The Study Of Effect Factors On The In Vitro Development Of In Vitro Fertilization Zygotes In Bovine

The aim of this study is to make a further study of in vitro maturation, in vitro fertilization and zygotes in vitro development in bovine, and the points are the studies of serum added concentration and bovine Sertoli cells effects on in vitro development of in vitro fertilized bovine zygotes, in order to improve the cleavage rate and blastocyts rate.1. 10%NBS, 8 g/LBSA and 1 g/LPVA were added in SOF medium respectively to culture bovine IVF zygotes. The results showed that, the cleavage ratea and the blastocyte rates all decended obviously when the zygotes were cultured by the medium supplemented with PVA or BSA to replace NBS. When the zygotes were cultured by SOF medium with 5%NBS for the first 48h, then cultured by SOF medium with 10%NBS, the developing results of the zygotes didn't improved obviously, and can reduce the serum consuming. Collect the 7th day oestrus cow serum (OCS) to compare with the NBS, the cleavage rate and blastocyst rate of the two groups didn't different significantly, the results indicated that, OCS and replace NBS to effect to bovine early embryos.2. Effect of bovine fetal SCs feeder layer on the development of bovine zygotes in vitro was studied. Collect 5-7 months bovine fetal testiculus from slaughter, made bovine fetal sertoli cells (SCs) monolayer by primary culture and sub-culture, then co-cultured with bovine IVF zygotes and compared the developing results of zygotes; sub-cultured SCs was inoculated in 2.0×104/mL and 4.0×104 /mL, to carry out co-culture with bovine in vitro fertilized (IVF) zygotes, and set up control group The results showed that: when IVF zygotes co-cultured with sub-cultured bovine fetal SCs (sub-culture group), the cleavage rate of zygotes (79.3%) was higher than those co-cultured with primary cultured SCs (primary group) (69.2%), but there was no significant different (P>0.05); the blastocyst development rate (41.3%) was significant higher than primary passage group (16.7%) (P<0.01). Cleavage rate of zygotes co-cultured with SCs which inoculated in 2.0×104 /mL was not sifnificant different with that of in 4.0×104 /mL, but as the lasting of the cultivation, the embryo development rate descended obviously as the concentration of the feeder layer increased,. Conclusions: the fetal bovine SCs feeder layer made by sub-culturing cells can efficiently promote the in vitro development of bovine IVF zygotes, and increasing the blastula quality; too high concentration of sub-culturing SCs feeder layer will effect the development of co-cultured bovine IVF zygotes obviously.