Quality of in vitro ovine embryo production: lambing rate, body weight and gene expression

The objective of this study was to examine the effect of different culture media on in vitro embryo production in terms of pregnancy rate, lambing rate, lamb body weight and to compare gene expression in in vivo vs in vitro embryos. Blastocysts were in vitro produced in different culture media with BSA at different doses or serum and divided in: A(BSA4), B(BSA8), C(BSA8–HA), D(BSA8-CH) and E (FBS10) groups. On day 6-7 blastocysts (A, B, C, D groups) were transferred into recipient ewes either fresh or after vitrification. For gene expression in vitro produced and in vivo derived (F group) fresh embryos were analyzed by quantitative Real Time PCR. Gene expression for imprinting (IGF2R, GRB10, UBE2A), embryo development (LAMA1, IL-6, FGF4), apoptosis (BAX) and methylation (DNMT3A) was analyzed.Pregnancy and lambing rate were similar only for fresh groups, while among vitrified groups A vs D showed significant difference (P <0.05). The birth weight was higher for B and C within groups both fresh and vitrified. However, IGF2R and UBE2A were significantly upregulated (P<0.05) in in vitro groups compared with in vivo group.Furthermore, UBE2A was significantly upregulated (P<0.05) in C compared with to other in vitro groups. LAMA1 was significantly upregulated (P<0.05) in group A compared to all groups.Our data confirm that use of different culture media affects the blastocysts quality in terms of cryotolerance, body weight and gene expression.