Kofinas Jason D, Seth-Smith Michelle L, Kramer Yael, Van Daele Jessie, McCulloh David, Wang Fang, Grifo Jamie, Keefe David
Kofinas Fertility Group, 55 Central Park West, New York, NY, 10023, USA.
The Icahn School of Medicine at Mount Sinai, Brooklyn Hospital Center, 121 DeKalb Avenue, Brooklyn, NY, 11201, USA.
J Assist Reprod Genet. 2025 Mar;42(3):753-762. doi: 10.1007/s10815-025-03393-w. Epub 2025 Jan 25.
Induction of meiotic competence is a major goal of the controlled ovarian stimulation used in ART. Do factors intrinsic to the oocyte contribute to oocyte maturation? Deletions in mtDNA accumulate in long-lived post mitotic tissues and are found in human oocytes. If oogenesis cleanses the germline of deleterious deletions in mtDNA, meiotically competent oocytes should contain lower levels of mtDNA deletions vs. meiotically arrested oocytes. We tested this hypothesis using a novel PCR assay for a deletion ratio in human oocytes derived from IVF.
A real-time PCR assay was developed to measure total mtDNA copy number (mtDNA) and mtDNA harboring the 5 Kb "common deletion" to enable calculation of the mtDNA deletion ratio (mtDNA) in 143 cultured oocytes. Kruskal-Wallis test was carried out to compare the total mtDNA and the mtDNA among oocytes which matured to metaphase II (MII) vs. oocytes arrested at GV or metaphase I (MI).
51.75% of oocytes reached MII, and 17% remained at MI. Mean mtDNADR in GV, MI and MII oocytes were 27.87%, 31.88% and 20.05%, respectively. The difference in deletion ratios between GV and MII and between MI and MII stages was statistically significant p < 0.001 and p = 0.034, respectively. Additionally, patient age was found to be positively correlated with time to Polar body extrusion (- 0.278 Pearson correlation).
Oocytes with impaired meiotic maturation contain an increased load of mtDNA deletions. This is the first report of an association between the mtDNA deletion ratio and human oocyte maturation in vitro.
诱导减数分裂能力是辅助生殖技术中控制性卵巢刺激的主要目标。卵母细胞的内在因素是否有助于卵母细胞成熟？线粒体DNA（mtDNA）缺失在有丝分裂后长寿组织中积累，并在人类卵母细胞中发现。如果卵子发生过程能清除mtDNA中有害缺失的种系，那么减数分裂能力正常的卵母细胞与减数分裂停滞的卵母细胞相比，应含有较低水平的mtDNA缺失。我们使用一种新型PCR检测方法来检测体外受精（IVF）获得的人类卵母细胞中的缺失率，以验证这一假设。
开发了一种实时PCR检测方法，用于测量143个培养卵母细胞中的总mtDNA拷贝数（mtDNA）和携带5 kb“常见缺失”的mtDNA，以计算mtDNA缺失率（mtDNA）。采用Kruskal-Wallis检验比较成熟至中期II（MII）的卵母细胞与停滞在GV期或中期I（MI）的卵母细胞之间的总mtDNA和mtDNA。
51.75%的卵母细胞达到MII期，17%的卵母细胞停留在MI期。GV期、MI期和MII期卵母细胞的平均mtDNADR分别为27.87%、31.88%和20.05%。GV期与MII期以及MI期与MII期之间的缺失率差异具有统计学意义，p分别<0.001和p = 0.034。此外，发现患者年龄与极体排出时间呈正相关（Pearson相关系数为-0.278）。
减数分裂成熟受损的卵母细胞中mtDNA缺失负荷增加。这是关于mtDNA缺失率与人类卵母细胞体外成熟之间关联的首次报道。
