MOLECULAR/ GENETIC BASIS OF EARLY CONOTRUNCAL MORPHOGENESIS

早期躯干形态发生的分子/遗传基础

• 批准号: 6302543
• 负责人: CLAYTON A BUCK
• 金额: $ 17.17万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2000-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6302543
• 关键词: chromosome deletion; congenital heart disorder; developmental genetics; early embryonic stage; gene deletion mutation; gene expression; gene targeting; genetic models; genetic screening; genetically modified animals; histogenesis; in situ hybridization; laboratory mouse; linkage mapping; phenotype; plasmids; yeast two hybrid system

(Adapted from the Applicant's Abstract) The microdeletion of 22q11.2 associated with over 90 percent of the cases of DiGeorge syndrome, referred to as the DiGeorge Critical Region (DGCR), is highly variable in size and does not predict severity of phenotype. Within the DGCR is a 200-250 kb segment common to all deleted patients designated the minimal DiGeorge Critical Region (MDGCR), suggesting that at least some genes relevant to the DGS phenotype reside in this region. To test this hypothesis, the investigators assembled a cosmid and BAC contig of mouse chromosome 16 and established a region of synteny with the MDGCR (Galili et al., 1997). This has been extended to include regions syntenic to most of the 2.5 Mb DGCR, and contains 25 or the 26 known genes within the human DGCR. Synteny between mouse and human DGCR is almost complete with respect to gene content, order and intron/exon composition, and includes six genes of potential importance to outflow tract morphogenesis. The approach to determining the role of these and other genes to outflow tract morphogenesis is based upon the hypothesis that: (1) the DiGeorge phenotype is the result of a change in copy number of one or more genes within the DGCR; (2) the critical morphogenetic event(s) may depend upon the coordinated expression of more than one gene; (3) the variable severity of DGS phenotypes is the result of changes in expression of different combinations of genes as well as variable genetic backgrounds; (4) within the MDGCR is at least one gene critical to some aspect of early heart morphogenesis. The goals are, therefore to evaluate the morphogenetic function of individual genes using reagents and sequence data generated over the past four years, use animals transgenic for overlapping BACs and cosmids to evaluate the morphogenetic role of multiple genes in the context of their "native" genetic environment within the DGCR, and explore the role of new genes the investigators have identified by representational difference analysis and with the yeast 2-hybrid system in early heart morphogenesis and subsequent role in congenital outflow tract abnormalities within "non-deleted" patients.

（改编自申请人的摘要）与超过90%的DiGeorge综合征病例相关的22q11.2的微缺失，称为DiGeorge临界区（DGCR），其大小变化很大，不能预测表型的严重程度。 在DGCR内是所有缺失患者共有的200-250 kb片段，称为最小DiGeorge关键区（MDGCR），表明至少一些与DGS表型相关的基因存在于该区域中。 为了检验这一假设，研究人员组装了小鼠16号染色体的粘粒和BAC重叠群，并建立了与MDGCR的同线性区域（Galili et al.，1997年）。 这已经扩展到包括与大多数2.5 Mb DGCR同线的区域，并且包含人DGCR内的25或26个已知基因。 小鼠和人类DGCR之间的同线性几乎是完整的基因内容，顺序和内含子/外显子组成，并包括6个基因的潜在重要性流出道形态发生。 确定这些和其它基因对流出道形态发生的作用的方法基于以下假设：（1）DiGeorge表型是DGCR内一个或多个基因拷贝数变化的结果;（2）关键形态发生事件可能取决于一个以上基因的协调表达;（3）DGS表型的不同严重程度是不同基因组合的表达变化以及不同遗传背景的结果;（4）MDGCR内至少有一个基因对早期心脏形态发生的某些方面至关重要。 因此，目标是使用过去四年中产生的试剂和序列数据来评估单个基因的形态发生功能，使用对于重叠BAC和cosmetry转基因的动物来评估多个基因在DGCR内的“天然”遗传环境的背景下的形态发生作用，并探索研究人员通过代表性差异分析和酵母2-杂合系统在早期心脏形态发生中作用及随后在“非缺失”患者先天性流出道异常中的作用