GENETICS OF AGAMOUS ACTION IN ARABIDOPSIS DEVELOPMENT

拟议实验的长期目标是了解 遗传和分子机制的模式形成在多细胞 有机体选择用于实验室实验的生物体是 开花植物拟南芥，要研究的模式是 花的器官特性和分化的细胞类型的模式。 选择花和拟南芥是为了实验方便 和速度：植物很小，生长迅速，有强大的遗传学， 非常适合于简单的分子克隆和转化。花 因为它们是高度模式化的， 所有生物体发育模式形成的特征，但包含 细胞类型很少，发育迅速，对植物不重要， 生存能力。因此，具有异常花朵的突变体可以很容易地被 获得，生长和研究。因果分析的健康相关性 模式形成是指出生缺陷，其中模式已经形成 不正确;遗传性发育障碍，其中调节 基因，如本建议中强调的那些基因，会发生异常作用; 肿瘤，由逃避正常阴性对照的细胞组成 对细胞分裂、细胞分化和细胞迁移的影响。 所提出的具体实验是为了了解调节和 花器官识别和调节基因AGAMOUS的活性。 AGAMOUS在花型形成中起着三个关键作用： 为指定雄蕊和心皮所必需的，这是必要的， 足以负调控指定萼片的基因， 花瓣，它是必要的适当的细胞分裂模式， 花原基发育中心。AGAMOUS的蛋白质产品 基因是一种DNA结合转录激活因子， 氨基酸序列水平与人转录调节因子， 调节c-fos癌基因的血清反应因子，以及MEF-2， 调节肌肉发育三组实验是 提出了首先是理解空间特定的表达 的AGAMOUS。这在很大程度上是由两个负调节器解释的 AGAMOUS的基因。编码这些负 将研究和克隆调节剂。第二，AGAMOUS的活动 将研究在确定器官身份方面的作用。新的方法已经 开发并将应用于寻找下游基因激活 由GA MO US基因产物所控制。最后，细胞-细胞的作用 在发展中的花通信将研究通过使遗传 马赛克，再次使用新的方法，已经设计了这种类型的 实验

The long-term objective of the proposed experiments is to understand the genetic and molecular mechanisms of pattern formation in multicellular organisms. The organism chosen for laboratory experiments is the flowering plant Arabidopsis thaliana, and the patterns to be studied are the patterns of organ identity and differentiated cell type in flowers. The choice of flowers and of Arabidopsis is for experimental convenience and speed: the plant is small, grows quickly, has powerful genetics, and is well-suited for facile molecular cloning and transformation. Flowers are to be used because they are highly patterned and demonstrate the key features of developmental pattern formation in all organisms, yet contain very few cell types, develop rapidly, and are inessential for plant viability. Mutants with abnormal flowers can therefore be easily obtained, grown, and studied. The health relevance of causal analyses of pattern formation is to birth defects, in which patterns have formed incorrectly; to inherited developmental disorders, in which regulatory genes such as those emphasized in this proposal act aberrantly; and to tumors, which consist of cells that have escaped normal negative controls on cell division, cellular differentiation, and cellular migration. The specific experiments proposed are to understand the regulation and activities of the floral organ-identity and regulatory gene AGAMOUS. AGAMOUS plays three key roles in floral pattern formation: it is necessary for specifying the stamens and carpels, it is necessary and sufficient to negatively regulate the genes that specify sepals and petals, and it is required for appropriate cell division patterns in the center of developing flower primordia. The protein product of the AGAMOUS gene is a DNA-binding transcriptional activator that is related at the level of amino acid sequence to human transcriptional regulators such as serum response factor, which regulates the c-fos oncogene, and MEF-2, which regulates muscle development. Three sets of experiments are proposed. The first are to understand the spatially-specific expression of AGAMOUS. This is in large part explained by two negative regulators of AGAMOUS that have been found. The genes encoding these negative regulators will be studied and cloned. Second, the activity of AGAMOUS in specifying organ identity will be studied. New methods have been developed and will be applied to finding the downstream genes activated by the A GA MO US gene product. Finally, the role of cell-cell communication in developing flowers will be studied by making genetic mosaics, again using new methods that have been devised for this type of experiment.