PATTERN FORMATION DURING EARLY XENOPUS DEVELOPMENT

非洲爪蟾早期发育过程中的模式形成

• 批准号: 5200770
• 负责人: M A JAMRICH
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5200770
• 关键词: DNA binding protein; Xenopus; developmental genetics; developmental neurobiology; ectoderm; embryo /fetus; embryogenesis; gene expression; gene induction /repression; growth factor; growth factor receptors; homeobox genes; in situ hybridization; inhibin; mesoderm; neural crest; neural plate /tube; neurogenesis; nonmammalian vertebrate embryology; northern blottings; oncogenes; transcription factor

Homeobox containing genes are a family of genes which have been shown in Drosophila to control pattern formation during development. These genes encode proteins which bind to DNA in a sequence specific manner. They contain a 180 bp conserved DNA domain called a homeobox. We have isolated several homeobox containing genes which are activated during early Xenopus development. We have determined their temporal and spatial expression pattern using Northern blot analysis and in situ hybridization. One of them, called PV.1 is the first transcription factor capable of mediating ventral mesoderm formation in Xenopus. PV.1 is inducible in uncommitted ectoderm by ventralizing growth factor BMP4. Like BMP4, PV.1 is expressed in the ventral marginal zone of gastrulating embryos. Over-expression of PV.1 yields ventralized tadpoles and rescues embryos partially dorsalized by LiCl treatment. In animal caps, PV.1 ventralizes induction by activin. All of these effects mimic those previously reported for BMP4. Finally, we have shown that PV.1 counteracts the dorsolaizing effects of dominant negative BMP4 receptor. These observations suggest that PV.1 is a likely target in the BMP4 signaling pathway regulating expression of genes necessary for the formation of ventral mesoderm. In addition to the homeobox gene family we have isolated new members of the Fork head gene family. The individual members of this family have a highly interesting expression pattern and at least some of them are oncogenes. The first Xenopus Fork head gene XFKH1 has many highly interesting features. It is activated at, or shortly after, the mid-blastula transition in the dorsal marginal bone of the embryo. In early gastrulae it is restricted to the organizer region. At later stages it is expressed in the notochord and neural organizer region. Furthermore, it is inducible by activin in isolated animal caps. Its expression pattern and inducibility by activin suggests that this gene has a critical importance for early pattern formation in Xenopus embryos. Its expression pattern and inducibility by activin suggests that this gene has a critical importance for early pattern formation in Xenopus embryos. We have shown that this gene belongs to a larger family of Fork head genes, which, like homeobox genes are involved in different aspects of pattern formation and cell differentiation. In addition, we have initiated similar research into pattern formation in Zebrafish embryos.

含有同源异型盒的基因是一个基因家族， 果蝇在发育过程中控制图案的形成。 这些基因 编码以序列特异性方式与DNA结合的蛋白质。 他们 含有一个180 bp的保守DNA结构域，称为同源框。 我们有 分离出几个含有同源框的基因，这些基因在 早期爪蟾的发育 我们已经确定了他们的时间和空间 使用北方印迹分析和原位杂交分析表达模式 杂交方法 其中之一，称为PV.1是第一个转录 在爪蟾中能够介导腹侧中胚层形成的因子。 PV.1 在未定型外胚层中可通过腹侧化生长因子BMP 4诱导。 与BMP 4一样，PV.1表达于原肠胚的腹侧边缘区， 胚胎 PV.1的过表达产生腹侧化的蝌蚪和拯救 LiCl处理的部分背生胚。 在动物帽中，PV.1 使激活素的诱导向腹侧移动。 所有这些效应都模仿了 之前报道过BMP 4。 最后，我们证明了PV.1 抵消显性负性BMP 4受体的背侧化作用。 这些观察结果表明，PV.1是BMP 4中可能的靶点。 信号通路调节基因的表达所必需的 腹侧中胚层的形成。 除了同源异型盒基因家族，我们还分离出了 叉头基因家族 这个家庭的每个成员都有 一个非常有趣的表达模式，至少其中一些是 致癌基因 第一个非洲爪蟾叉头基因XFKH 1具有许多高度同源性， 有趣的特征。 它是激活时，或不久后， 胚胎背侧边缘骨的囊胚中期过渡。 在 在原肠胚早期，它仅限于组织者区。 在稍后 阶段，它在脊索和神经组织者区域表达。 此外，在分离的动物帽中，它可被激活素诱导。 其 表达模式和激活素的诱导表明，该基因 对爪蟾胚胎的早期模式形成至关重要。 它的表达模式和激活素的诱导表明， 一个基因对爪蟾的早期模式形成至关重要 胚胎我们已经证明，这个基因属于一个更大的家庭叉 头部基因，像同源异型盒基因一样， 模式形成和细胞分化。另外我们有 对斑马鱼胚胎的模式形成进行了类似的研究。