5189
Esraa Aly Sayed Ismail
Genes Regulate Oocyte Competence and Embryo Development in the Buffalo
Buffalo, Oocyte competence, In vitro maturation, IGF, BOEC, Gene expression
This work was carried out for two successive years (2014 and 2015) in order to investigate gene expression of in vitro matured oocytes and blastocysts in buffaloes as well as to study factors affecting the buffalo oocyte and embryo developmental competence. Selected (excellent and good quality) oocytes were cultured in TCM-199 medium at 38.5 ºC, 5% CO2 for 24 hrs. Supplementation of maturation medium TCM with IGF-1 increased significantly (P<0.05) the oocyte maturation, cleavage and transferable embryos rates (morula and blastocyst). ZFP64, BMP15 and ATP5A1, gene expression was increased (p<0.05) in buffalo oocytes matured in TCM-199+IGF. Co-culture of fertilized oocytes using BOEC during in vitro culture of fertilized oocytes increased (P<0.05) the cleavage rate, transferable embryos rate (morula and blastocyst) and upgraded (CX43, CDX2, Oct4, INF-tu) gene expression in blastocysts of buffaloes. BCL2 (Anti-apoptosis gene) was higher (P<0.05) in blastocysts cultured on the SOF group than that observed in SOF with BOEC group. Higher (P<0.05) oocyte yield rate of excellent and good quality was observed during winter versus summer season. Acute heat shock for one hour during in vitro maturation, significantly (P<0.05) decreased the maturation rate and the cleavage rate in buffaloes. IGF-1 supplement in maturation media of acute heat shocked oocyte led to a significant increase (P<0.05) in the maturation rate, the cleavage rate and transferable embryos than matured without IGF. Co-culture (BOEC) in culture medium of acute heat shocked oocyte significantly increased the cleavage rate and blastocyst rate than cultured in SOF. In conclusion, supplementation of maturation media with IGF-1 improved developmental competence of buffalo oocytes and embryos due to its effect on gene expression. Co-culture (BOEC) during in vitro early embryo development significantly increased the transferable embryo rate (blastocyst) in buffaloes due to subsequent upgrade genes regulating early embryonic development (CX43, Oct4, CDX2, INF-tu and BCL2). Acute heat shock significantly decreased oocyte and embryo developmental competence in buffaloes. Both of IGF-1 in maturation medium and co-culture (BOEC) secure the acute heat shock effect on oocyte and embryo developmental competence in buffaloes.
2016
M.Sc
Cairo
Veterinary Medicine