Tetraploid Mouse Embryos produced by Cytochalasin B during Cleavage

IT has been reported that cytochalasin B can prevent cytokinesis without influencing nuclear division 1 . Cells undergoing mitosis in the presence of cytochalasin B become binucleate and occasionally, with prolonged incubation, multinucleate 1–3 . Treated cells generally resume cleavage upon removal from cytochalasin and reculturing. It has been shown that many of the binucleate cells produced in a BHK21 cell line will develop as tetraploids upon reculturing in fresh medium 4,5 . Here I report the treatment of cleaving mouse eggs with cytochalasin and the establishment of tetraploidy in mouse embryos.