SummaryHuman embryos generated in vitro have a high incidence of chromosomal abnormalities that negatively affect pregnancy rate. Embryos generated in vitro secrete extracellular vesicles (EVs) into the culture medium that could be used potentially as indicators of embryo competence. This research aimed to evaluate the concentration and size of EVs and their gDNA content as an indicator of developmental competence in human embryos. Human embryos generated by intracytoplasmic sperm injection (ICSI) were classified morphologically as of either TOP, FAIR or POOR quality. Culture medium and developmentally arrested embryos (which were not able to be used for embryo transfer) were collected. Microvesicles, exosomes (MV/Exo) and apoptotic bodies (ABs) were isolated from culture medium. Nanoparticle tracking analysis (NTA) and array comparative genomic hybridization (aCGH) analysis were performed to evaluate EVs and their gDNA content. From NTA, the diameter (mean) of MVs/Exo from TOP quality embryos was higher (112.17 nm) compared with that of FAIR (108.02) and POOR quality embryos (102.78 nm) (P < 0.05). aCGH analysis indicated that MVs/Exo and ABs carried gDNA with the presence of 23 chromosome pairs. However, when arrested embryos were compared with their respective MVs/Exo and ABs, the latter had an increased rate of chromosomal abnormalities (24.9%) compared with embryos (8.7%) (P < 0.05). In conclusion, the size of EVs from culture medium might be an alternative for evaluating competence of human embryos, however more studies are needed to validate the use of gDNA from EVs as an indicator of embryo competence.

中文翻译：

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评估培养基中的细胞外囊泡和 gDNA 作为人类胚胎发育能力的可能指标

总结人类胚胎产生体外染色体异常的发生率很高，对怀孕率有负面影响。产生的胚胎体外将细胞外囊泡 (EVs) 分泌到培养基中，可潜在地用作胚胎能力的指标。本研究旨在评估 EV 的浓度和大小及其 gDNA 含量，作为人类胚胎发育能力的指标。通过胞浆内单精子注射 (ICSI) 产生的人类胚胎在形态学上被分类为 TOP、FAIR 或 POOR 质量。收集培养基和发育停滞的胚胎（不能用于胚胎移植）。从培养基中分离出微泡、外泌体 (MV/Exo) 和凋亡小体 (AB)。进行了纳米粒子跟踪分析 (NTA) 和阵列比较基因组杂交 (aCGH) 分析以评估 EV 及其 gDNA 含量。来自 NTA，磷< 0.05)。aCGH 分析表明 MVs/Exo 和 ABs 携带有 23 对染色体的 gDNA。然而，当将停滞的胚胎与其各自的 MVs/Exo 和 ABs 进行比较时，与胚胎 (8.7%) 相比，后者的染色体异常率 (24.9%) 增加。磷< 0.05)。总之，来自培养基的 EV 的大小可能是评估人类胚胎能力的替代方法，但是需要更多的研究来验证使用来自 EV 的 gDNA 作为胚胎能力的指标。