Table 1. In vivo development of mouse ICSI embryos using sperms with their tails artificially removed.
| Animal | Treatment of sperm | Pre-activation of oocyte | No. of oocytes injected | No. of oocytes survived (%) * | No. of embryos developed to |
No. of embryos transferred | No. of offspring (%) *** | |
|---|---|---|---|---|---|---|---|---|
| pn (%) ** | 2-cell (%) ** | |||||||
| Mouse | Piezo-cut | – | 116 | 93 (80) | 91 (98) | 91 (98) | 91 | 49 (54) a |
| Naturally tail less | – | 55 | 53 (96) | 52 (98) | 50 (94) | 50 | 8 (16) b | |
| –30°CFT | – | 119 | 110 (92) a | 98 (89) | 88 (80) | 88 | 9 (10) b | |
| –30°CFT | + | 60 | 60 (100) b | 60 (100) | 57 (95) | 57 | 12 (22) b | |
| LNFT | – | 126 | 105 (83) | 103 (98) | 100 (95) | 100 | 37 (37) b | |
| LNFT | + | 60 | 55 (92) | 55 (100) | 51 (93) | 51 | 10 (20) b | |
| Glass-beads | – | 60 | 52 (87) | 18 (35) | N.D. | N.D. | N.D. | |
| Glass-beads | + | 119 | 111 (93) | 111 (100) | 105 (95) | 105 | 19 (18) b | |
| Trypsin | – | 60 | 41 (68) a | 11 (27) | N.D. | N.D. | N.D. | |
| Trypsin | + | 109 | 96 (88) b | 93 (97) | 93 (97) | 93 | 48 (52) a | |
| TS | – | 60 | 44 (73) a | 11 (25) | N.D. | N.D. | N.D. | |
| TS | + | 109 | 94 (86) b | 93 (99) | 89 (95) | 89 | 23 (26) b | |
* Percentages relative to the number of oocytes injected. ** Percentages relative to the number of oocytes survived. *** Percentages relative to the number of embryos transferred. Each experiment was repeated three times. N.D.: not determined. pn: pronucleus. – indicates not artificially activated oocyte. + indicates artificially activated oocyte. Statistical analysis of oocyte viability was performed between – and + oocytes before activation for each treatment, and that of the number of offspring was performed between piezo-cut control and each treatment. Significant χ2 comparisons a vs. b, P < 0.05.