Identification Of The Developmental Competence Of Porcine Oocytes In Vitro After The Sorting By Bcb Staning

In vitro the pruduction of porcine embryos,ovaries are maily from the slaughter plant. The selected oocytes come from different growth stages of the follicle, as a result, oocytes have different growth status and the quality of oocytes have diffenrences. In this study, the systematic identification and study of the developmental competence of porcine oocytes in vitro, further validated the method of the screening high quality of oocytes, in order to ensure the efficiency of nuclear transfer to provide the high quality of oocytes.In this study, the GV stage of porcine oocytes were selected with13μmol/L BCB staining. The cell diameter, the rates of porcine oocytes in vitro maturation, cortical granules migration extent, GSH level of mature oocytes, FDA vitality, parthenogenetic developmental potentialand reconstructed embryos developmental potential of oocytes derived from BCB stainning group(BCB+), BCB non-stainning group(BCB-) and control group were abserved respectively, in order to provide quality oocytes for somatic cell nuclear transfer. On this basis, the relation of the timing of the first zygotic cleavage and the developmentalpotential of parthenogenetic embryos was preliminary studied. After BCB staining,mature oocytes do with parthenogenetic activation, cleavage embryos were selected at24h after parthenogenetic activation, and these embryos were transferred into new culture drops to continue fostering, the remainder embryos without cleavage were selected at48h after activation, repeat the above steps,0-48h of the time the embryos as a no time period group, after144h of embryo culture, comparing the embryonic developmental ability of different timing of the first zygotic cleavage, in order to predict the early embryonic develpmental potentiality and provide high quality embryos for embryo transfer of porcine cloning.The results of the study show that:1) The diameter measurement and in vitro maturation condition of porcine oocytes after BCB staining:the BCB+group oocytes diameter was greater than the BCB-group and control group (120.47μm,104.94μm and114.81μm). The rate of BCB+group oocytes maturation was79.61%, the rate of BCB-group of oocytes maturation was53.51%, the control group oocytes was63.64%, each group was significant differences(P<0.05). The staining group was66.59%, there is no significant difference with the control group (P>0.05). 2) The observation of cortical granule migration, GSH levels and FDA vitality after BCB staining:the proportion of cortical granules migrate completely by BCB+group oocytes was79.79%, the BCB-group was27.06%and control group was48.87%, every group was significant differences(P<0.05). The GSH level of BCB+oocytes was significantly higher (P<0.05) than BCB-group and the control group (10.41pmol/oocyte,5.84pmol/oocyte and6.77pmol/oocyte). The cell vitality was91.43%in BCB+oocytes, the BCB-oocytes was54.32%and the control group was72.11%, each group was significant differences(P<0.05). The cytoplasmic maturation of BCB+oocytes was complete, which was helpful with the future development of oocytes.3) The situation of parthenogenetic embryo development and nuclear transfer embryonic development of porcine ppcytes after BCB staining:The rate of parthenogenetic blastocyst in BCB+group was34.28%and the rate of nuclear transfer blastocyst in BCB+group was23.74%which were significantly higher(P<0.05) than BCB-group (12.25%,6.28%) and control group (26.52%,17.05%), and BCB+group blastocyst cell number was more than others.4) The relation of the timing of the first zygotic cleavage and the potential of parthenogenetic embryos:The rate of parthenogenetic blastocyst in BCB+group during0-24h cleavage was44.59%,25-48h was22.86%and0-48h was35.01%, there is significantly different with each group(P<0.05). The rate of blastocyst of BCB-group during0-24h cleavage was22.58%which was higher than25-48h(8.59%) and0-48h(12.47%). Control group appeared that blastocyst rate during0-24h cleavage was35.54%which was higher than others(25-48h was15.88%and0-48h was21.38%). BCB+oocytes have a high blastocyst numbers during0-24h cleavage after parthenogenetic activation.