Finding a better mouse model for quality control and research studies in the IVF laboratory

Abstract

Objective Since the strain of mouse embryos routinely used for quality control in IVF laboratories almost always have >90% blastocyst development, possibly due to improved culture conditions, it is very difficult to detect negative effects of media that would that would otherwise affect human embryo development. The aim of this study was to find a strain of mouse embryos that would be more sensitive to culture changes for use as a marker for quality control as well as for research studies. Design Prospective study Materials and methods One-cell embryos from B6D2F1 & B6C3F1 Hybrid mice (Strain 1) and from C57BL-6N mice (Strain 2) were used for this study. Embryos were thawed and cultured in different types of media: (1) One-Step medium, (2) One-Step medium with IGF-1, and (3) One Step medium with insulin. All embryos were cultured in an EmbryoScope incubator at 37°C, 5.5% CO2 and 6% O2 for 6 days. The blastocyst formation rate was calculated as the number of blastocysts per embryos cultured for each group and compared statistically using a Chi-squared test. Results The data showed that Strain 2 embryos had significantly lower blastocyst development rates than Strain 1 embryos in One-Step medium routinely used in IVF culture (Table 1). Furthermore, when testing the effect of adding IGF-1 or insulin to the media, Strain 2 embryos showed more pronounced changes in blastocyst development rates compared to Strain 1. The insulin supplemented media resulted in significantly lower blastocyst development rate for both strains. Conclusions The C57BL-6N strain of mouse embryos appears to be a better model for detecting subtle changes in culture conditions since it is more sensitive than the B6D2F1 & B6C3F1 Hybrid strain. Ongoing studies are aimed at assessing if there are any changes associated with time-lapse morphokinetics. Disclosures Nothing to disclose Funding None