a1 Monash Immunology and Stem Cell Laboratories (MISCL), Building 75, Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
a2 Monash Immunology and Stem Cell Laboratories (MISCL), Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
a3 Institute of Bioengineering, Northwest Science and Technology University of Agriculture and Forestry, Yangling, 712100, China.
a4 Department of Biology, Inner Mongolia University, Huhhot, 010021, China.
a5 College of Life Science, South China Normal University, Guangzhou, 510631, China.
Oocyte activation is an essential step in animal cloning to allow subsequent development of the reconstructed embryos. A special activation protocol is required for different animal species. The present study investigated low temperature, electrical pulses, ethanol, ionomycin and strontium for goat oocyte activation in order to optimize the protocols. We found, as a result, effective activation and parthenogenetic development of goat oocytes that had been derived from ionomycin, strontium and electrical pulse groups. Within each group 79.3–81.6%, 2.2–78.8% and 65.5% of the oocytes cleaved and 16.2–24.8%, 0–15.6% and 11.1% of the cleaved embryos developed into blastocysts when the oocytes were activated by ionomycin combined with 6-dimethylaminopurine, strontium plus cytochalasin B and electrical pulses combined with cytochalasin B, respectively. However, low temperature and ethanol were both unable to activate goat oocytes under our experimental conditions. When ionomycin combined with 6-dimethylaminopurine and strontium plus cytochalasin B was applied to activate somatic cell nuclear transfer embryos derived from cultured cumulus, 51.0% and 72.5% of the embryos cleaved, respectively. After transfer of 4-cell embryos into recipients, one (1/19 and 1/7) of the recipients from each group was found to be pregnant as detected by ultrasound, but both of these recipients lost the embryos between 45 and 60 days of pregnancy.
(Received October 19 2008)
(Accepted April 17 2009)
(Online publication June 08 2009)
c1 All correspondence to: J Guo. Monash Immunology and Stem Cell Laboratories (MISCL), Building 75, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. Tel: +61 3 99050746. Fax: +61 3 99050680. e-mail: email@example.com