The Effect Of Heat Shock On Development Of Cloned Embryo

The materials of bovine oocytes are collected from the local slaughterhouse in Xi'an.Thoungh differ temperatures of hear stress on oocyte which unmatured(Control Group,38.5℃;Group 2,39.5℃;Group 3,40.5℃; Group 4,41.5℃;Group 5 42.5℃),Comparing the cleavage rate and blastocyst rate of reconstruct embryo,comparing the total number of blastocyst cell which came from different donor cells,study on the effect of cloned embryonic development caused by short time(30min)heat stress。Do researches on the stages of one cell embryo and morula embryo came from oocytes which have not under the heat shock:(1)Use different temperatures as standard(Grouping as before)heat stress in 30 min,compute the blastocyst rate;(2)Use the temperature which is 2℃higher then control group heat shock in 30min, 1 h, 2h, compute the blastocyst rate。Study on the damage influce on embryo caused by different intensity of heat stress. In conclusion:1 30 min Heat shock on oocyte in 41.5℃,improved the cleavage rate and blastocyst rate of cloned embryo significantly comparing the control group (P<0.05). In the group 5,30 min Heat shock in 42.5℃,Although the cleavage rate was improved,the blastocyst rate was reduced significantly(P<0.05)。2 Research on three different donor cells.Comparing the control group, there are not any significantly differ in No. of blastocyst cells between the cloned embryo formed by heat shock oocyte or not(P<0.05). These results show: the short time heat shock doesn't influence the quality of early embryo. This conclusion should be applicable to an arbitrary donor cell.3 Thought heat stress on the one cell stage cloned embory for 30min,we discovered that there are not deleterious effect significantly of cleavage rate between heat stress and control group during the improving temperature(P>0.05),but the blastocyst rate was gradually reduce.There are significant deleterious effect from the group 4 compared to control group(P<0.05). 4 With heat shock on morula stage cloned embryo in 30 min,the blastocyst rate was reduced when the heat stress temperature improved.There was significant deleterious effect between group 5 and control group(P<0.05).5 With heat stress on one cell stage cloned embryo in 40.5℃,the blastocyst rate was reduced .When the duration time over 1 hour,the influence will be significant(P<0.05).6 With heat stress on morula stage cloned embryo in 40.5℃,the blastocyst rate of cloned embryo was reduced when the heat stress time got longer,but the capability of resist stress was improved compared to one cell stage embryo.When the time passed 2 hours, there was significant influence(P<0.05).