PROTEIN/NUCLEIC ACID INTERACTIONS IN VERTEBRATE EMBRYOGENESIS

该计划旨在回答发展中的两个基本问题 生物学 (1)分化中的细胞如何调节 基因在发育过程中的表达？ (2)如何迁移细胞，如 神经嵴细胞在胚胎中找到正确的路径 为了解决第一个问题，我们使用小鼠的分化， 表皮细胞作为一个模型系统，重点是功能和 调节Dlx 3，一个同源结构域基因转录在上层的 表皮 我们已经通过功能增益实验表明，Dlx 3可以 调节，可能直接，结构基因的表达激活 在分化过程的后期。 功能丧失（基因消融） 研究表明，Dlx 3对小鼠的生存至关重要 妊娠期超过11天的胚胎在形成或 基于表达数据假设胎盘的功能。 在酵母和HeLa细胞中的研究表明，Dlx 3作为阳性表达， 转录调节因子 协同因子和靶基因是 目前正在寻求的互动屏幕和减法 杂交方法 调节细胞迁移的问题正在通过分析 受体酪氨酸激酶EphA 4（以前称为Pagliaccio）的功能 或SEK 1）。 EphA 4在退化的中胚层中表达，在EphA 4的亚组中表达。 迁移的颅神经嵴和其他正在迁移的组织，或 重排 它已被证明发挥了关键作用， 脊椎动物后脑中脑节之间边界的形成。我们 已经证明，当这种受体在早期爪蟾胚胎中被激活时， 细胞-细胞粘附显著但短暂地减少， 可能是通过调节钙粘蛋白的功能。 最近的数据显示， 这种对粘附的作用至少部分地由SRC相关的 酪氨酸激酶c-fyn。 进一步研究这种信号通路， 它在发展中作用正在进行中。

This program is aimed at answering two basic questions in developmental biology. (1) How do differentiating cells regulate changing patterns of gene expression during development? (2) How do migrating cells, such as neural crest cells, find their correct paths in the embryo? To address the first question we use the differentiation of murine epidermal cells as a model system, with a focus on the function and regulation of Dlx3, a homeodomain gene transcribed in upper strata of the epidermis. We have shown by gain-of-function experiments that Dlx3 can regulate, possibly directly, the expression of structural genes activated late in the differentiation process. Loss-of-function (gene ablation) studies have revealed that Dlx3 is essential for survival of the mouse embryo beyond 11 days of gestation. A critical function in formation or function of the placenta is hypothesized based on expression data. Studies in yeast and HeLa cells have shown that Dlx3 acts as a positive regulator of transcription. Cooperating factors and target genes are currently being sought by interaction screens and subtractive hybridization methods. The problem of regulating cell migration is being addressed by analyzing the function of a receptor tyrosine kinase, EphA4 (previously Pagliaccio or SEK1). EphA4 is expressed in involuting mesoderm, in a subset of migrating cranial neural crest, and other tissues undergoing migration or rearrangement. It has been shown to play a critical role in the formation of boundaries between segments in the vertebrate hindbrain. We have shown that when this receptor is activated in early Xenopus embryos there is a significant but transient reduction in cell-cell adhesion, probably by modulation of cadherin function. Recent data indicate that this effect on adhesion is mediated at least in part by the src-related tyrosine kinase c-fyn. Further studies on this signaling pathway, and its role in development, are underway.