Mapping adiposity genes in mice

在小鼠中，许多基因组区域包含导致肥胖差异的变异。 (Reed 2003；2006；2007；2008)。这项研究计划的目标是找到基因或 小鼠9号染色体上数量性状基因座Adip5的基因 与性腺脂肪库的重量增加有关。尽管有几个 一系列证据表明，这里的一个基因或基因变体有能力调节 肥胖症，导致这种影响的确切基因或DNA序列尚不清楚。这个 QTL Adip5的特性使其成为位置克隆方法的实用靶标： 它不是特别容易受到母性效应或上位性交互作用的影响，而且它是 与不同的表型(性腺库重)相关。此外， 实验计划被设计为在基因座被印记的情况下识别ADIP5(即，如果有 原籍父母效应)。在当前的ADIp5可信区间内，有几个 可信的候选基因(Bbs4、Cpy19a1、Crabp1、Cplx3、Il18、Lipc、Nedd4)以及 数十个基因和功能未知的非编码RNA。使用9号染色体 为此目的，我们实验室开发了替代菌株(css-9)，我们将 将这些小鼠回交到宿主菌株(C57BL/6ByJ；B6)并进行基因组扫描 降低ADIp5的可信区间(css-9XB6n2基因组扫描；目标1)。基座 在遗传图谱信息提供的精细化置信度区间上，我们将 在连续的繁殖周期中，将该染色体解析成小的间隔，并 创建微基因菌株(&lt；200kb)，其中一个将包含相关基因 对于ADIP5(目标2)。为了确定导致ADIp5的确切基因，我们将从基因上 将一个或多个含有129个DNA片段的小鼠品系改造成B6 背景通过同源重组，并评价其对性腺库的影响 重量(具体目标3)。这项工作的长期目标是开发一种方法来 系统地识别导致小鼠肥胖正常变化的基因。

In mice, many genomic regions contain variation that results in differences in adiposity (Reed 2003; 2006; 2007; 2008). The goal of this research program is to find the gene or genes on mouse chromosome 9 that account for the quantitative trait locus Adip5, which is associated with increased weight of the gonadal adipose depot. Although several lines of evidence suggest that a gene or genetic variant here has the ability to regulate adiposity, the exact gene or DNA sequence that causes this effect is not known. The QTL Adip5 has features that make it a practical target for a positional cloning approach: it is not particularly susceptible to maternal effects or epistatic interactions, and it is associated with a distinct phenotype (gonadal depot weight). Furthermore, the experimental plan is designed to identify Adip5 if the locus is imprinted (i.e., if there are parent-of-origin effects). Within the current Adip5 confidence interval, there are several credible candidate genes (Bbs4, Cpy19a1, Crabp1, Cplx3, Il18, Lipc, Nedd4), as well as dozens of genes and noncoding RNA of unknown function. Using a chromosome 9 substitution strain developed in our laboratory for this purpose (CSS-9), we will backcross these mice to the host strain (C57BL/6ByJ; B6) and conduct a genome scan to reduce the confidence interval of Adip5 (CSS-9 X B6 N2 genome scan; Aim 1). Based on the refined confidence interval provided by the genetic mapping information, we will parse this chromosome into small intervals through successive breeding cycles, and create microcongenic strains (<200 kb), one of which will contain the gene responsible for Adip5 (Aim 2). To identify the exact gene responsible for Adip5, we will genetically engineer one or more mouse strains with a segment of 129 DNA substituted into a B6 background by homologous recombination, and evaluate its effect on gonadal depot weight (Specific Aim 3). The long-range goal of this work is to develop an approach to systematically identify genes that contribute to normal variation in fatness among mice.