GENETIC ANALYSIS OF EARLY LIMB DEVELOPMENT

早期肢体发育的遗传分析

• 批准号: 6685915
• 负责人: AREND SIDOW
• 金额: $ 22.6万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6685915
• 关键词: alleles; biological signal transduction; computer data analysis; developmental genetics; early embryonic stage; electroporation; gene expression; gene mutation; genetic polymorphism; laboratory mouse; limbs; mammalian embryology; molecular cloning; northern blottings; nucleic acid hybridization; nucleic acid sequence; polymerase chain reaction; regulatory gene; southern blotting; tissue /cell culture; western blottings

This project is part of a research program that seeks to understand molecular mechanisms of normal and abnormal limb pattern formation through the characterization of novel genes defined by mutations and polymorphisms in the mouse. Outgrowth and proximodistal patterning of the vertebrate embryonic limb require signaling by the apical ectodermal ridge (AER) to the progress zone (PZ), which proliferates in response and lays down the cells of the presumptive limb in a proximal to distal progression. The signaling loop between AER and PZ that is essential for sustaining outgrowth and patterning in the limb is disrupted in the antimorphic mouse mutation Dactylaplasia (Dac). Dac was cloned by position and found to encode a pioneer gene whose sequence reveals nothing about its function. The suppressor allele of a strain polymorphism, Modifier of Dactylaplasia (Mdac), has no phenotype on its own but dominantly suppresses Dac with 100 percent penetrance. The proposed research has three aims: (1) to understand the developmental function of the Dac gene by (a) generating and characterizing a targeted null allele and (b) determining the mechanism by which the two spontaneous mutations Dac1J and Dac2J exert their dominant effect; (2) to generate reagents (antibodies and a full length cDNA) that will allow future characterization of the biochemical and cell biological functions of the Dac gene; and (3) to clone Mdac by position. The experiments are designed to use the Dac/Mdac system as a novel entry point to investigate epithelial-mesenchymal interactions in growth and developmental patterning. Because Dac is likely to be the mouse ortholog of the human Split Hand/Foot Malformation 3 gene, this project may also bear direct relevance to understanding and diagnosis of congenital limb diseases.

该项目是一个研究计划的一部分，旨在通过小鼠突变和多态性定义的新基因的表征来了解正常和异常肢体模式形成的分子机制。 脊椎动物胚胎肢体的生长和近远端模式需要顶端外胚层脊（AER）向进展区（PZ）发出信号，进展区响应增殖并在近端到远端进展中放置假定肢体的细胞。 AER 和 PZ 之间的信号环路对于维持肢体的生长和模式至关重要，但在反形态小鼠突变指趾发育不良 (Dac) 中被破坏。 Dac 按位置克隆，发现其编码先锋基因，该基因的序列并未揭示其功能。 菌株多态性的抑制等位基因 Modifier of Dactylaplasia (Mdac) 本身没有表型，但显性抑制 Dac，外显率达 100%。拟议的研究有三个目标：（1）通过（a）生成和表征目标无效等位基因以及（b）确定两种自发突变 Dac1J 和 Dac2J 发挥显性效应的机制来了解 Dac 基因的发育功能； (2) 生成试剂（抗体和全长 cDNA），以便将来表征 Dac 基因的生化和细胞生物学功能； (3)按位置克隆Mdac。 这些实验旨在使用 Dac/Mdac 系统作为研究生长和发育模式中上皮间质相互作用的新切入点。 由于 Dac 很可能是人类手足畸形 3 基因的小鼠直系同源物，因此该项目也可能与先天性肢体疾病的理解和诊断直接相关。