CAN MATRIGEL SUBSTITUTE FOR VERO CELLS IN PROMOTING THE IN-VITRO DEVELOPMENT OF MOUSE EMBRYOS

The influences of Vero cells and the basement membrane substratum for these cells (Matrigel(R)) on the rate of hatched blastocyst formation from mouse zygotes in vitro were compared. Zygotes obtained from C57BL /6XBALB/c F1 females pretreated with pregnant mare's serum gonadotroph in/human chorionic gonadotrophin mated with BDF1 males were cultured ( 120 h) in human tubal fluid medium supplemented 0.5% with bovine serum albumin, The rates of early hatching and hatched blastocyst formation at 96 and 120 h of culture were expressed as the percentage of 2-cell embryos visualized after the initial 24 h, The rate of total blastocy st formation did not differ between treatment groups, However, <10% of embryos cultured for 96 h in medium alone advanced to the hatching st age compared with 35-40% of blastocysts cultured with Vero cells or wi th Matrigel alone. Similarly, by 120 h of culture, only 20% of embryos cultured in medium alone developed to hatching or hatched blastocysts compared with >70% for those embryos co-cultured with Vero cells or w ith Matrigel, In conclusion, Vero cells improved the rate of developme nt of mouse embryos to hatched blastocysts during serum-free culture, Similar improvements were seen in the presence of Matrigel alone; Matr igel is the basement membrane substratum used for the Vero cells, Furt her studies on the means whereby Matrigel promotes early embryonic dev elopment (e.g. appropriate combination of basement membrane-associated growth factors) may lead to a safe, defined medium preparation for th e stimulation of in-vitro development of human embryos.