Molecular Mechanisms of Meiotic Maturation in Drosophila

果蝇减数分裂成熟的分子机制

基本信息

批准号：
8288746
负责人：
Daniela Drummond-Barbosa
金额：
$ 32.47万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-05-01 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8288746
关键词：
Accounting Address Affect Animal Model Binding Biochemical Cell Cycle Cell Cycle Proteins Cell Cycle Regulation Cell Division Process Cellular biology Chromosome Deletion Chromosome Segregation Complement Complex Congenital Abnormality Contraceptive Agents Coupled Cues Cyst Data Defect Development Drosophila genus Drosophila melanogaster Event Failure Female Fertilization in Vitro Funding Genes Genetic Germ Cells Growth Haploidy Heterozygote Hormonal Human In Vitro Infertility Knowledge Lead Meiosis Meiotic Prophase I Metaphase Methodology Molecular Molecular Genetics Molecular Mechanisms of Action Mus Mutation Oocytes Organism Ovarian Ovulation Pattern Phenotype Process Prophase Proteins Research Role Spontaneous abortion Sterility System Testing Time Ubiquitin Specific Protease 8 Ubiquitination Woman Work Yeasts anaphase-promoting complex base blastomere structure endosulfine expression cloning in vivo mutant oocyte maturation protein function public health relevance tool ubiquitin-protein ligase yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): Meiosis is a fundamental process that is coupled to gamete development. Oocytes arrest in prophase of the first meiotic division to allow for growth. Release from prophase I occurs during meiotic maturation, but the molecular mechanisms regulating this process are incompletely understood. Meiotic maturation defects can result in infertility or in inaccurate segregation of chromosomes, leading to miscarriages and/or birth defects. The fruitfly Drosophila melanogaster offers sophisticated genetic and molecular tools, and a well described ovarian cell biology, making it a powerful system to investigate the control of meiotic maturation. Drosophila oocytes enter meiosis shortly after germline cyst formation and arrest in prophase I during most of their development. After meiotic maturation, oocytes arrest again in metaphase I until ovulation. In the prior funding period, we demonstrated that 1-Endosulfine (Endos) is required for meiotic maturation. Our data suggest that Endos promotes the stability of the cell cycle regulators CyclinA, Polo and Twine/Cdc25 (all known to be targets of the Anaphase Promoting Complex, or APC), and that it also has a separate role via inhibition of the E3 ubiquitin ligase Elgi to promote meiotic maturation. Expression of ENSA, the human 1- endosulfine, rescues the endos meiotic defect, and 1-endosulfine is expressed in mouse oocytes, suggesting conservation of the meiotic function of 1-endosulfine. Our overarching hypothesis is that Endos is a central regulator of meiotic maturation via two mechanisms: it inhibits the activity of the APC to allow the accumulation of key cell cycle regulators, and it antagonizes the ubiquitination of Elgi targets. We will test this hypothesis through the following specific aims: 1) to determine if Endos is a negative regulator of the APC; 2) to determine how the E3 ubiquitin ligase Elgi regulates meiotic maturation downstream of Endos; and 3) to elucidate the molecular mechanism of action of Endos. Elucidation of the molecular mechanisms of meiotic maturation could potentially lead to therapies to address this cause of infertility, as well as to new contraceptives. Furthermore, this knowledge could also lead to technological strategies for in vitro maturation of human oocytes to complement current in vitro fertilization methodology. PUBLIC HEALTH RELEVANCE: Failure of the oocyte to undergo meiotic maturation leads to infertility. Our prior work has identified Endos as a major regulator of meiotic maturation, and we propose to use powerful research tools in fruitflies to understand the function of this protein. Our studies could potentially lead to additional therapies to address infertility, as well as to technological strategies to complement current in vitro fertilization methodology.

描述（由申请人提供）：减数分裂是与配子发育相关的基本过程。卵母细胞在第一次减数分裂前期停滞以允许生长。前期 I 的释放发生在减数分裂成熟期间，但调节该过程的分子机制尚不完全清楚。减数分裂成熟缺陷可能导致不孕或染色体分离不准确，从而导致流产和/或出生缺陷。果蝇果蝇提供了复杂的遗传和分子工具，以及详细描述的卵巢细胞生物学，使其成为研究减数分裂成熟控制的强大系统。果蝇卵母细胞在种系包囊形成后不久进入减数分裂，并在其大部分发育过程中停滞在前期 I。减数分裂成熟后，卵母细胞再次停滞在中期 I，直到排卵。在之前的资助期间，我们证明了减数分裂成熟需要 1-Endosulfine (Endos)。我们的数据表明，Endos 促进细胞周期调节因子 CyclinA、Polo 和 Twine/Cdc25（均已知是后期促进复合物 (APC) 的目标）的稳定性，并且它还通过抑制 E3 泛素发挥单独的作用连接酶Elgi促进减数分裂成熟。 ENSA（人 1-endosulfine）的表达可挽救内切减数分裂缺陷，并且 1-endosulfine 在小鼠卵母细胞中表达，表明 1-endosulfine 减数分裂功能得到保护。我们的总体假设是，Endos 通过两种机制成为减数分裂成熟的中央调节因子：它抑制 APC 的活性以允许关键细胞周期调节因子的积累，并且它拮抗 Elgi 靶标的泛素化。我们将通过以下具体目标来检验这一假设：1）确定 Endos 是否是 APC 的负调节因子； 2) 确定E3泛素连接酶Elgi如何调节Endos下游的减数分裂成熟； 3）阐明Endos作用的分子机制。阐明减数分裂成熟的分子机制可能会带来解决不孕不育原因的治疗方法，以及新的避孕药具。此外，这些知识还可能导致人类卵母细胞体外成熟的技术策略，以补充当前的体外受精方法。公众健康相关性：卵母细胞未能经历减数分裂成熟会导致不孕。我们之前的工作已确定 Endos 是减数分裂成熟的主要调节因子，我们建议在果蝇中使用强大的研究工具来了解这种蛋白质的功能。我们的研究可能会带来解决不孕症的额外疗法，以及补充当前体外受精方法的技术策略。