Changes in fucosyl-glycopeptides during early post-implantation embryogenesis in the mouse

Six-day to 12-day mouse embryos were dissected and radiolabelled by culture in the presence of [3H]fucose. The radiolabelled embryos were extensively digested with Pronase. The resulting glycopeptides were analysed by Sephadex G-50 column chromatography. Glycopeptides from 6-day-old embryos were separated into two main peaks: one eluted near the excluded volume, the other in a well-retarded position. This elution profile was similar to that observed with glycopeptides prepared from embryonal carcinoma cells. The relative amount of the high-molecular-weight glycopeptides decreased during embryonic development and particularly around day 9. Glycopeptide elution profiles from 10-day embryos, or isolated organs of 12-day embryos, were indistinguishable from those obtained from differentiated teratocarcinoma-derived or adult cells. At least 30% of the large molecular weight glycopeptides appear to be located at the cell surface.