Abstract Text: This study investigated the effects of combination of insulin-like growth factor 1 (IGF1), coenzyme Q10 (CoQ10), and melatonin (MT) on development of bovine oocytes, embryos and heat stressed blastocysts.
In this study, IGF1, CoQ10 and MT were added to bovine oocyte in vitro maturation (IVM) solution and bovine embryo in vitro culture (IVC) solution. The developmental ability, level of reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) of bovine oocytes were detected. The effects of heat stress and combined supplementation on the developmental ability and apoptosis level of bovine IVF blastocysts were determined, and the mRNA expression levels of embryo quality related genes were detected by RT-qPCR.
The results showed that the combination of IGF1, CoQ10 and MT (ICM group) significantly increased oocyte maturation rate ((90.40 ± 2.06)% vs. (65.41 ± 0.63)%), cleavage rate ((93.33 ± 1.96)% vs. (59.77 ± 2.93)%) and blastocyst rate ((51.43 ± 5.34)% vs. (26.92 ± 3.24)%)) (P< 0.05) compared with the non added (CT-0) group. In the ICM group, the ROS level of bovine oocytes was significantly decreased and the ΔΨm of bovine oocytes was significantly increased (P < 0.05). Compared with the heat stress (HS) group, the combination of IGF1, CoQ10 and MT (ICM+HS group) significantly increased expanding rate ((62.00 ± 2.97) % vs. (30.77 ± 8.66) %, P< 0.05) of heat stressed blastocyst, inhibited apoptosis of heat stressed blastocyst cells, and increased mRNA expression levels of IGFBP3, ATP1A1, DSC2, and IFNT2 (P< 0.05) of heat stressed blastocyst.
In summary, the combination of IGF1, CoQ10 and MT can effectively enhance developmental ability, reduce the ROS level and increase the ΔΨm of bovine oocytes. Heat stress reduced blastocyst expanding rate, promoted apoptosis of bovine IVF blastocyst cells and damaged blastocyst quality, while the combination of IGF1, CoQ10 and MT alleviated the damage form heat stress.
