Hao Yanhong, Lai Liangxue, Mao Jiude, Im Gi-Sun, Bonk Aaron, Prather Randall S
Department of Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
Biol Reprod. 2004 Jun;70(6):1644-9. doi: 10.1095/biolreprod.103.026005. Epub 2004 Feb 6.
Parthenogenesis (PA) of the oocyte is essential to a number of oocyte- or embryo-related technologies such as intracytoplasmic sperm injection and cloning by nuclear transfer. This study investigated the onset and frequency of apoptosis in PA- porcine embryos and the morphological changes that conform to the general criteria of apoptotic cell death by using a terminal deoxynucleatidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) assay. PA embryos had a higher degree of apoptotic cell death during in vitro culture, a lower cleavage rate (45% vs. 71%), and a lower development rate to the blastocyst stage (16% vs. 29%), relative to in vitro fertilization (IVF). The earliest positive TUNEL signal in the PA embryos was detected on Day 6, 1 day later than that in IVF embryos. Apoptosis in PA embryos increased from 15% of the embryos on Day 6 to 29% on Day 8. The mean level of apoptosis of the PA embryos was statistically higher than that of IVF embryos, except on Day 5. In particular, apoptosis in PA embryos was twice that of IVF embryos on Day 6 (15% vs. 6.7%) and Day 8 (29% vs. 13%). The mean cell number in PA blastocysts was significantly lower than that of IVF blastocysts, whereas the percentage of apoptosis in PA blastocysts was significantly higher than that of IVF blastocysts. There was a high percentage of haploid (62.5%) PA blastocysts. The ploidy may contribute to a high level of apoptosis. These results may help to explain the mechanism of parthenogenetic developmental failure and may lead to methods that will improve parthenogenetic development.
卵母细胞孤雌生殖（PA）对于许多与卵母细胞或胚胎相关的技术至关重要，如胞浆内单精子注射和核移植克隆。本研究通过使用末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记（TUNEL）试验，研究了PA猪胚胎中细胞凋亡的起始和频率，以及符合凋亡细胞死亡一般标准的形态学变化。与体外受精（IVF）相比，PA胚胎在体外培养期间细胞凋亡程度更高，卵裂率更低（45%对71%），发育至囊胚阶段的比率更低（16%对29%）。PA胚胎中最早的阳性TUNEL信号在第6天被检测到，比IVF胚胎晚1天。PA胚胎中的细胞凋亡从第6天的15%增加到第8天的29%。除第5天外，PA胚胎的平均凋亡水平在统计学上高于IVF胚胎。特别是，PA胚胎在第6天（15%对6.7%）和第8天（29%对13%）的细胞凋亡是IVF胚胎的两倍。PA囊胚中的平均细胞数显著低于IVF囊胚，而PA囊胚中的凋亡百分比显著高于IVF囊胚。PA囊胚中有很高比例（62.5%）的单倍体。倍性可能导致高水平的细胞凋亡。这些结果可能有助于解释孤雌生殖发育失败的机制，并可能带来改善孤雌生殖发育的方法。
