Study On Intracytoplasmic Sperm Injection In Sheep

This paper studied the influence of sheep intracytoplasmic sperm injection(ICSI)factors in order to optimize the sheep ICSI technique and in vitro maturation system.It can provide further technical support to research mechanism of development and improve the efficiency of sheep ICSI.The results were as follows:(1)The different seasons effect on ovine oocytes cultured in vitro.The results showed that the season had not effect on the number of oocytes.The number of usable oocytes obtained from spring and autumn were significantly higher than those from summer and winter.However,the differences between spring,autumn and winter were not significant for the maturation rates.In conclusion,the best season of sheep oocytes cultured in vitro was fall,and the worst is summer.(2)The different maturation duration(20~22h,22~24 h,24~26 h,26~28h)impact on ICSI.The results showed that the cleavage rates of oocytes gradually increased with the extension of time;But the morula/blastocyst rate is the highest when the oocytes matured for 22~24 h.(3)The hypertonic solution effect on ICSI.It was found that the hypertonic solution can significantly improve the success rate of ICSI.However,it was not significantly different between the cleavage rate(43.9 % vs 36.5%,P> 0.05)and the morula/blastocyst rate(41.4 %vs 38.7%,P> 0.05).(4)The position of the first polar body(6:00 and 12:00)impact on ICSI.It was found that polar body position for ICSI is not significantly different between the oocyte cleavage rate(32.5% vs 34.5%,P> 0.05)and the morula/blastocyst rate(33.6%,33.3 %;P> 0.05).(5)The effect of ultrasonic treating of fresh and frozen semen on ICSI.The results showed that the oocyte cleavage rate(39.1% vs 37.4%)andthe morula/blatocyst rate had no significant difference between fresh and frozen semen..(6)The effect of sperm treatments(NaOH and ultrasonic treatment)on ICSI.The results showed that the oocyte cleavage rate(37.4% vs 46.6%,P<0.05)and the morula/blastocyst rate(52.1% vs 35.1%;P> 0.05)was significantly different.(7)The sperm incubation with plasmid impact on ICSI.The sperm was treated with Na OH as a control,sperm treated by Na OH and then incubation with plasmid reduced ICSI embryo cleavage rate(37.9% vs 46.6%)andthe morula/blatocyst rate(45.3%vs52.1%)had significant difference.(8)The culture system of co-culture of cumulus cells impact on ICSI.The results showed that the culture systemwas not significantly different between cleavage rate(41.7% vs 44.0%,P> 0.05)and the morula/blastocyst rate(41.8% vs 35.7%,P> 0.05).