GENETICS OF DEVELOPMENTAL PLASTICITY IN THE ADIPOCYTE

描述(改编自调查人员摘要)：这是一只新的RO1 高级调查员的申请，要求提供5年的支持 识别控制白色脂肪中棕色脂肪细胞诱导的基因 组织。之前的工作，其中大部分是基于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 对能量动态平衡有重大影响，并激活这一点 程序可以通过先前存在的棕色脂肪进行，但也 重要的是，通过白色脂肪组织中新的棕色脂肪的发展 成年动物。用Ucp1mRNA水平作为棕色脂肪程度的标志 诱导腹膜后脂肪(通常是白色脂肪，因此不是 快递Ucp1)，PI建议进一步描述和确定4或5 已在QTL和RI初步研究中确定的所谓Iba基因 B6小鼠与A/J小鼠。每个QTL都定位在10-15 cM 在目标1中，iba遗传结构将由 构建每个座位的B6.A和A.B6同源系，然后测量 这些QTL本身以及在16个不同组合中的效应。为 QTL作为同源品系单独检测时，其效应仍然很强， 将在目标2进行进一步的遗传杂交，以缩小区域范围； 此外，来自全基因组B6CAST同源基因小组的相应菌株 将对iba表型进行评估，如果呈阳性，则与 B6对A/J交叉。在目标3中，将为其基因座生成BAC重叠群 位置可以缩小到1-2 cM(PI表明染色体上的Iba4 19个符合这一标准)，候选基因将通过直接 B6和A/J腹膜后脂肪文库的测序及参考 派提议建造。同时(目标4)，将进行SAGE分析 使用来自同源品系的腹膜后脂肪RNA。最后(目标5)， 候选的cDNA或基因将通过细胞培养中的互补进行测试。 基于前脂肪细胞的系统或使用B6.A基因的BAC转基因。

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.