Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Animal Production

This study was performed to investigate the effects of physiologically relevant heat shock during oocyte maturation on the developmental competence of Egyptian buffalo oocytes and the expression of heat stress genes. This study was designed into three experiments. The first and second experiments were run on three groups, (n=250 oocyte/group), buffalo cumulus oocyte complexes (COCs) were cultured at 38.5{u00B0} C (T0, control) or were exposed to 39.5{u00B0} C (T1) or 40.5{u00B0} C (T2) for the first 6 h of the in vitro maturation (IVM). After this period, all groups were incubated at 38.5{u00B0}C up to the blastocyst stage (7 day). In the 1st experiment, the groups were exposed to the assigned temperatures to study the effect of partial exposure of buffalo oocytes to heat stress (T1 and T2) on their maturation rate. The 2nd experiment has studied the ability of in vitro fertilized buffalo oocytes to develop until the blastocyst stage after being exposed to partial heat stress (T1 and T2). The 3rd experiment was conducted to draw the profile of mRNA expression of selected target genes (HSF-1, HSF-2, HSP-70, HSP-90, BAX, P53, SOD1, COX1, MAPK14) in denuded oocytes and their isolated cumulus cells resulted from control COCs as well as from COCs exposed to 39.5{u00B0} C (T1)

Issued also as CD