Seq-ing the etiology of birth defects in a new frog model, Lepidobatrachus laevis

测序新青蛙模型 Lepidobtrachus laevis 中出生缺陷的病因

• 批准号: 8771976
• 负责人: Nanette M Nascone-Yoder
• 金额: $ 22.73万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8771976
• 关键词: Amphibia; Anatomy; Animal Model; Biocompatible Materials; Biological; Biological Assay; Biological Markers; Caliber; Candidate Disease Gene; Cell physiology; Child; Clinical; Complex; Congenital Abnormality; Contralateral; Defect; Deformity; Development; Developmental Biology; Developmental Process; Disease; Embryo; Embryonic Development; Embryonic Heart; Etiology; Event; Excision; Fertilization; Gastrointestinal tract structure; Gene Expression; Gene Expression Profile; Genomics; Goals; Handedness; Heart; Homologous Gene; Hour; Human; Human Biology; Individual; Infant; Infant Mortality; Knowledge; Laboratories; Larva; Lead; Left; Life; Mammals; Measures; Methodology; Modeling; Molecular; Morbidity - disease rate; Morphogenesis; Oocytes; Organ; Organism; Organogenesis; Phase; Rana; Reagent; Research; Resolution; Resources; Risk; Shapes; Side; South American; Staging; Structural Congenital Anomalies; Tadpoles; Testing; Therapeutic Intervention; Tissues; Transcript; Tube; United States; Work; Xenopus oocyte; animal model development; blastocyst; body system; genetic variant; genome-wide; human disease; in vivo; innovation; malformation; mortality; novel; patient population; public health relevance; response; transcriptome sequencing

DESCRIPTION (provided by applicant): The causes of most human birth defects are unknown. Structural defects in the heart and digestive tract are frequently found in association with abnormal left-right asymmetries in other organ systems, suggesting that such deformities may result from perturbed laterality, yet the developmental processes that form asymmetries within individual organs remain elusive. The long term goal is to determine the morphogenetic mechanisms that control the development of anatomical left-right asymmetry. The objective of this exploratory R21 application is to gain a comprehensive view of the left-right asymmetric molecular differences within the embryonic heart and gut tubes as they undergo asymmetric "looping", a fundamental organogenesis event that orients the most crucial anatomical asymmetries. To accomplish this objective, the unique embryological features of a novel model amphibian, Lepidobatrachus laevis, will be developed and exploited. Lepidobatrachus has massive embryos that facilitate precise excision of the left and right halves of the early heart an gut during looping, enabling the heretofore infeasible approach of left-right transcriptome profiling during a key phase of asymmetric morphogenesis. The central hypothesis is that identifying transcripts that are differentially expressed between the contralateral halves of looping organs will identify new molecules that control left-right asymmetric morphogenesis. This hypothesis will be tested via two specific aims: 1) Identify transcripts that are differentialy expressed between the left and right sides of the looping heart and gut tubes; and 2) Validate the biological relevance of left- or right-enriched transcripts for asymmetric organ morphogenesis. Under Aim 1, an RNAseq approach (supported by a draft Lepidobatrachus transcriptome already constructed by the PI) will be used to complete genome-wide expression analyses that will reveal unilaterally-enriched transcripts associated with the formation of key anatomical asymmetries. Under Aim 2, the proven ability to precisely target exogenous reagents to the left or right side of developing organs in amphibians, and the unprecedented subcellular resolution of developing organ asymmetries provided by the sizeable Lepidobatrachus, will be used to authenticate the in vivo function of select unilaterally-enriched transcripts in asymmetric morphogenesis. The approach is innovative because it takes advantage of the distinctive attributes of a unique non-model organism to understand one of the key unanswered questions in the field of left-right development: what are the mechanism(s) by which developing organs acquire critical left- right asymmetric anatomical features? The proposed research is significant because it is expected to immediately accelerate our understanding of the etiology of some of the most common birth defects by identifying new classes of molecules, and new cellular processes, which shape the fundamental left-right asymmetry of the heart and gut.

描述（由申请人提供）：大多数人类出生缺陷的原因尚不清楚。心脏和消化道中的结构缺陷经常与其他器官系统中的左右不对称异常相关，这表明这种畸形可能是由于横向扰动而导致的，但是在单个器官中形成不对称的发育过程仍然难以捉摸。长期目标是确定控制解剖左右不对称发展的形态发生机制。这种探索性R21应用的目的是在胚胎心脏和肠管内的左右不对称分子差异中获得全面的看法，因为它们经历了不对称的“循环”，这是一种基本的器官发生，这是最关键的解剖学不对称的。为了实现这一目标，将开发和开发新型模型两栖动物Lepidobatrachus laevis的独特胚胎学特征。鳞翅目具有巨大的胚胎，可在循环过程中精确切除早期心脏的左和右半部分，这使得迄今为止在不对称形态发生的关键阶段左右转录组分析的方法是不可行的方法。中心假设是，识别循环器官对侧两半之间差异表达的转录本将识别控制左右不对称形态发生的新分子。该假设将通过两个特定目的进行检验：1）识别循环心脏和肠管左侧和右侧之间差异表达的转录本； 2）验证左或右添加的转录物的生物学相关性，以形态发生。在AIM 1下，将使用RNASEQ方法（由PI已构建的Lepidobatrachus转录组草案支撑）将用于完成全基因组全基因组表达分析，该分析将揭示与关键解剖学不对称的形成相关的单方面增强的转录本。在AIM 2下，在两栖动物中开发器官的左侧或右侧精确靶向外源试剂的经验证明的能力，以及由较大的鳞翅目提供的前所未有的细胞内部分辨率，可用于将其无体性地分配的无体性替代品的无性化功能来构成。 形态发生。这种方法具有创新性，因为它利用了独特的非模型生物的独特属性来理解左右发展领域的关键未解决的问题之一：开发器官通过哪些机制获得了关键的左右 - 右 - 右非对称性解剖学特征？拟议的研究之所以重要，是因为预计它将通过鉴定新的分子和新的细胞过程来立即加速我们对某些最常见的先天缺陷的病因的理解，这些过程塑造了心脏和肠道的基本左右不对称。