Positional cloning of obesity genes from congenic mice

定位克隆--通过定位肥胖性状和肥胖基因的重合性来鉴定肥胖基因， 一个特定的染色体区域，提供了一个强大的方法来发现新的肥胖基因， 对导致肥胖的机制的新见解。小鼠已被用于第一次确定更多的 人类肥胖基因比任何其他模型。该提案的目标是使用定位克隆方法， 在小鼠同类品系中鉴定肥胖基因。同类小鼠品系与背景相同 除了来自供体菌株的染色体区域之外，表型差异的同源和 背景菌株与供体菌株之间的差异是由于供体菌株的等位基因具有与背景菌株不同的功能效应。 为这一提议做出贡献的两个实验室已经鉴定出几种小鼠同源品系， 小鼠2号染色体上与人类同源区域中统计学显著的肥胖表型 20号染色体，其中几个肥胖数量性状基因座已被定位。我们的假设是 同源供体区域中的一个或多个基因或转录物影响肥胖。我们的具体工作 一种假设是，肥胖症的基因/转录本可以在大多数同类中鉴定出来。我们提出 七个具体目标。我们将：确定饮食，性别和年龄对肥胖的影响，在创始同源（目的 1），通过与更小的基因进行同源繁殖来鉴定含有肥胖基因的最小染色体位点， 保留肥胖表型的供体区域（目标2），发现差异表达的供体区域基因， 使用来自八种肥胖组织的RNA的全基因组微阵列（Aim 3）， 基因（目标4），确定差异表达基因的mRNA水平的顺式或反式控制（目标5）， 产生过表达10个候选基因的转基因小鼠，这些候选基因由Aims 3 -5的结果优先（Aim 6） 并鉴定可能影响肥胖的microRNA或其他转录的非编码基因（Aim 7）。长 最终结果是，我们将确定至少一个新的、强有力的、合理的肥胖基因。

Positional cloning - the identification of obesity genes by co-incidence of mapped obesity traits andgenes to a specific chromosomal region, provides a powerful method to discover novel obesity genes and to make novel insights into the mechanisms causing obesity. Mice have been used for the first identification of more human obesity genes than any other model. The goal of this proposal is to use positional cloning methods to identify obesity genes in mouse congenic strains. Congenic mouse strains are identical to a background strain except for a chromosomal region from a donor strain. Phenotype differences between congenic and background are due to alleles of the donor strain with functional effects different from the background strain. The two laboratories contributing to this proposal have identified several mouse congenic strains with statistically significant phenotypes for obesity on mouse chromosome 2 in a region homologous to human chromosome 20, where several obesity quantitative trait loci have been mapped. Our general hypothesis is that one or more genes or transcripts in the congenic donor regions influences obesity. Our specific working hypothesis is that genes/transcripts underlying obesity can be identified for most congenics. We propose seven Specific Aims. We will: determine diet, sex and age effects on obesity in the founding congenics (Aim 1), identify minimal chromosomal loci containing obesity genes by breeding congenics with ever smaller donor regions that retain obesity phenotypes (Aim 2), find differentially expressed donor region genes with whole genome microarrays using RNAfrom eight obesity tissues (Aim 3), sequence selected donor region genes (Aim 4), determine cis or trans control of mRNA levels for differentially expressed genes (Aim 5), produce transgenic mice overexpressing ten candidate genes prioritized by the results of Aims3-5 (Aim 6) and identify microRNAs or other transcribed non-coding genes that may influence obesity (Aim 7). The long term outcome is that we will identify at least one novel and strong and plausible obesity gene.