RAPID ISOLATION OF DIET-RESPONSIVE OBESITY GENES

个体体重通过以下各项的复杂混合来确定： 环境和基因的影响。人口平均数可以证明 环境的影响，而统计遗传学表明生物 对肥胖的影响。然而，这些方法不能解释个体 体重差异，即，为什么有些人肥胖有些人不肥胖 肥胖的个体原因可能通过找到特定的基因来确定 与自然变异（等位基因），其功能不同的人。许多 肥胖基因已经被发现，但其他基因仍未被发现。的 主要研究者（PI）的目标是在体内识别肥胖基因， 了解他们如何影响身体脂肪积累，并继续他们的研究。 体外研究解偶联蛋白（UCPs）的结构和功能， 是肥胖症的候选基因为了研究体重调节的基础， PI将：1）确定同类小鼠肥胖的基因 模型，2）研究解偶联蛋白质作用的机制，3）寻找 同系小鼠品系中受饮食调控的新基因。PI和他的 合作者最近证明，C7.H1同源株， 比其背景菌株明显更瘦，具有两个连锁的染色体 肥胖基因位点，尽管与背景基因相同率高达99%。 他们现在提出生产五种亚同源菌株（用较小的供体 区域）以识别每个位点的基因。UCP 2和3以及tubby 是远端位点的位置候选者。PI将通过以下方式测试他们的角色： 确定同源和背景菌株的序列， mRNA和蛋白质水平的测量。他们还将利用mRNA表达 从C7.H1同源和亚同源菌株中鉴定新的 肥胖候选基因PI将扩展他对UCP 2 -3的研究， H1同源模型的候选基因， UCPs的结构/功能研究。解偶联蛋白可能影响身体 体重和代谢率降低的功效与线粒体 将卡路里转化为ATP。已公布的数据和初步数据， 建议，证明UCP是由几个配体，如 类维生素A、核苷酸和脂肪酸。PI将测试质子传输 脂质体中已确定和新候选UCP的活性，并将研究 电子顺磁定向自旋标记（SDSL）的UCP结构 共振（EPR）。这些研究将与现场指导的 诱变，以测试有关质子运输机制的假设。

Individual body weights are determined by a complex blending of environmental and genetic influences. Population averages can demonstrate environmental influences while statistical genetics demonstrates biological influences on obesity. However, these methods cannot explain individual differences in body weight, i.e., why some people are obese and some are not. The individual causes for obesity may be determined by finding specific genes with natural variants (alleles) whose function varies among people. Many obesity genes have been identified, but others remain undiscovered. The principal investigator's (PI) goals are to identify obesity genes in vivo, to understand how they influence body fat accumulation, and to continue their in vitro work on the structure and function of uncoupling proteins (UCPs), which are candidate obesity genes. To study the basis for body weight regulation, the PI will: 1) determine the gene(s) that underlies obesity in a congenic mouse model, 2) study the mechanisms for uncoupling protein action, and 3) search for novel genes regulated by diet in congenic mouse strains. The PI and his collaborators have recently demonstrated that the C7.H1 congenic strain, which is significantly leaner than its background strain, has two linked chromosomal obesity loci, despite being 99 percent genetically identical to the background. They now propose to produce five subcongenic strains (with smaller donor regions) to identify the gene that underlies each locus. UCP2 and 3 and tubby are positional candidates for the distal locus. The PI will test their role by determining sequence from the congenic and background strains and by measurement of mRNA and protein levels. They will also use mRNA expression profiles from the C7.H1 congenic and subcongenic strains to identify novel obesity candidate genes. The PI will extend his studies of UCP2-3 as positional candidate genes for the C7.H1 congenic model by the application of structure/function studies of UCPs. Uncoupling proteins may influence body weight and metabolic rate by decreasing the efficacy with which mitochondria convert calories into ATP. Published data, and preliminary data in this proposal, demonstrate that UCPs are regulated by several ligands, such as retinoids, nucleotides, and fatty acids. The PI will test proton transport activity of established and novel candidate UCPs in liposomes and will study UCP structure by Site-Directed Spin Labeling (SDSL) Electron Paramagnetic Resonance (EPR). These studies will be coordinated with site-directed mutagenesis to test the hypotheses about mechanisms for proton transport.