Genetics of Meiosis and Recombination in Mice

小鼠减数分裂和重组的遗传学

基本信息

批准号：
8579452
负责人：
John C Schimenti
金额：
$ 31.41万
依托单位：
CORNELL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-02-01 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8579452
关键词：
Ablation Address Age Aneuploidy Apoptosis Behavior Biochemical Biological Preservation CHEK2 gene CHES1 gene Cancer Patient Cell division Cells Cessation of life Chromosome Segregation Chromosome abnormality Chromosomes Congenital Abnormality DNA Damage DNA Double Strand Break DNA Repair Pathway DNA damage checkpoint Data Defect Development Diagnosis Double Strand Break Repair Face Failure Female Fertility Gene Mutation Genetic Genetic Identity Genetic Recombination Genome Genomics Germ Cells Health Human Knockout Mice Knowledge Lead Malignant Neoplasms Mammals Mediating Meiosis Meiotic Recombination Mitotic Molecular Mus Mutant Strains Mice Mutation Nature Nonhomologous DNA End Joining Oocytes Oogenesis Outcome Pachytene Stage Pathway interactions Pattern Pharmaceutical Preparations Phosphorylation Phosphotransferases Pregnancy Primordial Follicle Process Production Protein Isoforms Proteins Quality Control Radiation Rest Role Safety Seminiferous tubule structure Side Sister Chromatid Spermatocytes Spontaneous abortion Staging Sterility Sum Testing Transactivation Translating Woman assisted reproduction base cancer therapy checkpoint kinase 2 chemotherapy egg genetic analysis genome sequencing high standard in vivo inhibitor/antagonist male offspring paralogous gene programs protective effect public health relevance repaired reproductive research study response sexual dimorphism sperm cell success transcription factor transmission process

项目摘要

DESCRIPTION (provided by applicant): Faithful transmission of the genome through gametes is critical for fertility, health of offspring, and success of the species. Errors in meiosis can lad to aneuploidy, chromosome aberrations, or gene mutations. The vast majority of spontaneous abortions due to aneuploidy are traceable to Meiosis I defects that occur during oogenesis. Although "checkpoint" mechanisms exist to stimulate repair of meiotic errors and eliminate irreparably defective meiocytes, their molecular identities and mechanisms are poorly characterized or unknown in humans or mammals. We have used genetic analyses of mice to identify the key checkpoint responsible for responding to DNA double strand breaks (DSBs) in oocyte meiosis. DSBs are enzymatically induced at the beginning of meiosis in order to stimulate meiotic recombination - a process essential for proper chromosome segregation upon cell division. Failure to repair the DSBs triggers a checkpoint that results in oocyte elimination. We identified checkpoint kinase 2 (CHK2; CHEK2) as an essential component of this response. Startlingly, female mice that are oocyte-deficient from a mutation that disrupts DSB repair can have their fertility restored by concurrent mutation of Chk2, yielding apparently normal offspring. We also found that both programmed and induced DSBs trigger CHK2-dependent phosphorylation of p63 (TRP63) in diplotene oocytes. These and other data establish CHK2 as essential for DNA damage surveillance in female meiosis, and we propose that the DNA damage checkpoint pathway is: ATR>CHK2>p63. However, Chk2 is not essential for elimination of DSB-bearing spermatocytes, indicating sexual dimorphism. This proposal builds on these findings with the following basic and translational objectives: 1) To validate and mechanistically characterize putative upstream (ATR) and downstream (p63) components of the oocyte DNA damage checkpoint using conditionally mutant mice and molecular analyses; 2) Determine the identity of the male DNA damage checkpoint; 3) Determine the fate of DSBs in recombination-defective, rescued oocytes by whole genome sequencing of offspring and genetic analyses of potential alternative DNA repair pathways. This is important for assessing the safety of checkpoint inhibition for reasons of assisted reproduction or fertility preservation in cancer patients; and 4) Determine if CHK2 drug inhibitors can protect oocytes from death due to cancer treatments, and in a manner that doesn't cause birth defect-causing mutations. In sum, this project will elucidate the genetic quality control mechanisms operate in mammalian gametes. Arguably, this is one of the most important processes for the health and success of our species and others.

描述（由申请人提供）：基因组通过配子的忠实传播对于生育能力，后代的健康和物种成功至关重要。减数分裂中的错误可能会导致非整倍性，染色体畸变或基因突变。由于非整倍性引起的绝大多数自发堕胎可追溯到卵子发生过程中发生的减数分裂。尽管存在“检查点”的机制来刺激减数分裂误差并消除不可挽回的细胞细胞，但它们的分子身份和机制在人类或人类或哺乳动物中的特征或未知。我们已经使用了小鼠的遗传分析来识别负责响应卵母细胞减数分裂中DNA双链断裂（DSB）的关键检查点。为了刺激减数分裂重组，DSB是在减数分裂开始时诱导的，这是细胞分裂时正确染色体分离至关重要的过程。无法修复DSB的触发检查点，从而导致消除卵母细胞。我们将检查点激酶2（CHK2; CHEK2）确定为此响应的重要组成部分。令人惊讶的是，从破坏DSB修复的突变中缺乏卵母细胞的雌性小鼠可以通过同时发生的CHK2突变恢复生育能力，从而产生正常后代。我们还发现，p63（TRP63）在外交卵母细胞中触发了编程和诱导的DSB触发CHK2依赖性磷酸化。这些和其他数据将CHK2定为女性减数分裂中的DNA损伤监测至关重要，我们建议DNA损伤检查点途径为：ATR> CHK2> p63。但是，CHK2对于消除含有DSB的精子细胞并不重要，表明性二态性。该提案以以下基本和翻译目标为基础：1）使用有条件的突变小鼠和分子分析来验证和机理表征卵母细胞DNA损伤检查点的假定上游（ATR）和下游（p63）组件； 2）确定雄性DNA损伤检查点的身份； 3）确定DSB在重组缺陷中的命运，通过对后代和潜在替代DNA修复途径的后代和遗传分析的整个基因组测序挽救的卵母细胞的命运。这对于评估癌症患者辅助繁殖或生育能力的原因评估检查点抑制的安全很重要； 4）确定CHK2药物抑制剂是否可以通过癌症治疗引起的卵母细胞免受死亡的死亡，并且不会导致造成源缺陷的突变。总而言之，该项目将阐明在哺乳动物配子中运作的遗传质量控制机制。可以说，这是我们物种和其他物种的健康和成功的最重要过程之一。