Kochan Joanna, Nowak Agnieszka, Kij Barbara, Prochowska Sylwia, Niżański Wojciech
Department of Animal Reproduction, Anatomy and Genomics, University of Agriculture, Mickiewicza 24/28, 30-059 Krakow, Poland.
Department of Reproduction and Clinic of Farm Animals, University of Environmental Science, Grundwaldzki Square 49, 50-357 Wroclaw, Poland.
Animals (Basel). 2021 Mar 9;11(3):748. doi: 10.3390/ani11030748.
The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest proportion of embryos (46%) cleaving between 21 and 24 hpi. The timing of the first cleavage significantly affected further embryo development, with the highest development occurring in embryos that cleaved at 21-22 hpi. Embryos that cleaved very early (17-18 hpi) developed poorly to the blastocyst stage (2%) and none of the embryos that cleaved later than 27 hpi were able to reach the blastocyst stage. Morphological defects were observed in 48% of the embryos. There were no statistically significant differences between the timing intervals of the first cleavage division and the frequency of morphological defects in embryos. Multiple (MUL) morphological defects were detected in more than half (56%) of the abnormal embryos. The most frequent single morphological defects were cytoplasmic fragmentation (FR) (8%) and blastomere asymmetry (AS) (6%). Direct cleavage (DC) from 1-3 or 3-5 blastomeres, reverse cleavage (RC) and vacuoles were rarely observed (2-3%). The timing of blastocyst cavity formation is a very good indicator of embryo quality. In our study, blastocyst cavity formation occurred between 127-167 hpi, with the highest frequency of hatching observed in blastocysts that cavitated between 142-150 hpi. Blastocysts in which cavitation began after 161 h did not hatch. In conclusion, the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.
本研究的目的是使用延时系统分析猫胚胎的形态动力学参数。体外成熟的卵母细胞经体外受精（IVF）后，在延时系统（Primo Vision，瑞典哥德堡）中进行体外培养。胚胎的第一次细胞分裂发生在授精后17小时（hpi）至38小时之间，其中在21至24小时hpi之间分裂的胚胎比例最高（46%）。第一次分裂的时间显著影响胚胎的进一步发育，在21至22小时hpi分裂的胚胎发育最好。极早期（17至18小时hpi）分裂的胚胎发育至囊胚阶段的情况较差（2%），而在27小时hpi后分裂的胚胎无一能够发育至囊胚阶段。48%的胚胎观察到形态学缺陷。胚胎第一次分裂的时间间隔与形态学缺陷的频率之间无统计学显著差异。超过一半（56%）的异常胚胎检测到多种（MUL）形态学缺陷。最常见的单一形态学缺陷是细胞质碎片（FR）（8%）和卵裂球不对称（AS）（6%）。很少观察到从1至3个或3至5个卵裂球直接分裂（DC）、反向分裂（RC）和空泡（2至3%）。囊胚腔形成的时间是胚胎质量的一个很好指标。在我们的研究中，囊胚腔形成发生在授精后127至167小时之间，在142至150小时之间形成囊胚腔的囊胚孵化频率最高。在161小时后开始形成囊胚腔的囊胚未孵化。总之，第一次和第二次分裂的时间、囊胚腔形成的时间以及形态学异常都可以作为猫胚胎体外发育的早期和非侵入性指标。
