GLUCOCORTICOSTEROID RECEPTOR AND CLEFT PALATE IN MICE

众所周知，小鼠品系对病毒的敏感性不同 皮质类固醇诱发的腭裂。它还表明，这一点 皮质类固醇(CORT)反应性的变化与遗传有关 主要组织相容性复合体(MHC， H-2在小鼠体内)。我们已经证明了H-2单倍型差异是 足以改变皮质醇诱导的对腭裂的易感性 正常长成熟时的时间变化。我们的新数据显示 CORT中这些单倍型特异性差异的机制 反应性很可能与调节表达的因素有关 糖皮质激素受体(GR)，它编码在H-2外 基因组区域。我们已经使用 很好地描述了H-2同源小鼠模型和免疫化学， 生物化学和分子方法来检验H-2病毒的假说 GR表达和/或功能的相关调节是关键 调节皮质醇反应性的分子机制，因此，皮质醇- 诱发性腭裂。目标1.GR翻译和翻译后 规则：分析特定单倍型的定性和定量 GR特征和原位空间格局的变异 在H-2同源基因小鼠中的分布和渐进性发展。目标 2.GR转录调控：比较单倍型特异性 在稳定状态水平、发育表达和 H-2同源基因GR mRNA的时空原位定位 具有渐进发展的菌株。目标3.GR功能分析： 阐明H-2相关GR功能差异的机制 通过比较H-2同源基因小鼠中单倍型特异性变异 (A)配体-GR与特定的高亲和力GRE DNA(GR-GRE)结合 结合)，以及(B)四个基因的表达和空间分布 发育表达的“皮质醇反应”基因(EGF、转化生长因子-β1、转化生长因子-β1、转化生长因子-β1) β_2、转化生长因子-β_3)。演示 GR表达和皮质醇反应的单倍型特异性变异- 活性将支持H-2复合体包含 编码调节GR的反式作用因子的遗传信息 表达式和/或功能。然后我们将继续进行基因图谱和 鉴定糖皮质激素反应性基因的克隆研究 小鼠17号染色体H-2复合体上或附近的基因座(GRG)， 随后，人类同源基因。

It is known that mouse strains differ in their susceptibility to corticosteroid-induced cleft palate. It has also been shown that this variation in corticosteroid (CORT) responsiveness is related to genetic variation in loci at or near the major histocompatibility complex (MHC, H-2 in mice). We have demonstrated that H-2 haplotype differences are sufficient to alter CORT-induced susceptibility to cleft palate and temporal changes in normal long maturation. Our new data indicates that the mechanism for these haplotype-specific differences in CORT responsiveness is likely related to factors modulating the expression of the glucocorticoid receptor (GR), which is encoded outside the H-2 genomic region. We have designed a series of Specific Aims using the well characterized H-2 congenic mouse model and immunochemical, biochemical and molecular methodologies to test the hypothesis that H-2 associated modulation of GR expression and/or function is a key molecular mechanism regulating CORT responsiveness and, hence, CORT- induced cleft palate. Aim 1. GR translational and post-translational regulation: to analyze haplotype-specific qualitative and quantitative variation in GR characteristics and pattern of in situ spatial distribution with progressive development among H-2 congenic mice. Aim 2. GR transcriptional regulation: to compare haplotype-specific differences in the steady state levels, developmental expression, and in situ spatiotemporal localization of GR mRNA among H-2 congenic strains with progressive development. Aim 3. GR function analysis: to delineate the mechanism of H-2 associated differences in GR function among H-2 congenic mice by comparing haplotype-specific variation in (a) ligand-GR binding to a specific high affinity GRE DNA (GR-GRE binding), and (b) mRNA expression and spatial distribution of four developmentally expressed "CORT-responsive" genes (EGF, TGF-beta1, TGF- beta2, TGF-beta3) in the presence of exogenous CORT. The demonstration of haplotype-specific variation in GR expression and CORT respons- iveness will support the hypothesis that the H-2 complex contains genetic information encoding trans-acting factors which regulate GR expression and/or function. We will then pursue gene mapping and cloning studies to identify the glucocorticoid responsiveness gene locus (GRG) at or near the H-2 complex on mouse chromosome 17, subsequently human homologs.