Effects of Electrical Pulse and 6-DMAP on Cleavage of Golden Hamster Oocytes—Morphological and Phisiological Observations

The golden hamster is a well-established model system for studies of morphology, reproductive physiology, oncology, genetics and virology. The aim of this study was to establish experimental protocols necessary for cloning the golden hamster; we examined and optimized conditions for parthenogenesis and cleavage of its oocytes. We tested oocytes of different ages, including 15 h after Human chorionic gonadotropin (hCG), with two treatments: (1) an electrical pulse ranging from 10 to 600 V/mm and (2) incubation for 2 to 6 h in 2 mM 6-dimethylaminopurine (6-DMAP). These two conditions were tested both separately and in combination. We found that (i) in oocytes of different ages, cleavage exhibits a strength-dependent increase; (ii) 6-DMAP stimulates oocyte cleavage, but the cleavage rates are significantly low; and (iii) a combined treatment is more effective than a treatment with 6-DMAP alone, and is comparable to those achieved with high pulse stimuli. These results elucidate certain parameters important for the cloning of the golden hamster species.