Vernalization a cold-induced regulatory network establishing cellular memory

细胞分化--在多细胞生物体的发育过程中，总是涉及模式的变化 关于基因表达的。在许多发育项目中，基因表达模式的某些关键变化 在本质上是表观遗传的；也就是说，这种基因表达的变化在随后的细胞中保持稳定 在没有引起变化的原始信号的情况下出现分歧。在动物身上，表观遗传开关 通常“锁定”发育命运，例如在胚胎形成期间建立身体计划时发生的情况。 在许多植物中，春化引起的类似的表观遗传开关被用来控制生殖。 能力。春化是植物测量冬季寒冷暴露时间的过程 而且，在感觉到足够长的寒冷时间后，获得来年春天开花的能力。 开花能力源于开花抑制基因、开花基因的表观遗传沉默。 C(FLC)，通过对FLC染色质的组蛋白进行一系列修饰。我们将结合对自然界的研究 变异、突变筛选、蛋白质相互作用筛选和全基因组基因表达模式 确定春化网络的构成要素。我们将在FLC中定义具体的更改 伴随着能力获得的染色质。然后，我们将讨论以下角色和交互 基因产物与春化有关。 我们工作的一个长期目标是了解基因调控网络是如何运作的。监管机构 我们建议研究的网络与参与身体规划和器官形成的网络有相似之处 动物。此外，我们正在研究的表观遗传开关在减数分裂过程中被重置，这也是一种 哺乳动物基因组印迹的特征。对表观遗传过程的不当调控可能是基础 发育异常事件和某些疾病状态，如癌症。对…的总体了解 在一系列多细胞生物体中的表观遗传调控最终应该有助于发育 治疗疾病状态的策略。

Cellular differentiation-in the development of multicellular organisms invariably involves changes-in patterns of gene expression. In many developmental programs, certain key changes in patterns of gene expression are epigenetic in nature; that is, such changes in gene expression remain stable through subsequent cell divisions in the absence of the original signal that induced the changes. In animals, epigenetic switches often "lock in" developmental fates such as occurs in establishment of the body plan during embryogenesis. In many plants, a comparable epigenetic switch resulting from vernalization is used to govern reproductive competence. Vernalization is the process by which plants measure the duration of exposure to winter's cold and, after perceiving a sufficient duration of cold, acquire competenceto flower the following spring. Competence to flower results from the epigenetic silencing of a flowering represser, FLOWERING LOCUS C (FLC), via a series of modifications to histones of FLC chromatin. We will combine studies of natural variation, mutant screens, protein interaction screens, and genome-wide gene expression patterns to identify constitutive elements of the vernalization network. We will define the specific changes in FLC chromatin that accompany the acquisition of competence. We will then address the roles and interaction of the genes product involved in vernalization. A long-term goal of our work is to understand how genetic regulatory networks operate. The regulatory network that we propose to study has similarities to those involved in body plan and organ formation in animals. Moreover,the epigenetic switch that we are studying is reset during meiosis which is also a feature of genomic imprinting in mammals. Improper regulation of epigenetic processes can underlie abnormal developmental events and some disease states such as cancer. A general understanding of epigenetic regulation in a range of multi-cellular organisms should ultimately contribute to the development of strategies to treat disease states.