SPEMANN'S ORGANIZER ACTIVITY AND HOMEOBOX GENES

一个同源异型盒基因gooseclike，在背部胚孔中特异表达 利普被隔离了。Goosecid，特别有趣，因为它是：1) 由激活素(一种中胚层诱导生长因子)直接激活，2) 仅在背侧唇区中胚层特异表达，3)仅在唇背区中胚层表达 在原肠形成过程中表达，以及4)能够诱导 当注射到早期胚胎的卵裂球中时，次级轴。这些 鹅类同源盒基因的特性表明该基因在 原肠发育过程中的基本调节作用。 将利用两种原位研究方法研究鹅类固醇的表达模式 杂交和抗体染色技术。为了更好地理解 鹅类同源域蛋白的功能，多种表达 构建物将被显微注射到单个胚胎的卵裂球中 分析类鹅皮质素的表达对细胞命运的影响。 将尝试获得功能损失、功能增益和 微量注射抗体、正义和反义显性-负性突变体 RNA和寡核苷酸。为了了解激活素介导的 信号转导途径，鹅类启动子报告基因构建 将被显微注射到胚胎中，激活素反应元件 鹅类启动子鉴定。因此，身份识别和 介导信号转导的分子的特征可以是 完成了。将尝试分离鹅类目的基因 使用从鹅卵样体显微注射胚胎中获得的差异探针。

A homeobox gene goosecoid, specifically expressed in the dorsal blastopore lip was isolated. Goosecoid, is particularly interesting since it is: 1) directly activated by activin (a mesoderm-inducing growth factor), 2) specifically expressed in the mesoderm of dorsal lip region, 3) only expressed during the gastrulation process, and 4) capable of inducing a secondary axis when injected into a blastomere of an early embryo. These properties of the goosecoid homeobox gene suggest that the gene plays fundamental regulatory roles during gastrulation. Expression pattern of goosecoid will be studied using both in situ hybridization and antibody staining techniques. In order to understand the function of the goosecoid homeodomain protein, various expression constructs will be microinjected into an individual blastomere of embryos to analyze the cell fate change brought by the expression of goosecoid. Attempts will be made to obtain loss-of-function, gain-of-function, and dominant-negative mutants by microinjecting antibodies, sense and antisense RNAs and oligonucleotides. In order to understand the activin-mediated signal transduction pathway, goosecoid promoter reporter gene constructs will be microinjected into embryos and the activin responsive element in the goosecoid promoter identified. Thus, the identification and characterization of the molecules mediating the signal transduction can be accomplished. Isolation of the goosecoid target genes will be attempted using differential probes obtained from goosecoid microinjected embryos.