REGULATION OF GENE ACTIVITY IN XENOPUS EARLY DEVELOPMENT

这项工作的长期目标是了解其分子机制。 脊椎动物早期胚胎的基因调控。 对胚胎基因表达至关重要的顺式作用序列将是 通过将克隆基因显微注射到受精蛙卵中来确定。 在鉴定了顺式作用元件之后，凝胶延迟和 将使用DNA酶足迹技术来检测和表征 与调控元件相互作用的DNA结合蛋白。青蛙 系统是这些研究的理想之选，不仅是因为 微量注射，也是因为有非常大量的 胚胎将为分离DNA提供充足的材料来源- 约束性因素。使用这种方法，本文中概述的实验 提案将在两个重要阶段研究基因调控 胚胎发育。 第一，受精卵表达的第一批基因的调控 将对基因组进行检查。调节这些的交互作用因素 基因被认为是母性的，这项提案中的实验寻求 分离和鉴定这些母性调节因子。它是 了解母体因素如何调节合子基因很重要 因为这一步对所有人的成功至关重要 随后的胚胎发育。 其次，在神经发生过程中表达的基因的调节将是 检查过了。神经诱导是发展的经典问题之一。 生物学，但对其机制几乎一无所知。在中国的实验 该提案将确定负责的顺位和反式作用因素 对神经细胞黏附的时间和组织特异性调节 分子(N-CAM)，它是最早被转录的基因之一 对神经诱导的反应。 这些研究将有助于更好地理解转录 脊椎动物胚胎的调控。特别是，关于 对神经基因的调控将有助于全面了解 神经发生，而这反过来将对理解 导致无脑儿和脊柱裂的神经源性缺陷。

The long term aim of this work is to understand the molecular mechanisms of gene regulation in the early vertebrate embryo. The cis-acting sequences essential for embryonic gene expression will be determined by microinjection of cloned genes into fertilized frog eggs. Following identification of the cis-acting elements, gel retardation and DNase footprinting techniques will be used to detect and characterize the DNA-binding proteins that interact with the regulatory elements. The frog system is ideal for these studies, not only because of the ease of microinjection, but also because the availability of very large numbers of embryos will provide an ample source of material for the isolation of DNA- binding factors. Using this approach, the experiments outlined in this proposal will investigate gene regulation at two important stages in embryonic development. Firstly, the regulation of the first genes to be expressed from the zygotic genome will be examined. The trans-acting factors that regulate these genes are expected to be maternal and the experiments in this proposal seek to isolate and characterize these maternal regulatory factors. It is important to understand how maternal factors regulate zygotic gene transcription because this step is critical for the success of all subsequent embryonic development. Secondly, the regulation of genes expressed during neurogenesis will be examined. Neural induction is one of the classic problems of developmental biology but almost nothing is known of its mechanism. The experiments in this proposal will identify the cis and trans-acting factors responsible for the temporal and tissue-specific regulation of the neural cell adhesion molecule, (N-CAM), which is one of the first genes to be transcribed in response to neural induction. These studies will lead to a better understanding of transcriptional regulation in vertebrate embryos. In particular, basic information on the regulation of neural genes will contribute to a complete picture of neurogenesis, and this in turn will be important for understanding the neurogenic defects that result in anencephaly and spina bifida.