ANALYSIS OF CHROMATIN REMODELING IN MAMMARY GLAND DEVELOPMENT USING TILING ARRAYS

描述(由申请人提供)：染色质结构和转录调节之间的相互作用在整个发育和分化的基因调控中起着重要的作用。由于乳腺主要在出生后发育，青春期和妊娠期的激素严格调控其组织特异性基因的表达，因此它是研究染色质重塑调控发育过程的一般机制的良好模型系统。这项研究的长期目标是确定染色质重塑在乳腺成熟和哺乳调节中所起的作用，并确定基因组中在这些过程中起调控作用的相关区域。许多研究已经确定了在发育过程中参与乳腺特异基因转录调控的因素。然而，这些基因在染色质构象(表观遗传学)水平上被全球调控以定义腺体的发育和分化的机制受到的关注要少得多。我们假设染色质重塑发生在乳腺发育和分化过程中，是组织特异性表达模式调控的组成部分，组织特异性表达模式传递腺体成熟所需的细胞记忆。随着CHIP-CHIP的最新发展，一种结合了染色质免疫沉淀(CHIP)和高通量寡核苷酸拼接阵列(CHIP)的新技术现在有可能在全球范围内解决这一问题。我们将使用芯片在小鼠的非乳腺、非定位和哺乳期乳腺组织中建立组蛋白修饰(目标1a)和RNA聚合酶-II(目标1b)的组织和发育阶段特异性模式。由于牛奶蛋白基因在功能分化的乳腺上皮细胞中表达，我们的研究将集中在包含这些基因的基因组区域，以及其他发育调节基因。这些研究将为调节乳腺发育和哺乳的因素和途径带来新的知识，并在操纵这些过程以造福母婴方面开辟新的领域。此外，它们将为理解决定特定组织分化和器官发生的表观遗传变化提供基础。 公共卫生相关声明：牛奶是新生儿的主要营养来源，它为所有哺乳动物物种的新生儿的健康成长和发育提供了所有必要的成分。然而，我们对建立和维持哺乳期所涉及的因素的了解还远远不够。特别是，DNA包装扮演的角色还没有得到很好的确立。在这项研究中，我们将在基因组范围内研究发育中的乳腺中的DNA包装。这些研究将为理解决定特定组织分化和器官发生的机制提供基础。

DESCRIPTION (provided by applicant): The interplay between chromatin structure and transcriptional regulators has an important role in gene regulation throughout development and differentiation. Because the mammary gland develops mostly postnatally and the hormones of puberty and pregnancy tightly regulate its tissue specific gene expression, it makes an excellent model system to study the mechanisms by which chromatin remodeling regulates developmental processes in general. The long-term goal of this research is to determine the role chromatin remodeling plays in the maturation of the mammary gland and regulation of lactation, and identify the pertinent regions in the genome that function as regulatory elements in these processes. Numerous studies have identified the factors involved in transcriptional regulation of mammary specific genes during development. However, the mechanisms by which these genes are regulated globally, at the level of chromatin conformation (epigenetically), to define development and differentiation of the gland have received much less attention. We hypothesize that chromatin remodeling occurs in the mammary gland during development and differentiation, and is an integral part of the regulation of the tissue-specific expression patterns that convey the cellular memory needed for the gland's maturation. A global approach to this problem is now possible with the recent development of ChIP-chip, a new technology combining Chromatin Immuno-precipitation (ChIP) and high-throughput oligonucleotide-tiling arrays (chip). We will use ChIP-chip to establish tissue- and developmental stage-specific patterns of histone modifications (Aim 1a) and RNA-polymerase-II (Aim 1b), in non-mammary, non-locating and lactating mammary gland tissue of the mouse. As milk protein genes are expressed in functionally differentiated mammary epithelial cells, our studies will focus on the genomic domains encompassing these genes, and other developmentally regulated genes. These studies will bring about new knowledge of the factors and pathways regulating mammary gland development and lactation, opening new frontiers in the manipulation of these processes to benefit mother and child. In addition, they will provide a foundation for understanding epigenetic changes that determine differentiation and organogenesis of specific tissues. Public Health Relevance Statement: Milk is the primary source of nutrition for neonates it provides all the essential components for healthy growth and development of newborns of all mammalian species. However, our knowledge of the factors involved in establishing and maintaining lactation is far from complete. In particular the role DNA packaging plays is not well established. In this study we will investigate the DNA packaging in the developing mammary gland at a genome wide scale. These studies will provide a foundation for understanding the mechanisms that determine differentiation and organogenesis of specific tissues.