Abstract:
In vitro production (IVP) embryos have a reduced quality and poor cryotolerance in comparison to in vivo embryos. This study investigated whether free fatty acid (FFA) conditions, fatty acid free (FAF)- synthetic oviduct fluid (SOF) without or with 25 μM of saturated stearic (C18:0) or unsaturated oleic (C18:1) acid during the first 5 IVP days, relate to quality and cryosurvival of day 8 blastocysts. Apart from the blastocyst scores, both 1) number and size of lipid droplets of fresh blastocysts and 2) total number and apoptotic and necrotic cells, before and after freezing-thawing, were scored by confocal microscopy. Blastocyst rates were significantly lower in the FAF SOF condition in comparison to other groups. Interestingly, blastocysts originating from the C18:1 group, with a significantly higher lipid content, and blastocysts from the FAF SOF group demonstrated a high cryosurvival rate (70.1 and 67.4%, respectively) comparable with in vivo blastocysts (68%), in contrast to the poor cryosurvival of C18:0 exposed embryos (17.6%). In all freeze-thawed embryos the average amount of apoptotic and necrotic cells increased albeit that the C18:0 condition rates were higher (43.2%) when compared to C18:1 (26.0%) and FAF SOF conditions (26.5%). The current data show that FFA administered during early embryonic development significantly affect the cryotolerance of blastocysts.
摘要:
与体内胚胎相比,体外生产(IVP)胚胎的质量降低且低温耐受性差。这项研究调查了游离脂肪酸(FFA)条件是否,无脂肪酸(FAF)-在前5个IVP天期间,不含或含25μM饱和硬脂酸(C18:0)或不饱和油酸(C18:1)的合成输卵管液(SOF),与第8天囊胚的质量和冷冻存活有关。除了胚泡评分,1)新鲜囊胚脂滴的数量和大小,2)总数和凋亡和坏死细胞,在冻融之前和之后,通过共聚焦显微镜进行评分。与其他组相比,FAFSOF条件下的囊胚率明显较低。有趣的是,来自C18:1组的胚泡,具有明显更高的脂质含量,FAFSOF组的囊胚表现出很高的冷冻存活率(70.1%和67.4%,分别)与体内胚泡(68%)相当,与C18:0暴露胚胎(17.6%)的冷冻存活率差相反。在所有冻融胚胎中,凋亡和坏死细胞的平均数量增加,尽管与C18:1(26.0%)和FAFSOF条件(26.5%)相比,C18:0条件的发生率更高(43.2%)。目前的数据显示,在早期胚胎发育期间施用的FFA显著影响胚泡的低温耐受性。