Genetic Studies of Ocular Angiogenesis

描述（由申请人提供）：血管生成，即新血管的形成，是一种受到严格调控的功能，由内源性血管生成刺激剂与抑制剂的局部平衡决定。该提议的中心假设是，血管生成平衡在个体之间是不同的，这种差异在很大程度上是由遗传决定的。事实上，流行病学数据表明，不同种族的人群对眼部新生血管的易感性各不相同。我们调查了近亲繁殖的小鼠品系，看看小鼠是否具有模仿人类血管生成多样性的范围。通过角膜微袋新生血管实验，我们观察到不同小鼠品系对碱性成纤维细胞生长因子（bFGF）或血管内皮生长因子（VEGF）的反应性差异大于10倍。观察到的这些性状的遗传模式支持QTL（数量性状位点）方法来定位导致血管生成反应性差异的基因。为了克服试验中的变异性，我们使用重组自交系来绘制这种表型。在BXD （C57BL/6J x DBA/2J）小鼠中，我们绘制了负责调节VEGF和bFGF诱导血管生成的区域。VEGF反应性与2号和10号染色体上的区域有关，而bFGF反应性与4、13、15和18号染色体上的区域有关。我们现在建议通过检测基因型和经济型小鼠的表型来确认这些连锁区域，这些小鼠已被培育分离出上述连接的DBA/2J区域到C57BL/6J遗传背景上。我们还绘制了另一组被称为AXB （a /J x C57BL/6J）的重组近交系小鼠的表型图，以确认重叠的相关区域。接下来，我们将通过执行精细映射来细化链接区域。最后，我们计划利用Celera小鼠SNP数据库识别和筛选我们最强连接区域的候选基因。然后，候选基因将通过各种方法进行验证。

DESCRIPTION (provided by applicant): Angiogenesis, the formation of new blood vessels, is a tightly regulated function determined by the local balance of endogenous angiogenesis stimulators versus inhibitors. The central hypothesis for this proposal is that the angiogenic balance varies between individuals and that this variation is in large part genetically determined. Indeed, epidemiological data suggests that different racial populations have varied susceptibility to ocular neovascularization. We have surveyed inbred mouse strains to see if mice have a range of angiogenic diversity that models that of humans. Using the corneal micro pocket neovascularization assay, we have observed a greater than ten-fold difference in responsiveness to either basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) among various mouse strains. The inheritance pattern observed for these traits supported a QTL (quantitative trait locus) approach to mapping the genes responsible for the differences in angiogenic responsiveness. To overcome variability in the assay, we used recombinant inbred lines to map this phenotype. In BXD (C57BL/6J x DBA/2J) mice, we have mapped the regions responsible for regulating VEGF and bFGF induced angiogenesis. VEGF responsiveness is associated with regions on chromosomes 2 and 10, while bFGF responsiveness is associated with regions on chromosomes 4, 13, 15 and 18. We now propose to confirm these areas of linkage by testing the phenotype in congenic and consomic mice that have been bred to isolate each of the above linked DBA/2J areas onto a C57BL/6J genetic background. We are also mapping the phenotype in a different set of recombinant inbred mice known as AXB (A/J x C57BL/6J) to confirm overlapping associated areas. Next we will refine our linked regions by performing fine mapping. Lastly, we plan to identify and screen candidate genes in our strongest linked regions by utilizing the Celera mouse SNP database. Candidate genes will then be validated by a variety of methods.