Role of Ovol Genes in Epidermal Development

性状（由申请方提供）：皮肤表皮来源于多能性外胚层。在外胚层细胞成为滤泡间表皮的过程中，它至少面临三个关键决定：1）不成为神经细胞，2）不成为附属细胞，3）自我更新（如干细胞或祖细胞通常所做的那样），或停止增殖并最终分化为高度特化的细胞，该细胞具有生物体生存的基本保护功能。这些选择是如何做出的？哪些基因或遗传途径控制或调节这些选择？如果这些基因/通路出错会发生什么？我的研究的长期目标是使用多学科方法来解决这些重要问题，这些问题不仅会影响对皮肤干细胞增殖和分化的理解，还会影响对上皮发育和分化机制的理解。该建议的重点是解决两个小鼠卵细胞基因，Ovol 1和Ovol 2，编码锌指转录因子，在表皮规格，增殖和分化的作用。有三个具体目标：1）表征Ovol 2在胚胎干（ES）细胞增殖、外胚层分化和表皮特化中的作用。我们将产生Ovol 2缺陷的ES细胞，并分析其体外增殖和存活。我们将采用体外培养系统，使ES细胞分化为表皮细胞，并监测野生型和Ovol 2缺陷型ES细胞的表皮分化。我们将进行嵌合小鼠分析，以检查Ovol 2缺陷的ES细胞在促进皮肤表皮的内在能力。2)描述Ovol 2在表皮增殖和分化中的作用。我们将通过表皮特异性Ovol 2敲除小鼠的产生和分析来检查Ovol 2在表皮中的功能，特别是测试Ovol 2是表皮干细胞/祖细胞的自我更新和/或增殖所需的假设。3)研究Ovol 1在基因表达和生长停滞中的作用机制。我们将进行生物化学研究，以测试的假设，Ovol 1蛋白直接抑制c-Myc和Id 2的表达，通过竞争与c-Myb的结合，并通过招募HDAC到他们的启动子，从而促进生长停滞。此外，我们将采用转基因“显性阳性”方法来进一步研究Ovol 1在发育中的表皮中调节增殖/分化的体内作用。

DESCRIPTION (provided by applicant): Skin epidermis is derived from the pluripotent ectoderm. In an ectodermal cell's path to become interfollicular epidermis, it faces at least three critical decisions: 1) not to become a neural cell, 2) not to become an appendage cell, 3) to self-renew (as a stem or progenitor cell normally does), or to cease proliferation and terminally differentiate into a highly specialized cell that carries an essential protective function for the organism's survival. How are these choices made? What genes or genetic pathways govern or modulate these choices? What happens if these genes/pathways go awry? The long-term goal of my research is to use a multidisciplinary approach to address these important questions that will impact the understanding of not only stem cell proliferation and differentiation in skin, but also the mechanisms of epithelial development and differentiation in general. This proposal focuses on addressing the role of two mouse Ovo genes, Ovol1 and Ovol2, encoding zinc finger transcription factors, in epidermal specification, proliferation, and differentiation. There are three specific aims: 1) Characterize the role of Ovol2 in embryonic stem (ES) cell proliferation, ectodermal differentiation, and epidermal specification. We will generate ES cells deficient in Ovol2, and analyze their proliferation and survival in vitro. We will adapt an in vitro culture system that allows the differentiation of ES cells into epidermal cells, and monitor epidermal differentiation of wild-type and Ovol2-deficient ES cells. We will perform chimeric mouse analysis to examine the intrinsic ability of Ovol2-deficient ES cells in contributing to the skin epidermis. 2) Characterize the role of Ovol2 in epidermal proliferation and differentiation. We will examine the function of Ovol2 in epidermis through the generation and analysis of epidermis-specific Ovol2 knockout mice, particularly testing the hypothesis that Ovol2 is required for self- renewal and/or proliferation of epidermal stem/progenitor cells. 3) Investigate the mechanism of Ovol1 function in gene expression and growth arrest. We will perform biochemical studies to test the hypothesis that Ovol1 protein directly represses c-Myc and Id2 expression by competing with c-Myb for binding and by recruiting HDACs to their promoters, thereby facilitating growth arrest. Furthermore, we will employ a transgenic "dominant positive" approach to further address the in vivo role of Ovoll in the regulation of proliferation/differentiation in developing epidermis.