In vitro development of cloned embryos derived from miniature pig somatic cells after activation by ultrasound stimulation.

The present study was carried out to examine the activation and development of cloned embryos produced by transferring miniature pig somatic cells into enucleated farm pig oocytes after exposing to ultrasound. The rates of the pronucleus-like structure formation and polar body-like structure extrusion in embryos exposed to ultrasound did not differ from those applied electric pulses. Although there was no significant difference in the blastocyst formation rates between different activation methods, the mean number of cells in the blastocysts developed from embryos activated by exposing to ultrasound was significantly (p < 0.05) higher than that obtained by applying electric pulses. The results of the present study showed that ultrasound stimulation can induce the activation and in vitro development of cloned embryos derived from miniature pig somatic cells.