Characterization of the role of maternal effect gene Nlrp2 in reproduction

母体效应基因 Nlrp2 在生殖中作用的表征

基本信息

批准号：
10162630
负责人：
IGNATIA B VAN DEN VEYVER
金额：
$ 37.45万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-15 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10162630
关键词：
Affect Beckwith-Wiedemann Syndrome Binding Cell Culture Techniques Cells Child Complement Complex Congenital Abnormality DNA Binding DNA Methylation DNA Modification Methylases Data Defect Dependence Development Disease Embryo Embryo Transfer Embryonic Development Environment Epigenetic Process Event Female Fertilization Fertilization failure Fertilization in Vitro Foundations Future Gametogenesis Gene Expression Genes Genetic Transcription Genome Germ Cells Goals Growth Haploidy Health Homologous Gene Human Hydatidiform Mole In Vitro Infertility Knockout Mice Knowledge Link Modeling Molecular Mus Mutant Strains Mice Mutation Nuclear Oocytes Parents Phenotype Placenta Pregnancy Process Proteins RNA Reader Recurrence Regulation Reproduction Rodent Role Structure Time Totipotent Transcript Translations Work blastocyst demethylation embryo cell experimental study follow-up gene function genome-wide histone modification imprint in utero in vivo loss of function maternal imprint member methylome methylomics molecular phenotype mouse model mutant mutant mouse model neonatal death novel offspring phenotypic data protein complex reproductive reproductive system disorder therapeutic target transcriptome transcriptome sequencing transcriptomics zygote

项目摘要

PROJECT SUMMARY Maternal mutations in human NLRP7 cause pregnancies recurrent hydatidiform molar pregnancies with imprinting defects. Maternal mutations in its highly homologous neighboring gene NLRP2, cause a multi-locus imprinting disorder (MLID) that manifests as Beckwith-Wiedemann syndrome in offspring. Both are associated with abnormal DNA methylation of maternally imprinted genes. Rodents have the Nlrp2 gene, but no Nlrp7. We hypothesized that Nlrp2 may combine functions of both human homologs and generated a Nlrp2-mutant mouse model to study the mechanisms by which its maternal inactivation causes the observed offspring and placental abnormalities. We found that NLRP2 protein is a new member of the subcortical maternal complex (SCMC), a cytoplasmic complex in oocytes that persists in preimplantation embryos with a presumed role in maternal-to- zygote transition and zygotic genome activation, which are the processes by which embryos switch from reliance on maternally contributed transcripts and proteins to their own transcription and translation. We found that a maternal-effect mutation in Nlrp2 disrupts the SCMC, causing Nlrp2-null females to produce fewer and smaller litters with offspring that have birth defects, growth abnormalities, and imprinting defects. In vitro cultured embryos of these Nlrp2-null females have a more severe phenotype with early cleavage-stage arrest. These data for the first time link the SCMC to imprinting reprogramming and indicate that Nlrp2-null mice are an excellent model to study the mechanisms of this interaction. They support the overarching goal of this project, to characterize how maternal loss of NLRP2, a new SCMC protein, alters imprinting in offspring, and how this leads to a range of reproductive phenotypes. Towards this goal, for specific aim 1, we will characterize the cellular and developmental events in the zygote and preimplantation embryo that are at the origin of the reproductive and imprinting phenotypes. For specific aim 2, we will investigate the molecular mechanisms that underlie the reproductive phenotypes of maternal inactivation of Nlrp2 by following up on other interesting early observations, which include that NLRP2 and DNA-methyltransferase 1 (DNMT1) co-localize in preimplantation embryos, and that Nlrp2-deficient oocytes have altered gene expression profiles. For specific aim 3 we will characterize in vivo the variable later developmental abnormalities of embryos and placentas resulting from maternal loss of Nlrp2. This will increase knowledge on the reproductive disorders caused by maternal effect mutations. All phenotyping will be complemented by transcriptomics, methylomics and profiling of DNMT1 binding to fully integrate molecular and phenotypic data. We predict that this work will uncover important new principles of genome reprogramming during gametogenesis and after fertilization and will clarify how the SCMC affects this process. The long-term benefit for human health will include better understanding of multi-locus imprinting disorders and some forms of infertility and in vitro fertilization failures.

项目摘要人类NLRP7中的母体突变导致妊娠复发性氢化摩尔妊娠与烙印缺陷。其高度同源的基因NLRP2中的母体突变引起多洛克斯在后代中表现为贝克威·韦德曼综合症的印迹障碍（MLID）。两者都是关联的与母体印迹基因的异常DNA甲基化。啮齿动物具有NLRP2基因，但没有NLRP7。我们假设NLRP2可能结合了人类同源物的功能并产生NLRP2突变小鼠研究其孕产妇灭活的机制导致观察到的后代和胎盘的机制异常。我们发现NLRP2蛋白是皮层孕产妇复合物（SCMC）的新成员卵母细胞中的细胞质复合物在植入前胚胎中持续存在，其推测在母亲到孕妇合子过渡和二吻合基因组激活，这是胚胎从依赖转变的过程关于母体的成绩单和蛋白质，以使其自身的转录和翻译。我们发现一个 NLRP2中的母体效应突变会破坏SCMC，导致NLRP2-NULL女性产生越来越小的具有先天缺陷，生长异常和烙印的后代的垃圾。体外培养这些NLRP2无效雌性的胚胎具有更严重的表型，并具有早期的切割阶段停滞。这些第一次将SCMC链接到印迹重编程的数据，并表明NLRP2-NULL小鼠是一个研究这种相互作用机制的优秀模型。他们支持该项目的总体目标表征了母体损失NLRP2，一种新的SCMC蛋白，如何改变后代的印记，以及如何导致它到一系列生殖表型。朝向这个目标，对于特定的目标1，我们将表征细胞和在生殖和植入前胚胎中的发育事件和植入前胚胎的起源烙印表型。对于特定目标2，我们将研究基于的分子机制通过跟进其他有趣的早期观察，孕产妇失活的生殖表型，其中包括NLRP2和DNA-甲基转移酶1（DNMT1）在植入前胚胎中共定位，以及 NLRP2缺陷型卵母细胞改变了基因表达谱。对于特定目标3，我们将在体内表征胚胎丧失NLRP2导致的胚胎和胎盘的后期发育异常。这将增加对孕产妇效应突变引起的生殖疾病的知识。所有表型 DNMT1结合以完全整合的转录组学，甲基组学和分析将补充分子和表型数据。我们预测这项工作将揭示重要的基因组的新原则在配子发生和受精后重新编程，并将阐明SCMC如何影响这一过程。对人类健康的长期利益将包括更好地了解多洛克斯群岛的烙印疾病和某些形式的不育症和体外受精失败。