In vivo reagents to identify functional noncoding sequences in the TCF7L2 locus

描述（由申请人提供）：最近的一份报告表明，TCF7L2基因的遗传变异与3个人群中发生2型糖尿病的风险相关。此后，有几篇报道重复并有力地验证了这些最初的观察结果，使得寻找TCF7L2调节葡萄糖稳态的因果序列变化和机制成为糖尿病研究的重点。然而，这些报告也表明，因果变异在本质上可能是非蛋白质编码的，可能包含在包括TCF7L2内含子3和4在内的92 kb的连锁不平衡块中，这使得鉴定致病序列变异非常困难。在本应用中，我们提出验证TCF7L2的内含子3和4包含负责该基因组织特异性表达模式的进化保守的顺式调控元件的假设。我们将结合生物信息学工具和体内小鼠转基因报告分析技术来表征内含子3和4中进化保守的非编码序列，并确定TCF7L2可能具有功能性非编码变异的顺式调控元件，从而导致糖尿病风险。这些研究将确定可能包含与人类糖尿病相关的致病变异的功能性非编码序列，并将产生关键的分子和体内试剂，可用于设计和测试将TCF7L2生物学与患糖尿病风险联系起来的假设。一些研究表明，TCF7L2基因的DNA序列变异可能是导致2型糖尿病风险的重要因素。然而，DNA序列的改变可能是在控制基因何时何地被激活的调控元件中。我们提出了一个合理的策略来识别这些监管要素。

DESCRIPTION (provided by applicant): A recent report suggested that genetic variations within the TCF7L2 gene are associated with risk to develop type 2 diabetes in 3 populations. Several reports have since replicated and strongly validated these initial observations, making the search for the causal sequence variations and the mechanisms whereby TCF7L2 modulate glucose homeostasis a priority in diabetes research. Nevertheless, these reports also indicate that the causal variation is likely to be non-protein coding in nature, likely contained within a linkage disequilibrium block of 92 kb that includes introns 3 and 4 of TCF7L2, making the identification of the causative sequence variants extremely difficult. In this application, we propose to test the hypothesis that introns 3 and 4 of TCF7L2 harbor evolutionarily conserved cis-regulatory elements responsible for the tissue-specific expression patterns of this gene. We will use a combination of bioinformatic tools and in vivo mouse transgenic report assay technologies to characterize the evolutionarily conserved noncoding sequences within introns 3 and 4, and identify TCF7L2 the cis-regulatory elements that may harbor functional noncoding variation conferring risk to diabetes. These studies will identify the functional noncoding sequences that may harbor the causative variations associated with diabetes in humans and will generate critical molecular and in vivo reagents that can be used to design and test hypotheses that connect TCF7L2 biology to the risk of developing diabetes. Several studies indicate that DNA sequence variation in the TCF7L2 gene may be an important factor conferring risk to develop type 2 diabetes. Nevertheless, the DNA sequence changes are probably in regulatory elements that control where and when this gene is activated. We propose a rational strategy to identify these regulatory elements.