Table 1. Mouse Pronuclei Initiate DNA Synthesis Synchronously.
Mouse one cell embryos were generated by ICSI or IVF, and incubated with BrdU at various times after fertilization. The numbers of oocytes with 0, 1 or 2 pronuclei (PN) that incorporated BrdU are shown.
| Exp. | Hr after Fertilization1 |
No. (%) Oocytes with BrdU Positive Pronuclei (PN) |
||
|---|---|---|---|---|
| 0 PN | 1 PN | 2 PN | ||
| ICSI | 5 | 17 (94) | 0 | 1 (6) |
| 6 | 9 (32) | 0 | 19 (68) | |
| 7 | 4 (19) | 0 | 17 (82) | |
| 8 | 0 | 0 | 34 (100) | |
| IVF | 5 | 29 (83) | 1 (3) | 5 (14) |
| 6 | 5 (19) | 0 | 21 (81) | |
| 7 | 1 (6) | 0 | 17 (94) | |
| 8 | 1 (6) | 0 | 15 (94) | |
1
Fertilization = approximate moment of sperm-oocyte fusion; in IVF this was 30 min after initiation of gamete co-incubation and in ICSI it was the end of ≤ 10 min long injection of one group of oocytes.