Superovulation, in vitro fertilization (IVF) and in vitro development (IVD) protocols for inbred BALB/cJ mice in comparison with outbred NMRI mice

Abstract

Purpose: To study assisted reproductive technology (ART) protocols including superovulation, in vitro fertilization (IVF) and in vitro development (IVD) for BALB/cJ mice in comparison with a common ART protocol for NMRI mice. Methods: Adult NMRI and BALB/cJ mice were superovulated using a 48 h G-interval. In order to find a more suitable G-interval for the BALB/cJ strain, G-intervals including 44, 46 and 50 h were also examined. Superovulation rates were recorded in all groups. IVF rate of BALB/c oocytes in T6 and mHTF media were compared. IVD rates of BALB/cJ zygotes in mHTF, T6 and G1V5/G2V5 media were compared. In addition, IVF and IVD rates of BALB/cJ and NMRI oocytes were compared in T6 medium during IVF-IVD procedures. Results: In BALB/cJ mice the highest superovulation rates were observed with 44-46 h G-intervals. However, with a 48 h G-interval, superovulation rates were significantly lower in BALB/cJ compared to NMRI mice (p\0.05). mHTF medium significantly increased in vitro fertilization of BALB/cJ oocytes compared to T6 medium (p\0.05). Fertilization rate of NMRI oocytes was significantly higher than BALB/cJ oocytes in T6 medium (p\0.05). The BALB/cJ embryo IVD was significantly higher in G1/G2 medium compared to mHTF and T6 media (p\0.01). Conclusions: Superovulation with 48 h G-interval and using T6 during all in vitro procedures produces embryos more efficiently for NMRI mice than for BALB/cJ mice. For BALB/cJ mice, a protocol including superovulation with a 44-46 h G-interval, using mHTF during IVF and G1V5/G2V5 medium during IVD, may improve in vitro embryo production. © Japan Society for Reproductive Medicine 2012.