EFFECT OF BOVINE SERUM ADDED TO MATURATION MEDIUM ON IN VITRO-MATURATION AND SOME GENES EXPRESSIONS OF BUFFALO OOCYTES

The effect of supplementing TCM-199 culture medium with bovine sera on buffalo’s oocytes maturation in vitro and expression of  some related genes were studied. A total 1149 immature buffalo oocytes were randomly divided into three groups, G1( n=315) were cultured in medium with no serum supplement(control), G2( n=531) were cultured in medium supplemented with 10% Fetal calf serum (FCS) and G3(n= 303) were cultured in medium supplemented with 10% Estrous cow serum (ECS). After maturation, oocytes in each group were classified according to its shape and expansion into 2 subgroups, good (GO) and fair (FO) expanded oocytes. Expression of GAPDH, CX43, IGF II and β- Actin genes were studied in each subgroup. Results revealed that G3 and G2 showed high maturation rate (P<0.01 & 0.05 respectively)  compared to G1(control) and ECS was superior  (P<0.05) than FCS. The qualitative expression of genes under study showed no difference among the studied groups, except CX43 gene expression  was missed in FO in G1 concluding that addition of bovine sera especially estrus cow serum enhance in vitro maturation of the buffalo oocytes and CX4 gene expression and further studies is needed to enhance the expression  of CX43 gene which might help in increasing maturation rate.