Genetic Studies of Ocular Angiogenesis

描述(申请人提供)：血管生成，即新血管的形成，是一种严格调控的功能，由内源性血管生成刺激因子与抑制因子的局部平衡决定。这一建议的中心假设是，血管生成平衡在个体之间存在差异，这种差异在很大程度上是由基因决定的。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不同。我们调查了近亲交配的小鼠品系，看看小鼠是否具有模拟人类的一系列血管生成多样性。使用角膜微袋新生血管试验，我们观察到不同品系的小鼠对碱性成纤维细胞生长因子(BFGF)或血管内皮生长因子(VEGF)的反应性差异超过10倍。观察到的这些性状的遗传模式支持QTL(数量性状基因座)方法来定位导致血管生成反应差异的基因。为了克服分析中的变异性，我们使用了重组自交系来定位这种表型。在BXD(C57BL/6J x DBA/2J)小鼠中，我们绘制了负责调节VEGF和bFGF诱导的血管生成的区域。血管内皮生长因子的反应性与2号和10号染色体上的区域有关，而碱性成纤维细胞生长因子的反应性与4、13、15和18号染色体上的区域有关。我们现在建议通过测试同源和共生小鼠的表型来确认这些连锁区域，这些小鼠是为了将上述每个连锁的DBA/2J区域分离到C57BL/6J遗传背景上而培育的。我们还在绘制一组不同的重组近交系小鼠AXB(A/J x C57BL/6J)的表型图，以确定重叠的相关区域。接下来，我们将通过执行精细映射来优化我们的链接区域。最后，我们计划利用Celera小鼠SNP数据库在我们的最强关联区域中识别和筛选候选基因。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.