Regulation of embryonic cell fate decision by histone methylation

组蛋白甲基化调控胚胎细胞命运决定

基本信息

批准号：
10021408
负责人：
Juan D Rodriguez
金额：
$ 4.55万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-16 至 2022-09-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10021408
关键词：
Affect Animals Caenorhabditis elegans Cell division Cells Cessation of life Child Child Mortality Childhood Chromatin Chromatin Remodeling Factor Congenital Abnormality DNA Packaging Defect Deposition Development Developmental Delay Disorders Disease Ectopic Expression Embryo Embryonic Development Enzymes Epigenetic Process Failure Fertilization Gene Expression Generations Genes Genetic Transcription Grant Heritability Histones Human Individual Infant Inherited Intellectual functioning disability KDM1A gene Kabuki Make-Up Syndrome Learning Maintenance Methylation Methyltransferase Mitotic Modeling Mutation Neurodevelopmental Disorder Oocytes Organ Orthologous Gene Patients Phenotype RNA Interference Regulation Resolution Somatic Cell Specific qualifier value Sterility Syndrome Technology Tissues Totipotency United States blastomere structure causal variant confocal imaging craniofacial genome-wide histone demethylase histone methylation malformation mutant neuronal cell body prevent single-cell RNA sequencing transgenerational epigenetic inheritance

项目摘要

PROJECT SUMMARY: Every year about 7.9 million infants are born with serious birth defects, including craniofacial, intellectual disabilities, organs malformation and developmental delays. More importantly birth defects are the leading cause of child mortality in United States. Recently, many children with birth defects were identified as having mutations in histone modifying enzymes. These include Kabuki Syndrome patients and 3 children with mutations in the histone demethylase LSD1/KDM1. These children all have neurodevelopmental disorders. It is thought that the failure to properly regulate histone methylation in these patients leads to inappropriate transcription. However, it is unclear to what extent inappropriate transcription is heritable within developing embryos. It is also unclear how inappropriate transcription leads to defects. We have recently developed a C. elegans model of inappropriately inherited histone methylation due to failure in epigenetic reprogramming at fertilization. In C. elegans, two epigenetic enzymes, the H3K4me2 demethylase, SPR-5 (ortholog of LSD1), and the H3K9 methyltransferase, MET-2 (ortholog of SetDB1), are maternally deposited into the oocyte. These chromatin modifiers cooperate to reestablish the epigenetic ground state by modifying histone methylation. Progeny of worms lacking SPR-5 and MET-2 accumulate high levels of H3K4me2, resulting in complete sterility and developmental delay, caused by the improper maintenance of germline expression in the soma. Importantly, the C. elegans embryonic lineage is completely invariant. As a result, spr-5;met-2 mutants provide a unique opportunity to understand the rules governing how inappropriate histone methylation affects transcription and cell fate at the single cell level. To do this, I will use confocal imaging to perform automated lineage tracing. This will enable me to detect defects in the timing of cell division, the number of cell divisions, and the survival/death of individual cells in every embryonic lineage. I will combine this with single cell RNA- seq analysis to determine cell by cell, which somatic cells inappropriate express germline genes. By comparing the lineage defects to the inappropriate expression of germline genes in every cell, I will learn the rules governing how inappropriate histone methylation affects transcription and cell fate in developing tissues. Thus, successful completion of this grant will provide a framework for understanding childhood diseases, such as Kabuki Syndrome, caused by mutations in histone modifying enzymes.

项目摘要：每年约有790万婴儿出生有严重的先天缺陷，包括颅面，智力残疾，器官畸形和发展延迟。更重要的是先天缺陷是美国儿童死亡率的主要原因。最近，许多患有先天缺陷的儿童被确定为在组蛋白修饰酶中具有突变。其中包括Kabuki综合征患者和3名儿童组蛋白脱甲基酶LSD1/KDM1中的突变。这些孩子都患有神经发育障碍。这是认为这些患者中未正确调节组蛋白甲基化的失败导致不适当转录。但是，目前尚不清楚在发展中遗传的不适当转录在多大程度上是可遗传的胚胎。还不清楚不适当的转录如何导致缺陷。我们最近开发了C。秀丽隐杆线虫的模型由于表观遗传重编程失败而导致的不恰当遗传的组蛋白甲基化受精。在秀丽隐杆线虫中，两种表观遗传酶，H3K4me2脱甲基酶，Spr-5（LSD1的直系同源）， H3K9甲基转移酶Met-2（setDB1的直系同源物）被母体沉积到卵母细胞中。这些染色质修饰剂通过修饰组蛋白甲基化来合作以重新建立表观遗传基态。缺乏SPR-5和Met-2的蠕虫后代会积聚高水平的H3K4ME2，导致完整不育和发育延迟，是由于SOMA中种系表达的不当维持而引起的。重要的是，秀丽隐杆线虫胚胎谱系是完全不变的。结果，spr-5; met-2突变体提供一个独特的机会来了解管理不当组蛋白如何影响的规则单细胞水平的转录和细胞命运。为此，我将使用共聚焦成像进行自动化谱系跟踪。这将使我能够检测细胞分裂时机的缺陷，细胞分裂的数量，以及每个胚胎谱系中单个细胞的生存/死亡。我将与单细胞RNA-结合使用 SEQ分析以通过细胞确定细胞，哪些细胞不适当地表达生殖基因。通过比较在每个细胞中种系基因不适当表达的谱系缺陷，我将学习规则管理不适当的组蛋白甲基化如何影响发展组织中的转录和细胞命运。因此，成功完成这笔赠款将为了解儿童疾病的框架，例如 Kabuki综合征，由组蛋白修饰酶突变引起。