Improvement Of Bovine SNCT Efficiency With Tetraploid Complementation

Tetraploid embryo complementation cure vascular degeneration through improving the placental volume by interactions of tetraploid and diploid during the period of fetal development so that improving the birth rate. This experiment was produced bovine tetraploid embryos by electric fusion method and to test the total numbers of tetraploid blastocyst cells and chromosome. Polymerization of8-cell tetraploid and8-cell somatic cell clone or inner cell mass was producted2n/4n chimeras. Now this experimental will study on the content and results summarized as follows:1. The best time of the production of tetraploid embryos was explored. In vitro fertilization (IVF)embryos in embryo culture medium for statistical training to2-cell stage, the most time of embryos in phase2-cell number was choosed to tetraploid embryo preparation time. The results showed that the number of2-cell stage embryos in14h was the most numerous, so14h was the optimal time for the production of tetraploid embryos.2. The optimal parameter of the tetraploid embryo fusion was groped. The results show that compared with the other two groups, the group of100v/mm,20μs,one pulses were the highest in survival rate (93.71±5.31%), the fusion development rate (70.37±7.07%) and blastocyst rate (19.44±3.62%) of tetraploid embryo(P<0.05) and no significant differences with the group of90v/mm,20μs, the two pulses in phase2-cell embryo fusion rate(P>0.05). And compared with control group, Ion-6DAMP activation group were no difference in cleavage ratio (43.30±6.27%vs53.98±14.97%) and blastocyst rate (4.92±1.12%vs7.14±3.32%). Without activated,100v/mm,20μs,1pulse was selected as the parameters of the preparation of tetraploid embryos.3. The devleopment ability of the bovine tetraploid embryo and embryo quality were test. By observing bovine tetraploid embryo development, boine tetraploid embryos had the ability of development to the blastocyst and reaching to expansion. Blastocyst rate was significantly lower compared with ordinary IVF (19.44±3.62%vs21.77±5.75%).4. Quality of tetrapliod blastocysts was test by analysing the total number of blastocyst cells and apoptosis. The total cell number of tetraploid blastocyst group (101.6±13.65%)was less than IVF group (13.65±26.09%)(P<0.05), and the cell volume was bigger. Apoptosis index of tetraploid blastocyst cells (35±8.5)was significantly higher than diploid blastocysts (14±4.5)(P<0.01). So tetrapliod blastocyst was poor quality. Analysis of chromosome type showed that produced blastocysts as tetraploid blastocyst (2n=120).5. The selecting rabbit anti-cattle serum complement to dissolve and guinea pigs to preparation in trophoblast cells. The production of chimeic embryos was aggregated8-cells cloned embryos or cloned inner cells mass with8-cell of tetraploid. Results showed that chimeric embryos of cloned embryo8-cell with8-cell of tetraploid can get mosaic blastocysts, blastocyst rate was15.67±5.72%.