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，该计划试图通过表征由小鼠中突变和多态性定义的新基因来理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产物和近端模式需要顶端外皮脊（AER）信号传导到进度区（PZ），这在距离近端到远端的进展中增殖并散布在响应中，并降低了假定肢体的细胞。 AER和PZ之间的信号回路对于维持肢体中的出生和模式至关重要，在抗鲜艳的小鼠突变dactylaplasia（DAC）中被破坏。 DAC通过位置克隆，发现编码一个先锋基因，其序列没有揭示其功能。 菌株多态性的抑制等位基因，Dactylaplasia（MDAC）的修饰剂（MDAC）本身没有表型，但主要抑制了DAC，以100％的渗透率抑制了DAC。拟议的研究具有三个目的：（1）通过（a）产生和表征靶向无效等位基因的DAC基因的发育功能，以及（b）确定两个自发突变DAC1J和DAC2J发挥其主导作用的机制； （2）生成试剂（抗体和全长cDNA），以使DAC基因的生化和细胞生物学功能的未来表征； （3）按位置克隆MDAC。 该实验旨在将DAC/MDAC系统用作新的入口点，以研究生长和发育模式中的上皮 - 间质相互作用。 由于DAC可能是人类分裂手/足部畸形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。