GENDER BIAS IN MAMMALIAN DNA REPLICATION DURING DEVELOPMENT

发育过程中哺乳动物 DNA 复制的性别偏见

• 批准号: 9407791
• 负责人: John C Schimenti
• 金额: $ 31.33万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-05 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9407791
• 关键词: Ablation; Address; Alleles; Androgen Receptor; Animals; Anti-inflammatory; Basic Science; Biological Process; Birth; Cells; Cessation of life; Characteristics; Chemicals; Cultured Cells; DNA Biochemistry; DNA Damage; DNA biosynthesis; Data; Defect; Development; Disease; Embryo; Embryo Transfer; Embryonic Development; Environment; Event; Female; Fibroblasts; Fostering; Gender; Genes; Genetic; Genomic Instability; Genotype; Glucocorticoids; Goals; Heterozygote; Human; Hypersensitivity; Ibuprofen; Inflammation; Inflammatory; Inflammatory Response; Inherited; Interleukin-10; Interleukin-6; Intervention; Lead; Licensing; MCM2 gene; Maintenance; Malignant Neoplasms; Mammals; Measures; Mediating; Molecular Analysis; Mothers; Mus; Non-Steroidal Anti-Inflammatory Agents; Organism; Outcome; Partner in relationship; Pathway interactions; Pregnancy; Process; Proteins; Replication Licensing; Replication Origin; Research; Risk; Secondary to; Sex Bias; Spontaneous abortion; Stress; Testing; Testosterone; Tissues; Transgenes; X Inactivation; adverse pregnancy outcome; cytokine; experimental study; fetal; gender difference; helicase; inflammatory marker; male; mutant; novel; pregnant; prevent; response; risk variant; senescence; sex; sex determination; sexual dimorphism; zygote

Project Abstract DNA replication is the most essential event in the propagation of a species. Defects in this process can cause diseases including birth (developmental) defects and cancer. When DNA replication is compromised genetically or environmentally, a state known as “replication stress” (RESS) occurs that can lead to the aforementioned deleterious outcomes. Extensive basic research on the biochemistry of DNA replication has been conducted in single celled organisms and cultured cells, without regard for potential gender differences that may exist in higher organisms such as mammals. The goal of this project is to understand how the universal process of DNA replication is subject to dramatic sexual dimorphism in mammalian embryogenesis. Preliminary studies found that female mouse embryos were dramatically more prone to lethality when levels of the MCM2-7 (Minichromosome maintenance 2,3,4,5,6,7) DNA replication licensing and helicase proteins were genetically reduced and the helicase destabilized. Subsequent studies revealed that the female-biased lethality began occurring immediately after sex determination, and was not related to defects in X-inactivation.Transgene-mediated conversion of female embryos to males or testosterone administration reversed the gender-biased lethality, indicating that the phenomenon is related to secondary sexual characteristics. Further experiments suggested that testosterone enabled female embryo rescue by virtue of its anti-inflammatory activity, a possibility supported by the observation that ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), also rescued MCM-deficient female embryos. This project seeks to elucidate the cellular and mechanistic basis of this novel example of mammalian sexual dimorphism. Aim 1 will test whether female- biased embryo lethality in MCM-depleted animals is due to gender differences in DNA replication per se, or differential sensitivity to intrinsic RESS. Aim 2 will test the hypothesis that female embryo hypersensitivity is related to RESS-induced inflammation, while males embryos are protected by the anti-inflammatory activity of testosterone they produce in high levels following sex determination. Aim 3 will explore the basis of preliminary data showing that a key contributing factor in the sex bias phenomenon is the maternal environment; only dams with intrinsic RESS preferentially lost female embryos. This will be accomplished transferring at-risk genotypes of zygotes into foster mothers that are genotypically wild-type, MCM-deficient, or deficient for the anti-inflammatory cytokine IL-10. Overall, these studies will can impact our understanding of the relationships between RESS, inflammation, and adverse pregnancy outcomes related to maternal and/or fetal inflammatory responses that are genetically or environmentally induced.

项目摘要 DNA复制是物种传播中最重要的事件。在此过程中的缺陷可以 引起包括出生（发育）缺陷和癌症在内的疾病。当DNA复制是 一般或环境中受到妥协，被称为“复制应力”（RESS）的状态发生了 可能导致删除结果的原因。关于生物化学的广泛基础研究 DNA复制已在单细胞生物和培养细胞中进行，而无需考虑 在哺乳动物等较高生物体中可能存在的潜在性别差异。目标的目标 项目是要了解DNA复制的普遍过程如何受到戏剧性性的影响 哺乳动物胚胎发生中的二态性。初步研究发现雌性小鼠胚胎是 当MCM2-7的水平（微型胶质体维护）水平时，龙更容易致死性 2,3,4,5,6,7）DNA复制许可和解旋酶蛋白被遗传降低，而解旋酶 不稳定。随后的研究表明，女性偏见的致死性立即开始 性别确定后，与X灭活中的缺陷无关。转变介导的转换 男性或睾丸激素给药的雌性胚胎扭转了性别偏见的杀伤力， 表明该现象与继发性特征有关。进一步的实验 建议睾丸激素通过其抗炎活性来启用雌性胚胎营救 观察到的可能性是布洛芬，一种非甾体类抗炎药（NSAID）， 还检索了MCM缺陷型雌性胚胎。该项目旨在阐明细胞和 这个新颖的哺乳动物性二态性例子的机械基础。 AIM 1将测试是否 雌性偏见的胚胎杀伤力在耗尽MCM的动物中是由于DNA的性别差异引起的 复制本身或对内在的RES的差异敏感性。 AIM 2将检验女性的假设 胚胎超敏反应与RESS诱导的注射有关，而雄性胚胎受到保护 通过性别确定后，通过睾丸激素的抗炎活性，它们在高水平中产生。 AIM 3将探索初步数据的基础，表明性别偏见的关键因素 现象是母校的环境；只有内在的Ress的大坝优先失去了女性 胚胎。这将是通过将Zygotes的高风险基因型转移到寄养母亲的 是基因型野生型，MCM缺乏症或抗炎细胞因子IL-10的缺陷。全面的， 这些研究将影响我们对RES，炎症和 与母校和/或胎儿炎症反应有关的不良怀孕结果 遗传或环境诱导。