earticle

영어

The main purpose of this study is to estimate the effect of adding Tea-N-Tris to the freezing buffer for miniaturepig sperm. In particular, we attempted to identify the association between the MMPs expression and the survival and viability of sperms. Prior to freezing, sperms in LEY without Tea-N-Tris showed 40.3±2.8% viability and 60.3±1.3% acrosome intact rate at 4℃. After freezing, sperms stored in LEY (lactose+Egg yolk) with Tea-N-Tris (=TLE) showed the highest viability (57.4±1.8%) and acrosome intact rate (65.6±4.6%). In accordance with this, DNA fragmentation was the highest among sperms frozen in LEY while the lowest fragmentation was observed among sperms frozen in TLE. When these sperms were used for in vitro fertilization (IVF), the LEY group showed lower rate of blastocyst development, although the difference was not statistically significant. Meanwhile the rate of blastocyst development appeared similar when sperms from TLE and TFGE (Tea-N-Tris+Fructose+ Glucose+Egg yolk) group were used for IVF. We observed MMPs expression in all sperm groups, with pro-MMP showing lower expression than active MMPs. The expression of MMP-9 and MMP-2 was the highest in sperms frozen in LEY, Meanwhile, sperms from the TFGE and TLE group showed lower level of MMP-9 and MMP-2 expression in the order of TLE being the lowest. Together, these results indicate that adding Tea-N-Tris to the sperm freezing buffer would not only suppress MMPs expression but also minimize DNA fragmentation, providing a mean to improve the success rate in the in vitro manipulation of miniaturepig sperms. * This work was supported by BioGreen 21 Program (No. PJ008029). Rural Development Administation, Republic of Korea.