EVALUATION OF COCULTURE AND ALTERNATIVE CULTURE SYSTEMS FOR PROMOTINGIN-VITRO DEVELOPMENT OF MOUSE EMBRYOS

The goal of this study was to compare mouse embryo development in a de fined synthetic medium (human tubal fluid) against the same medium sup plemented with a defined synthetic serum (SS), co-culture on human tub al epithelium (TECC), and culture on human fibronectin (FN) with and w ithout SS, After 48 h, TECC, SS and FN + SS cultures demonstrated acce lerated development with > 70% achieving greater than or equal to 8-ce ll stage, After 72 h, these culture conditions also significantly incr eased the proportion of embryos reaching the blastocyst stage but only TECC significantly increased the number of hatching blastocysts. Nucl ei of the trophectoderm of unhatched and hatched blastocysts were stai ned with propidium iodide before fixing and labelling both the trophec toderm and inner cell mass with bisbenzimide, Blastocysts from the TEC C contained a significantly higher total cell number (TCN) and trophec toderm and inner cell mass cell numbers than all other groups. These f indings indicate equivalent improvements in mouse embryo development t o the blastocyst stage in response to TECC, SS and FN and an enhanced number of cells and rate of hatching found only with TECC.