The Effect Of The Gene Expression Of Cathepsin In Cumulus Cells On In Vitro Developmental Capacity Of Oocytes From Sheep

This experiment was conducted to study the mRNA expression pattern of cathepsin (CTSB,CTSS) in cumulus cells from audal and Juvenile sheep during in vitro maturation(IVM),to detecte the correlation beween the mRNA expression of CTSB,CTSS in cumulus cells and developmental capacity of oocytes from sheep. CTSB,CTSS mRNA expression of cumulus cells from sheep declined with maturation time .CTSB,CTSS mRNA expression abundance at IVM 24h decreased 2,5 times and 2,6 times than that of IVM 0h respectively in audal and Juvenile sheep; the CTSB,CTSS expression abundance of cumulus cells from juvenile sheep is differ very significantly than from audal sheep(P<0.01).The CTSB,CTSS mRNA expression from Juvenile increased respectively 9 times and 8 times than audal sheep at IVM 0h,The CTSB,CTSS expression from Juvenile increased respectively 7 times and 8 times than audal sheep at IVM 24h.Mature medium containing cathepsin inhibitor E-64 can down-regulate the mRNA expression abundance of cathepsin in cumulus cells from sheep.The mRNA expression of CTSB,CTSS of E-64 group (10μmol/L) were down-regulated than that of the control(P<0.01).The rate of matured oocytes was respectively 82.78%.81.76%,80.54%,83.89% when the oocytes was cultured mature medium containing 0μmol/L(the control),1μmol/L,5μmol/L and 10μmol/L E-64 and there were no significantly differences each other(P>0.05);the rate of cleavaged oocytes was respectively 53.74%,53.89%,56.58%,55.35% and there were no significantly differences each other(P>0.05)but the rate of blastocyst in the groups of 5μmol/Land 10μmol/L(26.82%;30.95%)were more than those of the control and 1μmol/L (15.63%;18.23%) (P<0.05);there were no significantly differences between the control and the group of 10μmol/L E-64(P>0.05),but mature medium containing 10μmol/L E-64 can improve the rate of cleavage(P< 0.05).The progress on the meiosis of oocytes from juvenile sheep is slowly than audal sheep and there are some Juvenile oocytes be GV state all time lead to that it can not resume meiosis;cumulus expantion is no obvious at IVM 8h,but it to show expantion gradually at IVM 16h until full expention at 24h. Adding 10μmol/L E-64 in mature medium was conducive to cumulus expantion.