Fixation of Carbon Dioxide by Pre-Implantation Mouse Embryos in Vitro and the Activities of Enzymes Involved in the Process

The incorporation of fixed carbon from carbon dioxide into mouse embryos was greatest in eight-cell embryos which developed into blastocysts during a 24-hr culture period and was four to five times greater than the incorporation into two-cell embryos cultured for a similar period. The net accumulation of labelled products in the culture medium was greatest during the culture of the morula stage to the blastocyst over 24 hr.