Functional Dissection of CNVs in Neurodevelopmental Traits

理解拷贝数变异(CNV)对人类病理学的贡献仍然具有挑战性，在 部分是因为它们内部的轨迹影响复杂而多样。在某些情况下，单次剂量敏感 轨迹驱动病理。在其他例子中，多个基因通过加性效应影响表型。 并通过复杂的遗传交互作用。在上一个资助期，我们专注于缺失综合症 和相互的CNV，并询问我们是否可以开发工具来帮助识别司机基因。 这项工作的进展为病理学的几个领域提供了信息。例如，将SIN3B标识为 导致复杂神经发育表型的19p13.1上非复发性230 kb缺失的驱动因素 增强Sin3/HDAC转录辅阻遏物复合体在神经发育中的作用并促进 表型复制CNV的孟德尔突变的鉴定。在17q24.2 CNV的案例中，我们了解到 关于人工合成的CNV表型，可能是由于BPTF和PSMD12的剂量不平衡造成的。最后， 对与16p11.2 CNV相关的多种表型的建模表明：(A)关键的神经发育 头面部病变从人类到小鼠、大鼠、斑马鱼都是保守的；(B) 基因座之间离散的上位性相互作用；和(C)产生了一系列替代模式生物，在这些模式生物中 进行途径分析和药物发现。总体而言，CNV的基因和功能解剖 样本强调了三个观察结果：(A)并不是CNV中的所有基因都是剂量敏感的(怀疑， 但现在得到了实验证据的支持)；(B)一些基因在一个方向上对剂量敏感(Gain， (C)非驱动基因可以参与不同的遗传相互作用。这些知识和知识 实验工具的获得为我们提供了扩大抱负的机会。我们仍然不明白为什么 CNV内联合剂量影响表型，以及从先前工作中吸取的教训是否 可以广泛地概括。此外，鉴于CNV对疾病负担的巨大贡献，至关重要的是 我们关注治疗途径的发展。我们提出了三个目标：(1)我们将剖析一个 一组独特的CNV，其中表型仅由复制来识别三重敏感基因和 问一问疾病易感性是否是由阈值效应驱动的，以此来理解为什么只有 人类基因的子集是剂量敏感的。(2)我们将利用现有的斑马鱼模型来表征 用16p11.2的神经元和面软骨表型研究上位性效应的分子特性 并询问我们是否能在转录调控水平上检测到上位性。(3)我们将把我们的 使用连通性地图(Cmap)Touchstone数据集的CNV司机斑马鱼模型的广泛曲目 以及一项新开发的安全性/有效性方案，以确定候选疗法。共同努力，我们的研究将 改进基因组疾病的遗传结构，告知遗传相互作用的分子基础，以及 绘制一条系统的治疗神经发育特征的路径。

Understanding the contribution of copy number variants (CNVs) to human pathology remains challenging, in part because of the complex and varied influence of loci within them. In some cases, a single dosage-sensitive locus drives pathology. In other examples, multiple genes contribute to phenotypes through additive effects and through complex genetic interactions. In the previous funding period, we focused on deletion syndromes and reciprocal CNVs and asked whether we could develop tools to aid the identification of driver genes. Progress in that work has informed several areas of pathology. For example, the identification of SIN3B as a driver of a non-recurrent 230 kb deletion on 19p13.1 that causes a complex neurodevelopmental phenotype reinforced the role of the Sin3/HDAC transcriptional corepressor complex in neurodevelopment and facilitated the identification of Mendelian mutations that phenocopy the CNV. In the case of the 17q24.2 CNV, we learned about the synthetic CNV phenotype likely caused by dosage imbalance of both BPTF and PSMD12. Finally, modeling of multiple phenotypes associated with the 16p11.2 CNV showed how: (a) key neurodevelopmental and craniofacial pathologies were conserved from humans, to mice, to rats, to zebrafish; (b) demonstrated discrete epistatic interactions between loci; and (c) generated a host of surrogate model organisms in which to perform both pathway analysis and drug discovery. Overall, the genetic and functional dissection of CNV exemplars has underscored three observations: (a) not all genes in a CNV are dosage sensitive (suspected, but now supported by experimental evidence); (b) some genes are dosage sensitive in one direction (gain, loss, but not both); and (c) non-driver genes can participate in distinct genetic interactions. The knowledge and experimental tools gained affords us the opportunity to expand our ambition. We still do not understand how intra-CNV combinatorial dosage influences phenotype, and whether the lessons learned from prior work are broadly generalizable. Moreover, given the non-trivial contribution of CNVs to disease burden, it is crucial that we pay attention to the development of therapeutic avenues. We propose three Aims: (1) We will dissect a unique set of CNVs, in which the phenotype is driven only by duplication to identify triplosensitive genes and ask whether disease susceptibility is driven by a threshold effect as a means to understanding why only a subset of human genes are dosage sensitive. (2) We will harness our existing zebrafish models to characterize the molecular properties of epistatic effects using the neuronal and facial cartilage phenotypes of the 16p11.2 CNV and ask whether we can detect epistasis at the level of transcriptional regulation. (3) We will combine our extensive repertoire of zebrafish models of CNV drivers with the Connectivity Map (CMap) Touchstone dataset and a newly developed safety/efficacy protocol to identify candidate therapeutics. Together, our studies will refine the genetic architecture of genomic disorders, inform the molecular basic of genetic interactions, and chart a systematic path toward therapeutics for neurodevelopmental traits.