Activation treatment of recipient oocytes affects the subsequent development and ploidy of bovine parthenogenetic and somatic cell nuclear transfer (SCNT) embryos.

We evaluated the potential effect of anisomycin, an antibiotic produced by Streptomyces griseolus, on the parthenogenetic activation of bovine oocytes and reconstructed somatic-cell nuclear transfer (SCNT) embryos. A higher cleavage and blastocyst rate were achieved with anisomycin (70.3% and 27.8%) and 6-dimethylaminopurine (DMAP) (73.3% and 30.2%), relative to oocytes parthenogenetically activated with cycloheximide (CHX) (54.1% and 20.2%). In reconstructed SCNT embryos, a greater proportion of embryos reached the blastocyst stage after anisomycin (32.2%) compared to DMAP (22.3%) and CHX (23.5%) treatment. Furthermore, the quality of embryos-assessed by the total number of cells and the inner cell mass-to-total-cell ratio-was higher with anisomycin (166.2 ± 6.9 and 26.9 ± 1.9) compared to DMAP (135.0 ± 8.7 and 39.4 ± 3.5) and CHX (149.1 ± 8.4 and 36.3 ± 2.5), while a lower percentage of chromosomal abnormalities was observed with anisomycin compared to DMAP and CHX treatments, both in parthenotes (though not significant) and in SCNT embryos (P < 0.05). Therefore, anisomycin can enhance the in vitro developmental potential in parthenotes and reconstructed SCNT embryos, specifically improving the quality of SCNT embryos and decreasing the abnormal ploidy of parthenotes and SCNT embryos compared to the traditional protocols of chemical activation with DMAP and CHX. These results may have important implications for the success of reproductive technologies, including SCNT and intracytoplasmic sperm injection, in different mammalian species.