This paper describes the developmental potential of blastomeres isolated 4-cellembryos in mice.Four-cell embryos were collected from superovulated CF #1 females which weremated with C57BL/6 males. Zona pellucidae were removed in Hanks solution containing 0.2% pronase. After removal of zona pellucida, 4-cell embryos were separeatedinto individual blastomers by pipetting in Ca⁺⁺and Mg⁺⁺free Hanks solutioncontaining 0.02% EDTA. Separated blastomeres (one-quarter embryos) were culturedin drops of M16 medium covered with paraffin oil at 37°C in an atmosphere of 5% CO₂, 95% air for 72 hours. Four one-quarter embryos developed to blastocysts were transferred into rightuterine horn of CF#1 recipients on Day 4 or 5 pseudpregnancy, and 4 normalblastocysts of CF#1 strain cultured from 4-cell stage were transferred intoleft uterine horn of the same recipient.The results were as follow: 1) The proportion of one-quater embryos developed intoblastocysts were 79/124 (63.7%). 2) By transfer of one-quater embryos developed toblastocysts, the proportion of implantation sites and live fetuses were 6/24 (25.0%) and 0/24 (0%). On the other hand the propotion of implantation sites and livefetuses were 19/24 (79.2 %) and 14/24 (58.3%).

抄録全体を表示

Our previous finding of the incorporation of ¹⁴C-leucine and¹⁴C -glutamic acid in rat eggs has suggested that the incorporationof amino acids in rat eggs is mediated by oxidation of the intermediarymetabolite as an energy source. In this study, the incorporationof ¹⁴C-leucine and ¹⁴C-glutamic acid under an anaerobic conditionwas examined using eggs of the 1-cell (unfertilized), 2-celland early blastocyst stages. The incorporation of these aminoacids under an anaerobic condition was lower either in the absenceof a substrate or in the presence of lactate, compared to the previouslyreported result under an aerobic condition. These resultssuggested that the incorporation of amino acids in rat eggs is mediatedby oxidation of the intermediary metabolite as an energysource.

抄録全体を表示