Defects in Mitochondria Impacting Primate Oocyte Quality

描述（由申请方提供）：本研究的总体目标是使用恒河猴作为最适合人类的实验模型，检查卵母细胞中不同线粒体特征作为卵母细胞健康的标志物或预测因子的功能意义。将采用3种方法：（i）使用多光子显微镜作为提供4维（4D）信息的非侵入性分析工具，在体外受精之前、期间和之后评估卵母细胞中的线粒体定位概况;（ii）通过测量不同发育阶段的ATP水平来确定卵母细胞和胚胎中线粒体的功能活性;和（iii）评价来自人的卵母细胞和来自年轻和年老猴的卵母细胞和胚胎中的线粒体突变，以及评价组织和细胞中的体细胞mtDNA突变作为生殖衰老的基线标记。该研究将确定所有这3种线粒体特征指标之间的相关程度，以及与恒河猴体外受精后胚胎发育的相关程度。如果发现良好的相关性，这将表明发育不全的卵母细胞典型的线粒体的定位特征和活性代表了一种病理状态。因此，“正常”定位谱可用作卵母细胞能力的非侵入性标记或预测物，使得仅选择最有活力的胚胎用于胚胎移植。然后，可以在其他临床研究中评估这些信息，以应用于人类卵母细胞和胚胎。这项研究还将确定mtDNA缺陷是否表现为恒河猴线粒体定位谱紊乱、线粒体活性改变和/或卵母细胞发育能力受损。这项研究中获得的信息也将提高我们对线粒体在灵长类卵母细胞和胚胎生物学中的作用以及随着年龄的增长女性生殖能力逐渐丧失的理解。

DESCRIPTION (provided by applicant): The overall goal of this study is to examine the functional significance of different mitochondrial characteristics in oocytes as markers or predictors of oocyte health, using the rhesus monkey as the most appropriate experimental model for humans. 3 approaches will be used: (i) assessment of mitochondrial localization profiles in oocytes before, during and after fertilization in vitro using multiphoton microscopy as a non-invasive analytical tool that provides 4-dimensional (4D) information; (ii) determining the functional activity of mitochondria in oocytes and embryos by measuring ATP levels at different stages of development; and (iii) evaluation of mitochondrial mutations in oocytes from humans and oocytes and embryos from young and old monkeys, as well as the evaluation of somatic mtDNA mutations in tissues and cells as a baseline marker for reproductive senescence. The study will determine the extent to which all 3 of these measures of mitochondrial characteristics are related to 1 another, and to embryo development subsequent to fertilization in vitro, in rhesus monkeys. If good correlations are found, this will indicate that the localization profiles and activity of mitochondria typical of developmentally incompetent oocytes represent a pathological condition. Thus, the "normal" localization profiles could be used as a non-invasive marker or predictor of oocyte competence so that only the most viable embryos are selected for embryo transfer. This information could then be evaluated in other clinical studies for application to human oocytes and embryos. This study will also determine if mtDNA defects are manifested as disturbed mitochondrial localization profiles, altered mitochondrial activity, and/or compromised oocyte developmental competence in rhesus monkeys. Information gained in this study will also improve our understanding of the role of mitochondria in primate oocyte and embryo biology, and in the progressive loss of female reproductive capacity with age.