HUA1 AND HUA2 IN ARABIDOPSIS FLOWER DEVELOPMENT

HUA1 和 HUA2 在拟南芥花发育中的作用

• 批准号: 6743667
• 负责人: Xuemei Chen
• 金额: $ 21.76万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6743667
• 关键词: Arabidopsis; DNA binding protein; alleles; developmental genetics; gene expression; gene interaction; genetic mapping; histogenesis; molecular cloning; plant genetics; plant growth /development; plant morphology; polymerase chain reaction; protein protein interaction; yeast two hybrid system

We are interested in a fundamental issue in the development of multicellular organisms, i.e., how a few undifferentiated cells assume their identities and form distinct patterns. We have chosen to address this issue in the context of Arabidopsis flow development. In particular, we are studying how precursor cells assume their identifies and develop into stamens and carpels, the male and female reproductive organisms of the flower. For a long time, AG, a MADS domain transcription factor, was the only known protein involved in this developmental process. It is not clear how a single transcription factor leads to the eventual formation of complex organs such as stamens and carpels. It is our long-term goal to fully dissect the AG pathway in order to understand this complex developmental process. Two new members of the AG pathway, HUA1 and HUA2, were isolated from our enhancer screen using a weak ag allele. HUA2 was cloned with a map-base strategy. It codes for a putative transcription factor and transcriptional co-activator of AG. Significant progress has been made towards the cloning of HUA1. This proposal is aimed at uncovering the molecular mechanisms underlying the functions of HUA1 and HUA2 in Arabidopsis flower development. First, HUA2 will be studied at the protein level. HUA2 protein localization pattern within the plant will be determined. Experiments will be performed to study the physical interaction between AG and HUA2, which was observed in our preliminary studies. Our genes whose products interact with HUA2 will be isolated with a yeast two-hybrid screen. Second, HUA1 will be cloned and studied at the molecular level. Its RNA localization patterns within the plant will be determined. Potential interactions among HUA1, HUA2 and AG proteins will be investigated. Third, additional mutant alleles of HUA1 and HUA2 will be isolated, especially severe loss-of-function mutations, which will help solve some pending issues regarding the functions of HUA1 and HUA2 in the AG pathway. A combination of a molecular screen of T-DNA insertional lines and a Hua1 Hua2 enhancer screen will be employed for this purpose. A detailed understanding of a homeotic pathway in Arabidopsis will be an invaluable addition to our knowledge of developmental process in general. Plant and animal homeotic pathways can be compared to derived evolutionary principles. In addition, studying plant development in a simple organism like Arabidopsis will likely expedite our understanding of more complicated organisms such as humans. In light of the fact that HUA2 shares common motifs with genes in C. elegans, Drosophila, mice and humans, it will not be surprising that the molecular functions of some plant genes in homeotic pathways are conserved in animals.

我们对多细胞生物的发展中的一个基本问题感兴趣，即，一些未分化的细胞如何假设其身份并形成不同的模式。我们选择在拟南芥流量发展的背景下解决这个问题。特别是，我们正在研究前体细胞如何假定其识别并发展成雄蕊和皮肤，即花的雄性和女性生殖生物。长期以来，AG是一种MADS域转录因子，是该发育过程中唯一已知的蛋白质。目前尚不清楚单个转录因子如何导致雄蕊和皮肤等复杂器官的最终形成。我们的长期目标是完全剖析AG途径，以了解这一复杂的发展过程。使用弱AG等位基因从我们的增强子屏幕中分离出AG途径的两个新成员HuA1和HuA2。 Hua2用MAP基策略克隆。 它代码为AG的推定转录因子和转录共激活因子。在Hua1的克隆方面取得了重大进展。该建议旨在发现HuA1和HuA2在拟南芥花发展中的功能的基础机制。首先，将在蛋白质水平上研究HUA2。将确定植物内的HUA2蛋白定位模式。将进行实验以研究AG和HUA2之间的物理相互作用，这在我们的初步研究中观察到。我们的产品与HUA2相互作用的基因将与酵母双杂交筛选分离。其次，将HUA1克隆并在分子水平上进行研究。将确定其在植物中的RNA定位模式。将研究HUA1，HUA2和Ag蛋白之间的潜在相互作用。第三，将分离出HUA1和HUA2的其他突变等位基因，尤其是严重的功能丧失突变，这将有助于解决有关HUA1和HUA2在AG途径中的功能的待处理问题。将使用T-DNA插入线的分子屏幕和HUA1 HUA2增强子筛选的组合。对拟南芥中同源途径的详细理解将是我们一般对发展过程的知识的宝贵补充。植物和动物同源途径可以与衍生的进化原理进行比较。此外，研究拟南芥等简单生物体中的植物发育可能会加快我们对更复杂的生物（如人类）的理解。鉴于HUA2在秀丽隐杆线虫，果蝇，小鼠和人类中与基因共有共同基序这一事实，毫不奇怪的是，某些植物基因在同源途径中的分子功能是在动物中保守的。