Building a better mouse embryo assay: effects of mouse strain and in vitro maturation on sensitivity to contaminants of the culture environment

The aim of this study is to compare the sensitivity of the standard one-cell mouse embryo assay (MEA) to that using in vitro-matured oocytes from hybrid and outbred mice. The study was done by culturing embryos in the presence or absence of two concentrations (0.0005 or 0.001 % v/v) of Triton X-100 (TX100). Embryonic development, blastocyst cell numbers (total and allocation to the trophectoderm [TE] and inner cell mass [ICM]), and blastocyst gene expression were evaluated. Neither concentration of TX100 affected (P > 0.05) cleavage, blastocyst development, or hatching in one-cell embryos from BDF1 mice. However, all cell number endpoints were reduced (P