Development of Xenopus as a Model to Study Congenital Heart Disease

描述（由申请人提供）： 该提案的目的是大幅增加受保护的研究时间，以提高目前资助的R 01（及其待更新）的生产力，同时使候选人能够成功竞争第二个主要资助（即新的R 01或计划资助项目）。候选人在两所相距约120英里的州立大学之间担任联合教职。旅行，教学和服务义务留下45%的时间用于研究。K 02奖的支持将使候选人从大多数教学和服务任务中解脱出来，在未来五年内产生80-95%的时间专门用于研究。候选人资助的R 01和待更新的总体目标是发现心脏发育的基本机制，并确定它们在心脏（dys）形态发生期间如何受到偏侧基因的影响。为了实现这一目标，候选人在青蛙非洲爪蟾的胚胎中建立了实验诱导的异位模型。异位胚胎表现出异常的心脏和内脏器官L-R不对称，伴有复杂的先天性心脏缺陷（CHD）。使用创新的细胞标记策略来产生脊椎动物心脏的第一个L-R细胞谱系图，候选人发现L-R细胞谱系组成在异位心脏中是异常的，并且L-R谱系缺陷与结构性CHD共定位。基于这些结果和其他结果，K 02的目的是在非洲爪蟾中鉴定心脏细胞群，这些细胞群与来自初级心脏野的工作心肌细胞一起构建心脏：次级心脏野、心脏神经嵴和心脏传导系统。这些目标将通过在领先的实验室中花费“微型手术”来实现，以适应在非洲爪蟾中使用的功能性技术（激光辅助组织消融、超声心动图、光学激活标测）和额外的胚胎学技术（笼状荧光葡聚糖、组织移植）。这将通过课程作业和参加专业会议来补充。来自K 02目标的数据将用于提出和检验关于各种心脏细胞群中L-R谱系组成在心脏（dys）形态发生中所起作用的新假设。这项工作的意义将是阐明心脏发育的保守机制，这反过来将确定基因和诱导过程，如果受到遗传或环境扰动的影响，可能会导致心脏病。 (End摘要）

DESCRIPTION (provided by applicant): The objective of this proposal is to substantially increase protected research time in order to boost productivity on a currently funded R01 (and its pending renewal) while positioning the candidate to successfully compete for a second major grant (i.e. a new R01 or a project on a programmatic grant). The candidate holds a joint faculty position between two state universities located ~120 miles apart. Travel, teaching and service obligations leave 45% time available for research. Support by a K02 award would release the candidate from most teaching and service assignments, generating 80-95% time over the next five years to be spent exclusively on research. The overall objectives of the candidate's funded R01 and pending renewal are to discover fundamental mechanisms of heart development, and to determine how they are affected by laterality genes during cardiac (dys)morphogenesis. To achieve this, the candidate has established an experimentally-induced heterotaxy model in embryos of the frog, Xenopus laevis. The heterotaxy embryos exhibit abnormal cardiac and visceral organ L-R asymmetries that are accompanied by complex, congenital heart defects (CHDs). Using an innovative cell labeling strategy to produce the first L-R cell lineage map of the vertebrate heart, the candidate discovered that L-R cell lineage composition is anomalous in heterotaxy hearts, and that the L-R lineage defects co-localize with structural CHDs. Based on these results and others, the K02 Aims are to identify in Xenopus the cardiac cell populations that, together with working cardiomyocytes derived from the primary heart fields, build the heart: secondary heart field, cardiac neural crest, and cardiac conduction system. These Aims will be accomplished by spending "minisabbaticals" in leading labs to adapt functional (laser-assisted tissue ablation, echocardiography, optical activation mapping) and additional embryological techniques (caged fluorescent dextrans, tissue grafting) for use in Xenopus. This will be complemented by coursework and participation in professional meetings. Data from the K02 Aims will be used to propose and test novel hypotheses on the role that L-R lineage composition in various cardiac cell populations play in cardiac (dys)morphogenesis. The significance of this work will be to elucidate conserved mechanisms of heart development, which in turn, will identify genes and inductive processes that may cause CHDs if affected by genetic or environmental perturbations. (End of Abstract)