Artificial Activation of Oocytes from Sinclair Miniature Pigs

Abstract

Prather, R.S., Gibson, J. and Parry, T.W. 1996. Artificial activation of oocytes from Sinclair miniature pigs. J. Appl. Anim. Res., 10: 125–134.

The experiments reported in this paper are designed to evaluate in Sinclair miniature pig oocytes a number of stimuli that are known to result in activation of domestic pig and mouse oocytes. The rationale for such experiments is two fold: 1) to provide an initial characterization of mechanisms that may be responsible for activation at fertilization in miniature pigs oocytes and 2) to initially characterize methods that may be useful for activating oocytes for nuclear transplantation and cloning. In Experiment 1 all staurosporine treated oocytes activated; whereas, neither treatment with phorbol 12-myristate 13-acetate, nor control media resulted in any activation. In Experiment 2, A23187 resulted in 609c of the oocytes activating while none of the controls activated. Experiment 3 evaluated multiple electrical pulses on oocyte activation, but resulted in no significant difference after six days in culture. Experiment 4 evaluated the effect of including cycloheximide in the culture medium for the first 20 hours of the 6 day culture on the development of electrically activated in vivo matured Sinclair miniature pig oocytes. Inclusion of cycloheximide during the first 20 hours of culture increased (P=0.008) the number of nuclei present after a 6 day culture. Some compact morulae and a blastocyst were obtained after these treatments. It is concluded that in vivo derived oocytes fionz Sinclair miniature pigs respond to activation stimuli in a manner similar to in vitro matured oocytes from domestic pigs, but they are more developmentally competent.

Key words:

• Miniature pig
• fertilization
• nuclear transfer
• cloning