Munakata Yasuhisa, Shirasuna Koumei, Kuwayama Takehito, Iwata Hisataka
Department of Animal Reproduction, Tokyo University of Agriculture, Kanagawa 243-0034, Japan.
J Reprod Dev. 2019 Apr 12;65(2):171-175. doi: 10.1262/jrd.2018-123. Epub 2019 Feb 11.
Follicular fluid contains cell-free DNA (cfDNA), which may serve as a useful biomarker of oocyte ability. The present study evaluates whether nuclear and mitochondrial cfDNAs in conditioned oocyte growth medium determine the quality of oocytes cultured in vitro. Oocyte and granulosa cell complexes (OGCs) derived from early antral follicles of gilt ovaries were cultured for 14 days and the amount of cfDNA and lactate concentration in the conditioned culture medium were measured and compared to evaluate oocyte maturation ability. The amount of nuclear cfDNA, but not mitochondrial cfDNA, strongly correlated with the number of dead cells in OGCs. Furthermore, low mitochondrial cfDNA content and high lactate concentration in the medium was associated with high maturation ability of oocytes cultured in vitro. In conclusion, the amounts of nuclear and mitochondrial cfDNAs differentially reflect the conditions of OGCs, and low mitochondrial cfDNA, low glucose content, and high lactate concentration in the medium are associated with the proper maturation of oocytes.
卵泡液中含有游离DNA（cfDNA），其可能作为卵母细胞能力的一种有用生物标志物。本研究评估了条件性卵母细胞生长培养基中的核cfDNA和线粒体cfDNA是否能决定体外培养的卵母细胞质量。对来自后备母猪卵巢早期窦状卵泡的卵母细胞和颗粒细胞复合体（OGC）进行14天培养，并测量条件性培养基中cfDNA的量和乳酸浓度，进行比较以评估卵母细胞成熟能力。核cfDNA的量与OGC中死亡细胞的数量密切相关，而线粒体cfDNA则不然。此外，培养基中线粒体cfDNA含量低和乳酸浓度高与体外培养的卵母细胞高成熟能力相关。总之，核cfDNA和线粒体cfDNA的量差异反映了OGC的状况，培养基中线粒体cfDNA含量低以及葡萄糖含量低和乳酸浓度高与卵母细胞的正常成熟有关。
