Miyoshi K, Niwa K
Division of Animal Science and Technology, Faculty of Agriculture, Okayama University, Japan.
Zygote. 1997 Feb;5(1):67-73. doi: 10.1017/s0967199400003579.
Rat 1-cell embryos, recovered from naturally mated females, were cultured in a chemically defined medium (mR1ECM). When examined after 24, 56, 64 and 80 h of culture, embryos developed to the 2-cell (100%), 4-cell (93%), 4-cell to 8-cell (97%) and > or = 8-cell (95%) stages, respectively. When 0.4 M phosphate (NaH2PO4) was added to the medium after 0, 24, 56 and 64 h of culture, percentages (0-67%) of embryos that developed to the blastocyst stage after 115 h of culture were lower than that (86%) in the medium without phosphate. However, addition of phosphate after 80 h of culture accelerated blastocyst formation; a significantly higher percentage (94%) of blastocysts was obtained after 110 h of culture in this medium compared with when phosphate was not added (67%). When phosphate was added to the medium after 64 h, almost all (97%) 8-cell embryos developed to the blastocyst stage by 100 h of culture but development of 4-cell to 7-cell embryos was inhibited (22-63%). Acceleration of blastocyst formation was caused by addition of phosphate rather than by the exchange of the medium. The stimulatory effect of phosphate on embryo development was observed at concentrations of 0.1-1.2 mM. The mean numbers of cells (54.5-60.9 cells) in blastocysts examined after 115 h of culture were increased by the addition of 0.4-1.6 mM phosphate at 80 h as compared with blastocysts from cultures without phosphate (46.6 cells).
从自然交配的雌性大鼠中获取1-细胞期胚胎，在化学成分明确的培养基（mR1ECM）中培养。在培养24、56、64和80小时后进行检查时，胚胎分别发育到2-细胞期（100%）、4-细胞期（93%）、4-细胞至8-细胞期（97%）和≥8-细胞期（95%）。在培养0、24、56和64小时后向培养基中添加0.4M磷酸盐（NaH₂PO₄），培养115小时后发育到囊胚期的胚胎百分比（0-67%）低于未添加磷酸盐的培养基中的百分比（86%）。然而，在培养80小时后添加磷酸盐可加速囊胚形成；与未添加磷酸盐时相比，在该培养基中培养110小时后获得的囊胚百分比显著更高（94%）。当在64小时后向培养基中添加磷酸盐时，几乎所有（97%）的8-细胞胚胎在培养100小时时发育到囊胚期，但4-细胞至7-细胞胚胎的发育受到抑制（22-63%）。囊胚形成的加速是由添加磷酸盐而非培养基的更换引起的。在0.1-1.2mM的浓度下观察到磷酸盐对胚胎发育的刺激作用。与未添加磷酸盐培养的囊胚（46.6个细胞）相比，在80小时添加0.4-1.6mM磷酸盐后，培养115小时检查的囊胚中的平均细胞数（54.5-60.9个细胞）有所增加。
