目，都是为了了解开花植物拟南芥的遗传过程。第一个项目涉及开发和使用反式作用调控突变的基因选择，这些突变减少或消除两个不同胚胎特异性基因启动子中的一个或两个的表达。当获得这样的突变时，他们将在基因和分子水平上进行研究。第二个项目是研究导致花器官同源异型转化的一系列拟南芥突变。这些研究涉及已知突变的基因特征，新突变的分离，以及导致这些突变的一个或多个基因的分子克隆。第一个项目的目标是了解组织特异性基因表达的机制，第二个项目的目标是在分子水平上了解形态发生中的模式形成。植物为理解遗传印记的发育程序提供了独特的优势，这导致了一个成熟的有机体，但由于基因组的复杂性和大小，这种研究不能在大多数植物中进行。拟南芥作为实验系统提供了植物的优点，而不是缺点。梅耶罗维茨博士和他的同事们成功完成这些项目，不仅可以产生重要的信息，还可以为探索发育遗传学提供一个只有黑腹果蝇能与之匹敌的实验系统。

Arabidopsis thaliana is a weed, a member of the mustard family. In contrast to other plants which have been characterized at the molecular level, Arabidopsis has a small genome, very little repetitive DNA, primarily single copy genes and a relatively short life cycle. Thus, for a plant, it is ideally suited for genetic and molecular studies. Two independent projects are proposed here, both aimed toward an understanding of the genetic processes of the flowering plant Arabidopsis thaliana. The first project involves development and use of a genetic selection for trans-acting regulatory mutations that reduce or eliminate expression from one or both of two different embryo-specific gene promoters. When such mutations are obtained they will be studied both at the genetic and molecular level. The second project is the study of a series of Arabidopsis mutations that cause homeotic transformations of floral organs. These studies involve the genetic characterization of mutations that are already known, isolation of new mutations, and molecular cloning of one or more of the genes responsible for these mutations. The goal of the first project is to understand the mechanism of tissue specific gene expression and the second to understand pattern formation in morphogenesis at a molecular level. Plants offer unique advantages for understanding the genetically imprinted program of development which leads to a mature organism but such studies cannot be done in most plants because of genome complexity and size. Arabidopsis as are experimental system offers the advantages of plants without the disadvantages. The successful completion of these projects by Dr. Meyerowitz and his associates could not only produce significant information but provide an experimental system equalled only by Drosophila melanograster for the exploration of developmental genetics.