Expression of two surface antigens and paternal glucose-phosphate isomerase in polyploid one-cell mouse eggs

Cleavage in 1-cell mouse eggs was suppressed by continuous treatment with cytochalasin B for 3 or 4 days. During this period the eggs became highly polyploid and showed gene products not found before the 6- to 8-cell stage in control embryos. These polyploid 1-cell eggs (a) reacted with two monoclonal antibodies (anti-SSEA-1 and ECMA 7), which recognize stage-specific surface antigens, and (b) expressed the paternal form of the enzyme glucosephosphate isomerase. The molecular development of early mouse embryos, therefore, seems to progress stage specifically even without cleavage occurring.