Functional analysis of microRNA genes in Drosophila

果蝇microRNA基因的功能分析

• 批准号: 6843745
• 负责人: Victor Ambros
• 金额: $ 27.95万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6843745
• 关键词: Caenorhabditis elegans; Drosophilidae; RNA; biological signal transduction; ecdysone; functional /structural genomics; gene expression; gene mutation; genetic regulation; genetic translation; green fluorescent proteins; messenger RNA; northern blottings; polymerase chain reaction; posttranslational modifications

DESCRIPTION (provided by applicant): The small regulatory RNA products of the lin-4 and let-7 genes of C. elegans are microRNAs (miRNAs) that control developmental timing in worm larvae. lin-4 and let-7 function by repressing the translation of specific target messenger RNAs via RNA: RNA antisense base-pairing. lin-4, let-7 and certain other miRNAs are evolutionarily conserved among worms, insects and vertebrates, and in some cases, homologs are expressed in similar profiles in diverse animals. These conserved microRNAs may play similar roles in the post-transcriptional control of gene expression during development of vertebrates and invertebrates. This project is designed to determine the in vivo function of four developmentally regulated, evolutionarily conserved, microRNAs in Drosophila melanogaster, let-7, mir-34, mir-100, and mir-125 (the fly ortholog of lin-4). The let-7, mir-125 and mir-100 genes are clustered in the Drosophila genome, and are up-regulated by ecdysone signaling in conjunction with a major developmental transition in flies, larva-to-adult metamorphosis. By contrast, mir-34 expression is down-regulated by ecdysone at the onset of metamorphosis. The goals of this project are to 1) isolate loss-of-function mutations in let-7, mir-125, mir-100, and mir-34, and analyze any resulting defects in fly development; 2) determine the temporal and spatial patterns of expression of let-7, mir-125, mir-100, and mir-34 during Drosophila development; 3) analyze developmental defects resulting from the over-expression and ectopic expression of these miRNAs; 4) identify messenger RNAs that are antisense targets of let-7, mir-125, mir-100, and mir-34; 5) identify additional evolutionarily conserved miRNA genes that are activated or repressed by ecdysone signaling during Drosophila development. This project will exploit Drosophila genetics to define the biological processes that evolutionarily conserved miRNAs control and will illuminate molecular mechanisms fundamental to animal development, including mammals, and insects significant to human health.

描述（由申请人提供）： 线虫 lin-4 和 let-7 基因的小调节 RNA 产物是控制蠕虫幼虫发育时间的 microRNA (miRNA)。 lin-4 和 let-7 通过 RNA：RNA 反义碱基配对抑制特定靶标信使 RNA 的翻译来发挥作用。 lin-4、let-7 和某些其他 miRNA 在蠕虫、昆虫和脊椎动物中进化保守，并且在某些情况下，同源物在不同动物中以相似的图谱表达。这些保守的 microRNA 可能在脊椎动物和无脊椎动物发育过程中基因表达的转录后控制中发挥相似的作用。该项目旨在确定果蝇中四种发育调控、进化保守的 microRNA（let-7、mir-34、mir-100 和 mir-125（lin-4 的果蝇直系同源物））的体内功能。 let-7、mir-125 和 mir-100 基因聚集在果蝇基因组中，并通过蜕皮激素信号传导以及果蝇幼虫到成虫变态的主要发育转变而上调。相比之下，mir-34 的表达在变态开始时被蜕皮激素下调。该项目的目标是 1) 分离 let-7、mir-125、mir-100 和 mir-34 中的功能丧失突变，并分析果蝇发育中产生的任何缺陷； 2)确定果蝇发育过程中let-7、mir-125、mir-100和mir-34表达的时间和空间模式； 3）分析这些miRNA的过度表达和异位表达导致的发育缺陷； 4) 鉴定作为let-7、mir-125、mir-100和mir-34反义靶标的信使RNA； 5) 鉴定在果蝇发育过程中被蜕皮激素信号激活或抑制的其他进化上保守的 miRNA 基因。该项目将利用果蝇遗传学来定义进化上保守的 miRNA 控制的生物过程，并将阐明动物发育的基本分子机制，包括对人类健康至关重要的哺乳动物和昆虫。