Chromatin maintenance and sister chromatid differentiation

染色质维持和姐妹染色单体分化

• 批准号: 7944767
• 负责人: PETER M LANSDORP
• 金额: $ 23.69万
• 依托单位: BRITISH COLUMBIA CANCER AGENCY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7944767
• 关键词: Address; Area; Biology; Cell Fate Control; Cell Therapy; Cell division; Cell model; Cells; Centrosome; Chromatin; Chromosomes; DNA; DNA Sequence; DNA biosynthesis; Development; Disease; Elements; Epigenetic Process; Gene Expression; Generations; In Vitro; Inherited; Kinetochores; Lead; Maintenance; Malignant - descriptor; Malignant Neoplasms; Microtubules; Mitosis; Modeling; Molecular; Mothers; Mutation; Organism; Research; Sister; Sister Chromatid; Sorting - Cell Movement; Stem cells; Techniques; Testing; Variant; base; cell type; daughter cell; imprint; in vivo; induced pluripotent stem cell; novel; public health relevance; research study; segregation; self-renewal; therapy development

DESCRIPTION (provided by applicant): Following replication of parental DNA template strands, sister chromatids are expected to have exactly the same DNA sequence except for mutations resulting from DNA replication itself. How epigenetic marks are transmitted to the next cell generation during cell division is less clear. Epigenetic marks that are not lost prior to mitosis are either distributed randomly between sister chromatids or assigned to a specific sister chromatid e.g. depending on whether the parental DNA template strand was replicated by either leading or the lagging strand DNA replication. Alternatively, sister chromatids could be imprinted in a strand-specific manner. Chromatin differences between sister chromatids could be functionally insignificant or lead to "stochastic" differences in the expression of genes between daughter cells. Epigenetic differences between sister chromatids could also be involved in cell fate regulation if microtubules originating from "mother' centrosomes were to prefer kinetochores present on just one of the two sister chromatids of specific chromosomes. Until recently it was not possible to reliably identify and distinguish sister chromatids. However, we recently found that DNA template strand sequences can be reliably used to identify sister chromatids. These novel techniques will be used to study the possibility of epigenetic differences between sister chromatids and their functional implications. The proposed studies have three specific aims: 1. Study gene expression in relation to specific sister chromatids that were inherited in single cells. 2. Study chromatin marks on sorted sister chromatids containing either "Watson" or "Crick" DNA template strand sequences. 3. Follow the segregation of sister chromatids from specific chromosomes into specific cell types in vitro and in vivo. The proposed studies towards these complementary specific aims will clarify whether chromatin differences between sister chromatids exist and if so, whether such differences are relevant to stochastic variation in gene expression between daughter cells and cell fate decisions and the development in multicellular organisms. Importantly, the proposed studies will answer a question which has not been addressed before: does it matter which sister chromatids are inherited by a given daughter cell? If the answer is affirmative, the proposed studies and experimental approaches will pave the way for further studies of an entirely novel field of research: chromatin replication and sister chromatid differentiation. The implications of this type of research are hard to predict but range from the identification of novel targets for therapy and the development of more effective cell therapies starting from (induced) pluripotent stem cells to more effective strategies that target self-renewal in normal and malignant stem cells. PUBLIC HEALTH RELEVANCE: Following DNA replication, every chromosome has two sister chromatids which will each end up in the two daughter cells. The proposed studies will answer a fundamental question that could not be addressed before: does it matter which sister chromatid is inherited by a given daughter cell? If the answer is yes, ideas about how disease is caused in a wide spectrum of disorders ranging from cancer to developmental abnormalities will have to be adjusted.

描述（由申请人提供）：在亲本 DNA 模板链复制后，除了 DNA 复制本身引起的突变外，预计姐妹染色单体将具有完全相同的 DNA 序列。在细胞分裂过程中表观遗传标记如何传递到下一代细胞尚不清楚。有丝分裂前未丢失的表观遗传标记要么随机分布在姐妹染色单体之间，要么分配给特定的姐妹染色单体，例如取决于亲本 DNA 模板链是通过前导链还是滞后链 DNA 复制进行复制。或者，可以以链特异性方式印记姐妹染色单体。姐妹染色单体之间的染色质差异在功能上可能微不足道，或者导致子细胞之间基因表达的“随机”差异。如果源自“母亲”中心体的微管更喜欢仅存在于特定染色体的两个姐妹染色单体之一上的动粒，则姐妹染色单体之间的表观遗传差异也可能参与细胞命运调节。直到最近，还不可能可靠地识别和区分姐妹染色单体。然而，我们最近发现DNA模板链序列可以可靠地用于识别姐妹染色单体。这些新颖的研究 技术将用于研究姐妹染色单体之间表观遗传差异的可能性及其功能影响。拟议的研究有三个具体目标： 1. 研究与单细胞中遗传的特定姐妹染色单体相关的基因表达。 2. 研究含有“Watson”或“Crick”DNA 模板链序列的分选姐妹染色单体上的染色质标记。 3. 遵循姐妹染色单体与特定染色单体的分离 在体外和体内将染色体转化为特定的细胞类型。针对这些互补的特定目标的拟议研究将阐明姐妹染色单体之间是否存在染色质差异，如果存在，这种差异是否与子细胞之间基因表达的随机变异以及细胞命运决定和多细胞生物体的发育有关。重要的是，拟议的研究将回答一个以前没有解决过的问题：哪些姐妹染色单体重要吗？ 由给定的子细胞遗传？如果答案是肯定的，所提出的研究和实验方法将为进一步研究一个全新的研究领域铺平道路：染色质复制和姐妹染色单体分化。这类研究的影响很难预测，但范围广泛，从识别新的治疗靶点和开发从（诱导的）多能干细胞开始的更有效的细胞疗法，到针对正常和正常细胞自我更新的更有效的策略。 恶性干细胞。 公共卫生相关性：DNA 复制后，每条染色体都有两个姐妹染色单体，每个姐妹染色单体最终都会进入两个子细胞。拟议的研究将回答一个以前无法解决的基本问题：给定子细胞遗传哪个姐妹染色单体重要吗？如果答案是肯定的，那么关于从癌症到发育异常等一系列疾病是如何引起疾病的想法就必须进行调整。