Genetic Analysis of C. elegans fat regulatory network

线虫脂肪调节网络的遗传分析

• 批准号: 6948787
• 负责人: Kaveh Ashrafi
• 金额: $ 30.08万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-20 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6948787
• 关键词: Caenorhabditis elegans; RNA interference; animal genetic material tag; appetite regulatory center; bioenergetics; biological signal transduction; carbohydrate metabolism; dietary lipid; fats; fatty acids; gene expression; gene induction /repression; green fluorescent proteins; high throughput technology; homeostasis; insulin; nutrient intake activity; polymerase chain reaction; regulatory gene; serotonin; starvation; sterols

DESCRIPTION (provided by applicant): There is mounting evidence that fat regulation involves a complex interplay between the feeding regulatory centers in the nervous system and the regulated transport, partitioning, storage, and utilization of stored fat. It is thought that this homeostatic system has evolved to ensure survival by maintaining energy reservoirs. However, in times of plentiful nutrient supplies, this homeostatic system can cause obesity in individuals with propensity for maintaining large energy stores. Obesity is associated with major heath epidemics worldwide. C. elegans provides an opportunity to identify and analyze fat regulatory genes. Importantly, these analyses are conducted in intact animals in the context of the homeostatic network. Previously, genome-wide RNAi approaches identified over 400 genes that, when inactivated, affect body fat content in C. elegans. These include components of neuroendocrine signaling, transcription, and metabolism. These findings highlight the shared ancestry of C. elegans and mammalian fat regulation and identify many novel pathways. Based on epistasis analyses and mammalian homology searches, 120 priority candidates have been identified. To understand the modes of function and regulation of these genes in intact organisms, i) feeding and locomotary rates of RNAi exposed animals will be determined, ii) quantitative RT-PCR assays will be used to monitor expression levels of a panel of fatty acid, sterol, and sugar metabolic enzymes in RNAi exposed animals, iii) genes identified to affect similar processes will be grouped into genetic pathways, iv) sites of function of fat genes and their products will be determined by GFP tag fusions, iv) these GFP-tag reporters and RT-PCR assays will be used to identify the fat gene inactivations that affect expression levels and/or localizations of the other fat regulatory genes. Similarly, impact of starvation or defects in insulin and serotonin signaling pathways on the fat regulatory genes will be assessed.

描述（由申请人提供）： 越来越多的证据表明，脂肪调节涉及神经系统中的摄食调节中心与储存脂肪的调节运输、分配、储存和利用之间的复杂相互作用。据认为，这种自我平衡系统已经进化到通过维持能量库来确保生存。然而，在营养供应充足的时候，这种体内平衡系统可能会导致个体肥胖，倾向于维持大量的能量储存。肥胖与世界范围内的主要健康流行病有关。C.线虫提供了一个机会，以确定和分析脂肪调控基因。重要的是，这些分析是在稳态网络的背景下在完整的动物中进行的。以前，全基因组RNAi方法鉴定了400多个基因，当这些基因失活时，会影响C.优雅的这些包括神经内分泌信号传导、转录和代谢的组成部分。这些发现强调了C. elegans和哺乳动物的脂肪调节，并确定了许多新的途径。基于上位性分析和哺乳动物同源性搜索，已确定120个优先候选人。为了理解这些基因在完整生物体中的功能和调节模式，i）将确定RNAi暴露动物的摄食率和摄食率，ii）将使用定量RT-PCR测定来监测RNAi暴露动物中一组脂肪酸、固醇和糖代谢酶的表达水平，iii）将鉴定为影响类似过程的基因分组为遗传途径，iv）通过GFP标签融合物确定脂肪基因及其产物的功能位点，iv）这些GFP标签报告基因和RT-PCR测定将用于鉴定影响其它脂肪调节基因的表达水平和/或定位的脂肪基因失活。类似地，将评估饥饿或胰岛素和5-羟色胺信号传导途径缺陷对脂肪调节基因的影响。