S. Hwang et al., Effects of electric stimulation on bovine oocyte activation and embryo development in intracytoplasmic sperm injection procedure, J AS REPROD, 17(6), 2000, pp. 310-314
Purpose: This study was carried out to investigate the efficacy of electric
stimulation before and/or after intracytoplasmic sperm injection (ICSI) on
bovine oocyte activation and embryo development.
Methods: The oocytes were treated with electric shock before (B), before an
d after (B&A), and after (A) sperm injection. In each group, sham ICSI (ICS
I-s) was performed to exclude the effect of parthenogenesis (B ICSI-s, B&A
ICSI-s, and A ICSI-s). An electric pulse was applied with a single direct c
urrent (DC) pulse (0.8 kV/cm, 70 mu sec).
Results: One pronucleus (PN) formation in the B&A ICSI-s group was slightly
higher than that found in B and B&A ICSI group; however, the difference wa
s not significant. Two PN formation in B&A ICSI group was higher than that
found in sham ICSI groups (P < 0.05). There was no differences among treatm
ent groups in the cleavage rate; however, morulae and blastocyst formation
in the B&A embryos was significantly higher than that of other groups (P <
0.05) and got pregnant.
Conclusions: Electric stimulation before and after injection was an effecti
ve method in inducing bovine oocyte activation and in sustaining embryo dev
elopment to the morulae and blastocyst stage.