|Budget Amount *help
¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1994 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1993 : ¥800,000 (Direct Cost : ¥800,000)
We studied the probability of the successful fertilization using an electrofusion methods, and obtained the following results.
1.In the experiments that three to ten mouse sperms were injected into the perivitelline space of each mouse oocytes, the best results of sperms attachment, fertilization were obtained after application of dc of 3.5KV/cm, 10musec followed by ac pulses (2MHz, 100V/cm, 20sec each). After pulse application, 25.5% of the oocytes were fertilized. However, 90% of the oocytes showed the polyspermic fertilization and 15.5% of the oocytes were degenerated.
2.Oocyte activation prior to application of fusion pulse is known to facilitate oocyte-sperm fusion. When the oocytes were electroactivated by exposures to ac pulse (2MHz, 50V/cm, 10sec) and followed by dc (1.5KV/cm, 50musec), about 70% of the oocytes were activated. Twenty percents of the oocytes stimulated with electoactivation developed to the pronucleus stage after the application of the electrofusion. However, all these oocytes were arrested at the PN stage.
3.When a single mouse sperm was injected into the perivitelline space and applied an electrofusion technique, 12.5% of these oocytes were fertilized and developed to the PN stage.
4.In the trial using human sperms and hamster oocytes, 3.0% of the hamster oocytes were ferilized under the same conditions of electrofusion. However, all oocytes were arrested at the PN stage and 15.0% of the oocytes were degenerated.
Although the success rate is very low and more study about the best conditions for electrofusion is needed, our preliminary results may offer important prospects of the treatment of the patients with sperm dysfunction.