Investigating Pre-Implantation Chromosomal Instability in Assisted Reproduction

研究辅助生殖中植入前染色体不稳定性

• 批准号: 9321448
• 负责人: Shawn L. Chavez
• 金额: $ 36.31万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-24 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9321448
• 关键词: Address; Aneuploidy; Arts; Behavior; Bioinformatics; Biopsy; Birth Rate; Cell Death; Cells; Chromosomal Instability; Chromosomal Stability; Chromosome abnormality; Chromosomes; Complex; Conceptions; Couples; DNA; DNA Microarray Chip; Data; Development; Embryo; Embryo Transfer; Embryonic Development; Encapsulated; Event; Excision; Exhibits; Female; Fertilization failure; Fertilization in Vitro; Frequencies; Generations; Genes; Genetic Materials; Genomics; Human; Image; In Vitro; Incidence; Individual; Infertility; Inherited; Link; Live Birth; Macaca mulatta; Malignant Neoplasms; Maternal Age; Measures; Meiosis; Microsatellite Repeats; Mitosis; Mitotic; Modeling; Monitor; Mosaicism; Mus; Oocytes; Pregnancy; Primates; Principal Investigator; Process; Reproductive Physiology; Resolution; Risk; Source; Study models; Techniques; Therapeutic Intervention; Time; Translating; Translations; Woman; Work; assisted reproduction; base; blastomere structure; embryo stage 2; genetic analysis; improved; next generation sequencing; nonhuman primate; oocyte maturation; preimplantation; programs; response; segregation; success; time interval; whole genome; zygote

Program Director/Principal Investigator (Last, First, Middle): Chavez, Shawn L. Project Summary/Abstract Since its introduction over 35 years ago, human in vitro fertilization (IVF) has assumed great promise for infertile couples, but success rates have remained only ~30% worldwide for several decades. One of the primary reasons for this is that whole chromosomal abnormalities, or aneuploidy, are incredibly common in cleavage-stage human embryos. Previously, we demonstrated that assessing the time intervals of the first three mitotic divisions in conjunction with a phenomenon called cellular fragmentation, which is frequently observed in human embryos as well as following natural conception, largely distinguishes chromosomally normal and abnormal cleavage-stage human embryos. We also determined that cellular fragments might contain genetic material that likely began as mis-segregated chromosomes were encapsulated into micronuclei during meiosis and/or mitosis. Although cellular fragmentation is closely linked with aneuploidy generation and micronuclei formation, the source of these fragments and their precise chromosomal content is not well defined. In addition, whether embryos from other mammalian species more closely related to humans such as non-human primates have a similar aneuploidy frequency remains unknown and addressing this question is essential for potential translation to early human embryogenesis. Our preliminary data reveals that rhesus cleavage-stage embryos also exhibit a high degree of aneuploidy, fragmentation, and micronucleation as well as similar mitotic timing when compared to human. Given that humans and the rhesus monkey are also highly similar in terms of female reproductive physiology and fundamental aspects of early embryogenesis, we propose to investigate aneuploidy and the fate of mis-segregated chromosomes in rhesus embryos to model human pre-implantation development. By applying whole-genome next-generation sequencing (NGS) for comprehensive chromosomal assessment, we will first determine the frequency of aneuploidy and sub- chromosomal errors during meiosis in individual mature rhesus oocytes and zygotes and potential correction upon chromosome-induced polar body extrusion. Using a combination of NGS and non-invasive time-lapse imaging to monitor early cleavage divisions and cellular fragmentation dynamics, we will then evaluate the incidence of mitotic chromosomal mis-segregation up to the ~8-cell stage and reconstruct all whole and sub- chromosomal errors in each rhesus embryo by analyzing the genetic content of both single cells and fragments. Lastly, we will assess the potential contribution of meiotic chromosomal mis-segregation to mitotic errors and subsequent development by performing polar body biopsy on zygotes, allowing the embryo to proceed until the ~8-cell stage, and distinguishing meiotic versus mitotic errors based on chromosomal mosaicism, fragmentation timing, and microsatellite analysis. This work will greatly contribute to our knowledge of normal primate embryogenesis with additional implications for translational application to human infertility and IVF treatment. OMB No. 0925-0001/0002 (Rev. 08/12 Approved Through 8/31/2015) Page Continuation Format Page

方案主任/首席调查员(最后、第一、中间)：查韦斯，肖恩·L。 项目摘要/摘要 自35年前引入以来，人类体外受精(IVF)已经被认为是 不孕不育的夫妇，但几十年来，全球的成功率仅保持在30%左右。其中一个 主要原因是整个染色体异常，或非整倍体，在 卵裂期的人类胚胎。在此之前，我们演示了评估第一个 三次有丝分裂伴随着一种称为细胞碎裂的现象，这种现象通常是 在人类胚胎和自然受孕后观察到的，在染色体上有很大的区别 正常和异常的卵裂期人类胚胎。我们还确定了细胞碎片可能 含有遗传物质，最初可能是错误分离的染色体被包裹到微核中 在减数分裂和/或有丝分裂期间。尽管细胞碎裂与非整倍体的产生和 微核的形成，这些片段的来源及其精确的染色体含量并不是很好 已定义。此外，来自其他与人类关系更密切的哺乳动物物种的胚胎是否 非人灵长类动物有类似的非整倍体频率仍不清楚，解决这个问题是 对人类早期胚胎发育的潜在转化至关重要。我们的初步数据显示，恒河猴 卵裂期胚胎也表现出高度的非整倍体、碎片化和微核。 与人类相比，有丝分裂的时间相似。鉴于人类和恒河猴也高度 在女性生殖生理和早期胚胎发育的基本方面相似，我们 建议研究猕猴胚胎的非整倍体和错误分离的染色体的命运以建立 人类植入前发育。通过应用全基因组下一代测序(NGS)来 综合染色体检测，我们将首先确定非整倍体和亚倍体的频率 恒河猴个体成熟卵母细胞和受精卵减数分裂过程中的染色体错误及可能的纠正 在染色体诱导的极体挤出时。结合使用NGS和非侵入性延时 为了监测早期卵裂分裂和细胞碎裂动力学，我们将评估 直到~8细胞期有丝分裂染色体错误分离的发生率并重建所有完整和亚 每个恒河猴胚胎中的染色体错误通过分析单细胞和 碎片。最后，我们将评估减数分裂染色体错误分离对有丝分裂的潜在贡献。 通过对受精卵进行极体活检，使胚胎能够 继续进行到~8细胞期，并根据染色体区分减数分裂和有丝分裂错误 嵌合体、片段计时和微卫星分析。这项工作将对我们的知识有很大贡献 正常灵长类胚胎发生及其在翻译应用于人类不孕不育方面的其他意义 和试管受精治疗。 OMB编号0925-0001/0002(08/12版批准至2015年8月31日)页面续格式页面