GENETICS OF DEVELOPMENTAL PLASTICITY IN THE ADIPOCYTE

描述（改编自研究者摘要）：这是一个新的RO 1 高级调查员申请5年支助， 鉴定控制白色脂肪中棕色脂肪细胞诱导的基因 组织.先前的工作，大部分是基于PI的开创性贡献， 表明解偶联蛋白1介导的棕色脂肪产热可以 对能量平衡有着重要的影响， 程序可以通过先前存在的棕色脂肪进行， 重要的是，通过在白色脂肪组织中产生新的棕色脂肪， 成年动物使用Ucp 1 mRNA水平作为棕色脂肪程度的标志物 腹膜后脂肪（通常为白色脂肪，因此不 表达Ucp 1），PI建议进一步表征和识别4或5 在初步的QTL和RI研究中已经鉴定的所谓的Iba基因 B6 vs. A/J小鼠。每个QTL定位在10 - 15 cM的范围内 间隔;在目标1中，Iba遗传结构将通过以下方式进行研究： 构建每个基因座的B6.A和A.B6同源系，然后测量 这些QTL自身及其在16个不同组合中的效应。为 当作为同源系单独检查时，其效应仍然稳健的QTL， 在目标2中将进行进一步的遗传杂交，以缩小区域; 此外，来自B6.CAST同源基因全基因组的相应菌株 将评价Iba表型，如果阳性，则与 B6与A/J交叉。在目标3中，将针对以下基因座生成BAC重叠群： 位置可缩小到1 - 2cM（PI表明染色体上的Iba 4 19符合这一标准），候选基因将通过直接测序鉴定。 测序并参考B6和A/J腹膜后脂肪cDNA文库， PI建议构建。同时（目标4），将进行SAGE分析 使用来自同源系的腹膜后脂肪RNA。最后（目标5）， 候选cDNA或基因将通过在细胞培养物中互补来测试 基于前脂肪细胞或使用B6.A同源基因的BAC转基因的系统。

DESCRIPTION (Adapted from investigator's abstract): This is a new RO1 application from a senior investigator that requests 5 years of support to identify genes that control the induction of brown adipocytes in white fat tissue. Prior work, much of it based on seminal contributions of the PI, indicates that brown fat thermogenesis mediated by Uncoupling protein 1 can have a significant impact on energy homeostasis, and that activation of this program can proceed through previously existing brown fat but also, importantly, by the development of new brown fat within white adipose tissue of adult animals. Using Ucp1 mRNA levels as a marker for the extent of brown fat induction in retroperitoneal fat (which is normally white fat and so does not express Ucp1), the PI proposes to further characterize and identify 4 or 5 so-called Iba genes that have been identified in preliminary QTL and RI studies of B6 vs. A/J mice. Each of the QTLs has been localized to a 10 - 15 cM interval; in Aim 1, Iba genetic architecture will be investigated by constructing B6.A and A.B6 congenic lines for each of the loci, then measuring the effect of those QTLs by themselves and in 16 different combinations. For QTLs whose effect remains robust when examined in isolation as a congenic line, further genetic crosses will be carried out in Aim 2 to narrow the region; in addition, corresponding strains from a genome-wide panel of B6.CAST congenics will be evaluated for the Iba phenotype and, if positive, used in parallel with the B6 vs. A/J cross. In Aim 3, BAC contigs will be generated for loci whose position can be narrowed to 1 - 2 cM (the PI suggests that Iba4 on chromosome 19 meets this criteria), and candidate genes will be identified by direct sequencing and reference to B6 and A/J retroperitoneal fat cDNA libraries the PI proposes to construct. In parallel (Aim 4), SAGE analysis will be undertaken using retroperitoneal fat RNA from the congenic lines. Finally (Aim 5), candidate cDNAs or genes will be tested by complementation in a cell culture system based on preadipocytes or BAC transgenesis using B6.A congenics.