The role of continuous phenotypic variation in structural defects of the face

总结 尽管临床基因组学取得了巨大进展，但近一半的遗传病儿童从未接受过治疗。 诊断.原因之一是患者最初是根据症状和身体表现来诊断的 但对于许多遗传性疾病，即使是相同的患者，这些症状也会有很大的不同。 突变当具有相同突变的患者具有不同的表型时，这也意味着 治疗和预后，即使分子诊断是安全的。我们研究的长期目标是 该计划是为了了解如何基因型是翻译为变异表型使用各种模型 系统.在我们之前的资助周期中，我们使用了成纤维细胞生长因子8（Fgf 8）小鼠的等位基因系列， 显示Fgf 8基因表达水平和下游信号传导因子与细胞凋亡呈非线性相关。 表型。表型几乎没有变化，直到与野生型相比Fgf 8下降到50%以下，然后 低于该水平，Fgf 8的小变化产生平均表型及其方差的大变化。的 我们的下一步研究将推进这一概念，并有助于对 可变带宽和鲁棒性。具体来说，我们提出了两个概念上相关的目标， 在理解突变如何扰乱发展的核心问题， 不同的表型结果。在具体的目标1中，我们测试了基因相互作用的机制， 通路产生可变的表达率和表达率。我们之前的研究已经确定了上位性 这些相互作用可能调节FGF 8，在这个目标中，我们直接测试这些相互作用。在具体目标2中， 测试影响特定但普遍存在的过程的突变如何产生多模态范围的 表型。这一点很重要，因为遗传性疾病往往涉及到对运作机制的破坏， 在不同的组织和许多点的发展，但导致高度特异性的出生缺陷，如 前脑无裂或唇腭裂。作为这种普遍现象的模型，我们研究了 一氧化氮合酶相互作用蛋白（Nosip）在小鼠中的无效突变。NOSIP是一种E3-单泛素 修饰具有不同发育作用的靶蛋白活性的连接酶。在这两个目标中，我们采用了 高度创新的成像、形态测定、转录组学和实验方法的组合， 整合多个层次的输入（遗传，分子，细胞），以了解突变的影响 从基因表达水平到细胞动力学水平的级联影响有机体的形式。

Summary Despite tremendous progress in clinical genomics, nearly half of children with genetic disease never receive a diagnosis. One reason is that patients are initially diagnosed based on symptoms and physical manifestations but for many genetic conditions, those symptoms can vary dramatically even for patients with the same mutation. When patients with the same mutation have different phenotypes, that also has implications for treatment and prognosis, even when a molecular diagnosis is secured. The long-term goal of our research program is to understand how genotype is translated to variation in phenotype using a variety of model systems. In our previous funding cycle, we used an allelic series of Fibroblast growth factor 8 (Fgf8) mice and showed that levels of Fgf8 gene expression and downstream signalling factors were non-linearly related to the phenotype. Little change in phenotype occurs until Fgf8 drops below 50% compared to the wildtype, and then below that level small changes in Fgf8 produce large changes in the mean phenotype and its variance. The next step in our research advances this concept and helps generate a more mechanistic understanding of variable penetrance and robustness. Specifically, we propose two conceptually related aims that address distinct concepts in understanding the central question of how mutations perturb development to generate varied phenotypic outcomes. In specific Aim 1, we test mechanisms by which gene interactions within a pathway generate variable penetrance and expressivity. Our previous research has identified epistatic interactions that may modulate FGF8, and in this Aim, we test these interactions directly. In Specific Aim 2, we test how a mutation that affects a specific but ubiquitous process generates a multi-modal range of phenotypes. This is important because genetic diseases often involve disruptions to mechanisms that operate across diverse tissues and at many points in development and yet result in highly specific birth defects such as holoprosencephaly or cleft lip and palate. As a model for this general phenomenon, we investigate the effects of a null mutation in Nitric Oxide Synthase Interacting Protein (Nosip) in mice. NOSIP is an E3-monoubiquitin ligase that modifies activity of target proteins with diverse developmental roles. In both aims, we employ a highly innovative combination of imaging, morphometric, transcriptomic and experimental approaches to integrate multiple levels of input (genetic, molecular, cellular) to understand how the effects of a mutation cascade across levels from gene expression to cellular dynamics to influence organismal form.