ROLE OF POU DOMAIN GENES IN EARLY VERTEBRATE DEVELOPMENT

POU转录因子已被证明是重要的， 在发育过程中调节细胞命运的决定。 我们重点 了解一个POU结构域基因XlPOU 2在 早期神经发育 XlPOU 2就在 noggin的神经诱导信号通路。 我们目前的目标是 鉴定XlPOU 2启动子中的头蛋白诱导元件。我们有 通过过度表达XlPOU 2， X1 POU 2基因在胚胎中产物。 XlPOU 2的过度表达 导致原肠胚发育中爪蟾背侧基因功能的抑制 胚胎，导致“无头”表型。 因此，XlPOU 2的 作用似乎仅限于早期原肠胚形成。 XlPOU 2干扰诱导的2度轴的形成 在Wnt信号级联中。 表型X1 POU 2可以被拯救 另一种存在于组织器官中的信号分子。 XlPOU 2阻断激活素诱导的中胚层标志物的表达，如 作为即时反应基因，GSC。 XlPOU 2可抑制gsc 由于它与GSC启动子中的两个元件直接结合， 其对III类POU基因具有特异性。 我们正在测试 XLPOU 2可以抑制gsc启动子的激活。 我们还发现了一个新的POU基因在斑马鱼，太极。 的 太极拳在发育过程中和成年大脑中的表达模式 与其在监管机构方面的潜在作用一致 和/或维持神经干细胞。 太极表情是 与大脑中增殖的未分化细胞有关。 该细胞群可以被BrdU标记，并且不表达两个 神经分化的标志物，乙酰化微管蛋白和 神经丝蛋白 我们正在进一步描述这些细胞 使用另一个与太极共表达的标记物NRP-1（一种RNA 结合蛋白）。 为了进一步了解干细胞在 在哺乳动物的发育过程中，我们试图克隆一种 太极拳。

POU transcription factors have been shown to be important in the regulation of cell fate decisions during development. We have focused on understanding the function of one POU domain gene, XlPOU 2 , in early neural development. XlPOU 2 is immediately downstream in the neural inductive signaling pathway for noggin. Our current goal is to identify noggin inducible elements in the XlPOU 2 promoter. We have examined the role of XlPOU 2 in Spemann's organizer by overexpressing the XlPOU 2 gene product in embryos. The overexpression of XlPOU 2 leads to a suppression of dorsal gene function in gastrulating Xenopus embryos, which results in a "headless" phenotype. Thus, XlPOU2's action appears to be restricted to early gastrulation. XlPOU2 interferes with the formation of a 2 degrees axis induced within the Wnt signaling cascade. The phenotype XlPOU2 can be rescued by chordin, another signaling molecule present in the organzier. XlPOU2 blocks the activin-induced expression of mesoderm markers, such as the immediate response gene, gsc. XlPOU2 may suppress gsc directly, since it binds to two elements in the gsc promoter, both of which are specific for class III POU genes. We are testing whether XLPOU2 can suppress the activation of the gsc promoter. We have also characterized a novel POU gene in zebrafish, taichi. The expression pattern of taichi during development and in the adult brain is consistent with its potential role in regulating the establishment and/or maintenance of neural stem cells. Taichi expression is associated with proliferating, non-differentiated cells of the brain. This cell population can be labeled by BrdU, and does not express two markers of neural differentiation, acetylated tubulin and neurofilament protein. We are characterizing these cells further using another marker that is co-expressed with taichi, NRP-1 (an RNA binding protein). To further understand the role of stem cells in mammalian development, we are attempting to clone a mouse homolog of taichi.