A combination of calcium ionophore and puromycin effectively produces human parthenogenones with one haploid pronucleus
Parthenogenetic activation with various combinations of the calcium ionophore A23187 and protein synthesis or phosphorylation inhibitors was investigated as a means of producing human parthenogenones with one haploid pronucleus. Unfertilised human aged oocytes exposed to 5 μM A23187 for 5 min were treated with 10 μg/ml puromycin (puromycin group, 46 oocytes) or 2 mM 6-dimethylaminopurine (DMAP group, 42 oocytes) for 5 h. Oocytes treated only with A23187 served as a control (control group, 40 oocytes). After washing the oocytes, they were incubated for up to 37 h. Evidence of activation (pronuclear formation) and cleavage was observed 18 h and 42 h after A23187 treatment, respectively. Activation rates in the puromycin and DMAP groups were significantly higher than in the control group (91% (42/46) and 77% (34/44) vs 20% (8/40), p < 0.05, respectively). In the puromycin group, 81% (34/42) of the activated oocytes showed one pronucleus with the second polar body (2ndPB), whereas none (0/34) of the activated oocytes in the DMAP group extruded the 2ndPB. The cleavage rate in the puromycin group was significantly lower than in the DMAP group (38% vs 68%, p < 0.05). The activated oocytes which had one pronucleus with the 2ndPB in the puromycin group showed a haploid set of chromosomes (10/13). In conclusion, the combination of A23187 and puromycin is effective for producing human parthenogenones with one haploid pronucleus.(Received June 14 2000)
(Accepted September 5 2000)
Key Words: Calcium ionophore A23187; Haploid pronucleus; Human parthenogenones; Oocyte activation; Puromycin.
c1 All correspondence to: Koji Nakagawa, MD, Department of Obstetrics and Gynaecology, School of Medicine, The University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan. Tel: +81 88 633 7177. Fax: +81 88 361 2630.