In vitro culture systems are required for many biotechnological and assisted reproductive technologies. In order to perfect the conditions, the effect of genetic background was evaluated in the in vitro development of embryos from CD-1 and CB6F1 mice in potassium simplex optimized medium supplemented with amino acids (KSOMAA). Presumptive zygotes were recovered from superovulated and mated females (19-20 h post-hCG injection). Two-cell stage block, morula (M), expanded blastocyst (EB), and completely hatched blastocyst (CHB) rates and total cell count were compared in the two mouse strains. The development of CD-1 vs. CB6F1 embryos to 2-cell (98% vs. 96%) and to 3- to 8-cell (89% vs. 93%, respectively) were not significantly different (p > 0.05). However, significant differences were detected in the proportions of CD-1 vs. CB6F1 embryos reaching later stages (79% vs. 91% for M (p < 0.01), 65% vs. 77% for EB (p < 0.05), and 34% vs. 49% for CHB stages (p < 0.01), respectively). The results showed that the genetic background of mouse embryos has a significant effect on in vitro developmental potential to late pre-implantation stages. Nevertheless, zygotes obtained both from CB6F1and CD-1 mouse strains have been cultured successfully in KSOMAA in 5% CO2 in air at 37 °C.

In vitro culture systems are required for many biotechnological and assisted reproductive technologies. In order to perfect the conditions, the effect of genetic background was evaluated in the in vitro development of embryos from CD-1 and CB6F1 mice in potassium simplex optimized medium supplemented with amino acids (KSOMAA). Presumptive zygotes were recovered from superovulated and mated females (19-20 h post-hCG injection). Two-cell stage block, morula (M), expanded blastocyst (EB), and completely hatched blastocyst (CHB) rates and total cell count were compared in the two mouse strains. The development of CD-1 vs. CB6F1 embryos to 2-cell (98% vs. 96%) and to 3- to 8-cell (89% vs. 93%, respectively) were not significantly different (p > 0.05). However, significant differences were detected in the proportions of CD-1 vs. CB6F1 embryos reaching later stages (79% vs. 91% for M (p < 0.01), 65% vs. 77% for EB (p < 0.05), and 34% vs. 49% for CHB stages (p < 0.01), respectively). The results showed that the genetic background of mouse embryos has a significant effect on in vitro developmental potential to late pre-implantation stages. Nevertheless, zygotes obtained both from CB6F1and CD-1 mouse strains have been cultured successfully in KSOMAA in 5% CO2 in air at 37 °C.