DIFFERENTIAL EXPRESSION OF THE DIVERSE PLANT ACTIN GENES

高等植物含有一个肌动蛋白基因家族， 不同的类。 有人提出，古老的植物肌动蛋白类 基因在维管植物的进化过程中一直被保留下来， 具有独特的基因调控模式和/或编码肌动蛋白， 独特的功能。 这项研究的一个主要目标是确定 这些类别相对于细胞、组织和 器官类型和发育。 的初始物理表征 拟南芥中的几个肌动蛋白基因和不同的蛋白质同种变体表明， 它是追求这一目标的理想工厂，其结果将是 大多数被子植物的代表。 一套目标的重点是 描绘不同基因家族的表达模式 Arabidopsis的成员。 为了实现这一点，mRNA表型将是 确定了各种细胞类型和组织， root. 聚合酶链反应（PCR）介导的转录物测序 来自单个细胞类型或组织的mRNA将明确地定义 表型。 内部对照将用于定量表达。 一 第二个目标集中在定义肌动蛋白在不同细胞中的作用， 组织和植物发育。 具体目标包括： 肌动蛋白突变体的类型。 肌动蛋白中T-DNA插入的杂合植物 基因将从大量的T-DNA插入突变体中分离出来 采用PCR筛选方法。 另一种方法是使用马赛克 植物肌动蛋白突变体以保持亲本生物体的活力。 一 与反义肌动蛋白融合的休眠指示剂β-葡萄糖醛酸酶（GUS）基因 RNA将被转录物中Ds转座子的丢失激活 领袖 这种方法的另一个优点是， 突变表型的发育模式。 植物、器官和细胞 将表征显示突变表型或表达GUS的谱系 细胞化学和生物化学用于肌动蛋白表达。 最终目标是 将肌动蛋白基因家族成员的多样性与 维管植物细胞类型和组织的起源， 提出了植物肌动蛋白的功能。

Higher plants contain a family of actin genes made up of many ancient and diverse classes. It is proposed that the ancient classes of plant actin genes have been preserved throughout vascular plant evolution because they have unique patterns of gene regulation and/or encode actin proteins with unique functions. A major goal of this research is to define the differential expression of these classes with respect to cell, tissue and organ type, and development. An initial physical characterization of several actin genes and diverse protein isovariants in Arabidopsis suggests it is the ideal plant in which to pursue this goal and that results will be representative of most angiosperms. One set of objectives focuses on delineating the patterns of expression for the different gene family members in Arabidopsis. To accomplish this an mRNA phenotype will be determined for variety of cell types and tissues beginning with those in root. Polymerase chain reaction (PCR) mediated sequencing of transcripts from a single cell type or tissue will unambiguously define the mRNA phenotypes. Internal controls will be used to quantify expression. A second goal focus on defining the roles for actins in different cells and tissues and in plant development. Specific objectives include making two types of actin mutants. Plants heterozygous for T-DNA insertions in actin genes will be isolated from a large population of T-DNA insertion mutants using a PCR screening method. An alternative approach makes use of mosaic plant actin mutants to preserve the viability of the parent organism. A dormant indicator beta-glucuronidase (GUS) gene fused to an antisense actin RNA will be activated by the loss of a Ds transposon in the transcript leader. This approach has the additional advantage of expressing the mutant phenotype in a developmental pattern. Plants, organs and cell lineages showing mutant phenotype or expressing GUS will be characterized cytochemically and biochemically for actin expression. An ultimate goal is to correlate the diversification of actin gene family members with the origin of cell types and tissues in vascular plants and with the numerous functions proposed for plant actins.