Development of the vertebrate embryo requires strict coordination of a highly complex series of signaling cascades, that drive cell proliferation, differentiation, migration, and the general morphogenetic program. Members of the Map kinase signaling pathway are repeatedly required throughout development to activate the downstream effectors, ERK, p38, and JNK. Regulation of these pathways occurs at many levels in the signaling cascade, with the Map3Ks playing an essential role in target selection. The thousand and one amino acid kinases (Taoks) are Map3Ks that have been shown to activate both p38 and JNK and are linked to neurodevelopment in both invertebrate and vertebrate organisms. In vertebrates, there are three Taok paralogs (Taok1, Taok2, and Taok3) which have not yet been ascribed a role in early development. Here we describe the spatiotemporal expression of Taok1, Taok2, and Taok3 in the model organism Xenopus laevis. The X. laevis Tao kinases share roughly 80% identity to each other, with the bulk of the conservation in the kinase domain. Taok1 and Taok3 are highly expressed in pre-gastrula and gastrula stage embryos, with initial expression localized to the animal pole and later expression in the ectoderm and mesoderm. All three Taoks are expressed in the neural and tailbud stages, with overlapping expression in the neural tube, notochord, and many anterior structures (including branchial arches, brain, otic vesicles, and eye). The expression patterns described here provide evidence that the Tao kinases may play a central role in early development, in addition to their function during neural development, and establish a framework to better understand the developmental roles of Tao kinase signaling.

脊椎动物胚胎的发育需要一系列高度复杂的信号级联的严格协调，这些级联驱动细胞增殖、分化、迁移和一般形态发生程序。在整个发育过程中，反复需要 Map 激酶信号通路的成员来激活下游效应器 ERK、p38 和 JNK。这些通路的调节发生在信号级联的多个层面，其中 Map3K 在靶标选择中发挥着重要作用。一千零一个氨基酸激酶 (Taoks) 是 Map3K，已被证明可以激活 p38 和 JNK，并且与无脊椎动物和脊椎动物的神经发育有关。在脊椎动物中，存在三个Taok旁系同源物（Taok1、Taok2和Taok3），它们在早期发育中尚未发挥作用。在这里，我们描述了模式生物非洲爪蟾中Taok1、Taok2和Taok3的时空表达。X.laevisTao激酶彼此具有大约 80% 的同一性，其中大部分保守性位于激酶结构域中。Taok1和Taok3在原肠胚前和原肠胚期胚胎中高表达，最初表达位于动物极，后来在外胚层和中胚层表达。所有三种 Taok 均在神经和尾芽阶段表达，在神经管、脊索和许多前部结构（包括鳃弓、大脑、耳囊和眼睛）中重叠表达。这里描述的表达模式提供了证据，表明除了在神经发育过程中的功能之外，Tao 激酶可能在早期发育中发挥核心作用，并建立了一个框架来更好地理解 Tai 激酶信号传导的发育作用。