Kim N H, Shin J S, Kim C, Jun S H, Lee H T, Chung K S
Animal Resources Research Center, Kon-Kuk University, Mojin-dong, Seoul, Korea.
Theriogenology. 1999 Jun;51(8):1441-9. doi: 10.1016/s0093-691x(99)00088-6.
The objective of this study was to determine fertilization rates and developmental ability of porcine oocytes following injection of round spermatid and round spermatid nucleus with artificial activation either 2 h before or immediately after injection. Electrical stimulation at 2 h before spermatid injection significantly increased the incidence of normal fertilization compared with that following injection without stimulation or with stimulation immediately after injection. Incidences of formation of 2 pronuclei and of apposition were not different in oocytes following intracytoplasmic spermatid and spermatid nucleus injection. Chromosome analysis revealed that most oocytes were diploid either following round spermatid or round spermatid nucleus injection. There was no diploid set of chromatin in oocytes at 20 h following sham injection. At 6 d following injection blastocoele formation was seen in the oocytes following round spermatid (25%) and round spermatid nucleus injection (27%). However, none of the oocytes developed to the blastocyst stage 6 d following sham injection. The average cell numbers of blastocysts 8 d after injection of spermatid and spermatid nucleus were 99 and 87, respectively. These results suggest that electrical stimulation before injection enhances the incidence of fertilization following round spermatid injection in the pig. Our study also indicates that either the round spermatid or it's nucleus can be used to produce viable embryos by injection into unfertilized porcine oocytes.
本研究的目的是确定在注射圆形精子细胞和圆形精子细胞核后，于注射前2小时或注射后立即进行人工激活的情况下，猪卵母细胞的受精率和发育能力。与未刺激注射或注射后立即刺激相比，在精子细胞注射前2小时进行电刺激显著提高了正常受精的发生率。胞质内注射精子细胞和精子细胞核后，卵母细胞中双原核形成和并列的发生率没有差异。染色体分析显示，注射圆形精子细胞或圆形精子细胞核后，大多数卵母细胞为二倍体。假注射后20小时，卵母细胞中没有二倍体染色质组。注射后6天，在注射圆形精子细胞（25%）和圆形精子细胞核的卵母细胞中可见囊胚腔形成。然而，假注射后6天，没有卵母细胞发育到囊胚阶段。注射精子细胞和精子细胞核后8天，囊胚的平均细胞数分别为99和87。这些结果表明，注射前的电刺激可提高猪圆形精子细胞注射后的受精率。我们的研究还表明，圆形精子细胞或其细胞核均可通过注射到未受精的猪卵母细胞中产生有活力的胚胎。
