| dc.description.abstract | The aim of this study is to optimize the condition for enucleation of matured bovine oocytes and somatic cell nuclear transfer (SCNT) in bovine.
In vitro matured bovine oocytes at the metaphase II stage were enucleated under micro-manipulator system and PIEZO system by using 8μm diameter micro-pipette. Two methods of enucleation were performed. The enucleated oocytes were confirmed by staining with Hoechst 33342. Percentage of oocytes before and after enucleation were calculated to investigate the succeed rate after removal of the metaphase II chromosomes between two methods.
For examine of somatic chromosomes reorganization after SCNT, nuclei of bovine cumulus cells were transferred into in vitro matured intact bovine oocytes, and chromosome remodeling were examined by aceto-orcein staining after SCNT at 0.5h, 1h, 2h and 3h. Our data showed that during 3h after nuclear transfer, the oocytes chromosomes still maintained at metaphase II. Moreover, in the first 2 h after SCNT, a series of morphology changing were observed in the cumulus nuclei: nuclear envelope disassembly at 0.5h to 1h after SCNT; then chromosome condensation to form a metaphase-like structure at 2h to 3h after SCNT. The metaphase-like structure of cumulus cell nucleus was observed approximately 71.42% at 3h after injection. This results shown that, the stages of cumulus cell nucleus were controlled by the cytoplasm of matured oocytes.
In conclusion, the success of enucleation and somatic cell nuclear transfer demonstrates that it is possible to create bovine clone embryo with expected characteristic in Viet Nam under optimum condition in the future.
Key words: somatic cell nuclear transfer (SCNT), enucleation, enucleated oocytes, in vitro mature oocytes, chromosome remodeling. | en_US |
