Investigating conserved mechanisms that orchestrate the prophase to metaphase transition during meiosis I

研究减数分裂 I 期间协调前期到中期转变的保守机制

• 批准号: 10534113
• 负责人: Ian Wolff
• 金额: $ 6.76万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10534113
• 关键词: Acute; Adaptor Signaling Protein; Address; Aneuploidy; Animal Model; Animals; Auxins; Binding Proteins; Biochemical; Biochemistry; Biological Assay; CDC2 gene; CUL1 gene; Caenorhabditis elegans; Cell Cycle; Cell Cycle Progression; Cell Nucleus; Cells; Chromatin; Chromosome Pairing; Chromosome Segregation; Chromosomes; Complex; Conceptions; Coupled; Cullin Proteins; Cyclin B; Cyclins; Data; Defect; Development; Development Plans; Diploidy; Embryo; Ensure; Enzymes; Eukaryota; Event; F Box Domain; Family; Female; Gametogenesis; Genetic; Genetic Crossing Over; Genetic Materials; Germ Cells; Germ Lines; Haploidy; House mice; Human; Individual; Investigation; Knockout Mice; Knowledge; Laboratories; Laboratory mice; Lead; Licensing; Licensing Factor; Life; Lighting; Maturation-Promoting Factor; Mediating; Meiosis; Meiotic Prophase I; Metaphase; Microscopy; Mitosis; Mitotic; Modeling; Molecular; Mus; Mutant Strains Mice; Nematoda; Oogenesis; Organism; Orthologous Gene; Phase Transition; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Play; Positioning Attribute; Pregnancy Complications; Process; Prophase; Proteins; Publishing; RNA Interference; RNA interference screen; Regulation; Reproduction; Reproductive Biology; Research; Resolution; Role; Signal Transduction; Spermatocytes; System; Techniques; Testing; Testis; Training; Ubiquitin-Conjugating Enzymes; Ubiquitination; Universities; Veterinary Medicine; Work; career development; college; competence factor; egg; experimental study; genetic information; inhibitor; male; member; mutant; precursor cell; prevent; sperm cell; three dimensional structure; ubiquitin-protein ligase

Sexually reproducing organisms generate gametes through meiosis, the process by which the genetic material of the cell is halved to form a haploid sperm or egg. Although essential for all animal life, meiosis is strikingly error-prone, with an estimated 5-25% of all human conceptions resulting in an aneuploid embryo, often leading to severe developmental defects and pregnancy complications that effect millions of individuals every year. Therefore, it is critical to investigate the core molecular mechanisms that define progression through meiosis to further understand what checkpoints may exist to sense errors. This proposal investigates the control of meiotic progression using two powerful meiotic models, the lab mouse Mus musculus and the nematode Caenorhabditis elegans. Meiosis I proceeds through pairing, synapsis, and crossing over (CO) of homologous chromosomes during prophase, and only once these events have occurred correctly can homologs align appropriately on the meiotic spindle and then segregate equally at the first meiotic division. However, it is unclear how successful CO formation is sensed by cell cycle machinery to progress meiosis into M-phase. Proper CO formation requires orthologous cyclin-like domain containing proteins CNTD1, in mouse spermatocytes, and COSA-1, in C. elegans oogenesis. Interestingly, CNTD1 interacts with CDC34, a ubiquitin E2 conjugating enzyme that acts with the Skp1-Cullin-F-Box (SCF) family of E3 ubiquitin ligases. A known target of CDC34 in mitotic systems is the cell cycle M-phase inhibitor, WEE1. In CNTD1 knockout mouse spermatocytes, CDC34 is absent from nuclei and WEE1 persists aberrantly through until the end of meiotic prophase, suggesting a role for CNTD1-promoted crossover maturation in WEE1 degradation and resulting progression into M-phase. This leads to the hypothesis that progression from meiotic prophase I to M-phase I is licensed through direct WEE1 ubiquitination by SCFCDC34 in a crossover-dependent manner that is conserved across eukaryotes. This proposal presents two specific aims: 1) Is SCFCDC34-mediated ubiquitination of WEE1 critical for progression from meiotic prophase I to M-phase I? WEE1 ubiquitination and WEE1/CDC34 chromatin localization will be directly tested in both wild type and crossover deficient mutant mice. An assay will be developed to directly visualize the germ line abundance of the WEE1 ortholog in C. elegans, WEE-1.3, to test the role of WEE-1.3 in C. elegans meiotic progression. 2) What is the biochemical mechanism of SCFCDC34 mediated WEE1 ubiquitination? The molecular components of the SCFCDC34 complex will be elucidated in mouse spermatocytes through mutant analysis of putative complex members, and in C. elegans through a RNAi screen. This work will be performed in the lab of Dr. Paula Cohen in the Cornell University College of Veterinary Medicine, providing extensive training in mammalian reproductive biology, specifically in the early meiotic events during gametogenesis. This research strategy coupled with the applicant’s training and career development plans will provide a unique approach towards investigation of meiosis through using complementary model organisms.

有性生殖的生物体通过减数分裂产生配子，遗传物质通过减数分裂产生配子