Genetic Studies of Ocular Angiogenesis

描述（由申请人提供）：血管生成，即新血管的形成，是一种由内源性血管生成刺激剂与抑制剂的局部平衡决定的严格调节的功能。这个提议的中心假设是，血管生成平衡在个体之间变化，并且这种变化在很大程度上是由遗传决定的。事实上，流行病学数据表明，不同种族人群对眼部新生血管的易感性不同。我们已经调查了近交系小鼠品系，以了解小鼠是否具有一系列模拟人类的血管生成多样性。使用角膜微囊新生血管形成试验，我们已经观察到不同小鼠品系之间对碱性成纤维细胞生长因子（bFGF）或血管内皮生长因子（VEGF）的反应性存在10倍以上的差异。观察到的这些性状的遗传模式支持QTL（数量性状位点）的方法来定位的基因负责血管生成反应的差异。为了克服测定中的变异性，我们使用重组近交系来绘制该表型。在BXD（C57 BL/6 J x DBA/2 J）小鼠中，我们绘制了负责调节VEGF和bFGF诱导的血管生成的区域。VEGF反应性与染色体2和10上的区域相关，而bFGF反应性与染色体4、13、15和18上的区域相关。我们现在建议确认这些领域的联系，通过测试表型在同类和consomic小鼠，已被饲养隔离到C57 BL/6 J遗传背景上的上述连锁DBA/2 J地区。我们还绘制了另一组重组近交系小鼠AXB（A/J x C57 BL/6 J）的表型，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的区域。最后，我们计划通过利用Celera小鼠SNP数据库来识别和筛选我们最强连锁区域中的候选基因。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.