BRN-4--ROLE OF A POU-DOMAIN IN BRAIN DEVELOPMENT

这项提议的主要目标是阐明 指导哺乳动物前脑的发育。人物刻画 一种名为Brain-4(BRN-4)的新POU结构域基因将被用作 这一更广泛目标的范例。POU结构域基因家族的成员 编码转录因子；到目前为止，其中几个因子已经 被证明在垂体前叶的发育中起关键作用 从线虫到其他物种的腺体和周围神经系统 对人类来说。BRN-4基因表达的时空模式 发展表明BRN-4-在建立 胚胎前脑内的形态界限。在怀孕中期 胚胎、杂交组织化学分析表明BRN-4 表达广泛分布于中枢神经系统，包括 前脑内的脑室区域。然而，BRN-4的表达不是 发现于这些胚胎的前脑的最顶端。这个 BRN-4在胚胎神经系统中的表达程度 在胎儿晚期和成年时，变得仅限于一小部分结构 大脑。BAN-4表达的进一步杂交组织化学分析 在小鼠个体发育过程中，将阐明 BAN-4基因及其作为心室区标志物的应用 与前脑神经发生的关系。要研究分子 BAN-4表达的时空调控基础，即顺式调控。 将对该基因的活性调控元件进行表征。一次 重要的顺式活性序列被鉴定，DNA结合分析将被 用于启动转录因子的表征 识别这些序列。研究BAN-4基因的作用 产品在整个有机体的背景下，一个小鼠的谱系 在BAN-4基因中包含零突变的基因将使用 胚胎干细胞技术。这种方法将直接解决 BAN-4在哺乳动物胚胎发育中的作用。这个 BAN-4基因e的特性提供了一个有价值的工具 阐述前脑发育的分子基础。基因分析 神经发生早期的调控事件将有助于 了解中枢神经系统的个体发育，并将提供 对影响神经系统的发育异常的重要见解 功能。

The broad goal of this proposal is to elucidate molecule mechanisms that direct the development of the mammalian forebrain. The characterization of a novel POU-domain gene called Brain-4 (Brn-4) will be used as a paradigm for this broader goal. Members of the POU-domain gene family encode transcription factors; to date, several of these factors have been shown to play critical roles in the development of the anterior pituitary gland and the peripheral nervous system in species ranging from nematodes to man. The spatiotemporal pattern of Brn-4 expression during development suggests a role for Brn-4- in the establishment of morphological boundaries within the embryonic forebrain. In midgestation embryos, hybridization histochemical analyses demonstrate that Brn-4 expression is widely distributed in the central nervous system, including ventricular zones within the forebrain. However, Brn-4 expression is not found in the most rostral aspects of the forebrain in these embryos. The extent of Brn-4 expression observed in the embryonic nervous system becomes restricted to a small subset of structure in late fetal and adult brains. Further hybridization histochemical analyses of Ban-4 expression during mouse ontogeny will clarify the spatial an temporal expression of the Ban-4 gene, its utility as a ventricular zone marker, and its relationship to neurogenesis in the forebrain. To study the molecular basis for the spatiotemporal regulation of Ban-4 expression, the cis- active regulatory element of the gene will be characterized. Once important cis-active sequences are identified, DNA binding assay will be employed to initiate the characterization of transcription factors recognizing these sequences. To investigate the role of the Ban-4 gene product in the context of the entire organism, a mouse pedigree containing a null mutation in the Ban-4 gene will be generated using Embryonic Stem (ES) cell technology. This approach will directly address the function of Ban-4 during mammalian embryogenesis. The characterization of Ban-4 gene e provides a valuable tool with which to address the molecular basis of forebrain development. Analysis of gene regulatory events during the early stages of neurogenesis will help to understand the ontogeny of the central nervous system, and will provide important insights into developmental anomalies affecting nervous system function.