PATTERN FORMATION DURING EARLY XENOPUS DEVELOPMENT

包含基因的同源框是一个基因家族，已经在 果蝇在发育过程中控制图案的形成。这些基因 编码蛋白质，以序列特定的方式与DNA结合。他们 含有一个180个碱基的保守DNA结构域，称为同源异型盒。我们已经隔离了 几个包含在非洲爪哇早期被激活的基因的同源盒 发展。我们已经确定了它们的时间和空间表达 采用Northern印迹分析和原位杂交的方法。至少 其中一些基因在原肠形成期间表达，这是一个关键时刻 中胚层和神经诱导的发育期 地点。对这些基因的序列分析表明，其中一些是 与之前描述的其他物种(如小鼠)的基因同源 和果蝇，其他的还没有被描述。其中一个新的 同源框基因XDLL-1与果蝇远端缺失基因同源 一家人。它表达于胚胎的骨水泥腺体、神经脊。 衍生的内脏弓和前脑。它的时空表达 模式表明，该基因参与了前脑和颅脑- 面部发育。除了同源异型盒基因家族，我们还有 分离出Fork Head基因家族的新成员。个别成员 有一种非常有趣的表达模式，至少 其中一些是癌基因。第一个非洲爪哇叉头基因XFKH1具有 许多非常有趣的特征。它在以下时间或之后不久被激活 胚胎背侧缘骨中胚泡的过渡。在……里面 早期原肠幼虫仅限于组织者区域。在后期阶段 它在脊索和神经底板表达。此外，它还 是由隔离动物帽子中的激活素诱导的。它的表达模式 激活素的可诱导性表明该基因具有关键的 非洲爪哇胚胎早期模式形成的重要性。

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. At least some of these genes are expressed during gastrulation, a critical time period of development at which mesodermal and neural induction takes place. Sequence analysis of these genes revealed that some of them are homologous to previously described genes in other species such as mouse and Drosophila, others have not yet been described. One of the new homeobox genes, the XDLL-1, is homologous to Drosophila Distal-less gene family. It is expressed in the embryonic cement gland, neural crest derived visceral arches and forebrain. Its temporo-spatial expression pattern indicates that this gene is involved in forebrain and cranio- facial development. 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 midblastula 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 floor plate. 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.