Development potential of mouse embryos conceived in vitro and cultured in ethylenediaminetetraacetic acid with or without amino acids or serum.

Mouse ova were inseminated in vitro in modified Earle's balanced salts solution (EBSS) supplemented with 10 or 100 microM EDTA and 4 mg/ml BSA. After 4 h exposure to sperm, the ova were transferred to five different culture conditions based on albumin-free EBSS supplemented with 10 microM EDTA minus or plus amino acids, or with 100 microM EDTA minus or plus amino acids, or with human cord serum. After 44 h of culture, four-cell embryos from each culture group were transferred in cohorts of five into the left oviduct of pseudopregnant recipients (13-16 per culture condition). Two-cell embryos developed in vivo were similarly transferred to a separate group of recipients to serve as controls. The pregnancy rates following transfer of embryos cultured in 10 microM EDTA minus or plus amino acids or in 100 microM EDTA plus amino acids (38%, 43%, and 50%, respectively) were not significantly different from those of the in vivo control group (43%). The pregnancy rates following transfer of embryos cultured in 100 microM EDTA plus amino acids (21%) or plus cord serum (8%) were significantly lower (p less than 0.01) than those of the other groups. The overall yield of fetuses from total embryos transferred was significantly higher (p less than 0.01) for the groups developed in 100 microM EDTA plus amino acids (29%) and in vivo (26%) compared with embryos developed in 10 or 100 microM EDTA with no amino acids, 10 microM EDTA plus amino acids, or 100 microM EDTA plus cord serum (15%, 15%, 9%, and 3%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)