135 effect of XXXX supplementation during culture on in vitro embryo development in buffalo (bubalus bubalis).

@entity1 @entity274 @entity26 @entity43452 @entity515 @entity3787 @entity273 @entity920 @entity2145 @entity68
It is known that in vitro @entity1 embryo development is negatively affected by the increased oxidative stress occurring under culture conditions. The oxidative damage of cell components via reactive @entity26 species interferes with proper cell function. Buffalo embryos are particularly sensitive to oxidative stress because of their high lipid content (Boni et al. 1992 Acta Med. Vet. 38, 153-161). @entity43452 (LE) is a powerful scavenger of @entity3787 radicals ( @entity2145 ) and an inhibitor of @entity68 or @entity920 ion-dependent generation of @entity2145 from @entity273 ( @entity274 ). The aim of this study was to evaluate whether enriching the in vitro-culture medium with LE improves in vitro embryo production efficiency in buffalo. Abattoir-derived buffalo oocytes (n=854, over 6 replicates) were in vitro matured and fertilized according to standard procedures (Gasparrini et al. 2006 Theriogenology 65, 275-287). Twenty hours after IVF presumptive zygotes were cultured in SOFaa supplemented by 8mgmL(-1) BSA in a controlled gas atmosphere consisting of 5% @entity515 , 7% O2, 88% N2, in humidified air, at 38.5  C with 0 (control; n=214), 0.05mM LE (n=217), 0.1mM LE (n=204), and 1mM LE (n=219). Cleavage rate was assessed at the time of change of culture (Day 5) and the cleaved elements were cultured for a further 2 days. The embryos obtained by the end of culture, i.e. on Day 7 post-IVF, were scored for quality, based on morphological criteria, and for developmental stage, as previously described (Robertson, Nelson 2010 Manual of the International Embryo Transfer Society 86-105). The percentages of total transferable embryos and Grade 1 and 2 blastocysts in relation to cleaved oocytes were recorded. Because the chronology of development is known to be one of the most reliable parameters for assessing quality, the percentage of fast-developing embryos, i.e. hatched and expanded blastocysts, was also recorded. Data were analysed by Chi-squared test. Cleavage rate was not affected by the treatment (71.4, 66.8, 68.7, and 63.0%, respectively, with 0, 0.05, 0.1, and 1mM LE). The total embryo output increased in groups supplemented with 0.05 and 0.1mM LE (31.3, 42.2, 43.8, and 21.7%, respectively, with 0, 0.05, 0.1, and 1mM LE; P<0.05). However, the enrichment of in vitro culture with 0.1mM LE also increased the percentage of Grade 1 and 2 blastocysts compared with the control and to 1mM LE (21.6, 30.9, 33.9, and 21.7%, respectively, with 0, 0.05, 0.1, and 1mM LE; P<0.05). Likewise, 0.1mM LE gave higher percentages of fast developing embryos than the control and 1mM LE groups. In conclusion, these results demonstrated a beneficial effect of LE during culture on buffalo in vitro embryo development. The dose response trial indicated that the optimal concentration is 0.1mM that also influenced the chronology of development and hence embryo viability.
