Introduction of a heterologous nucleus into enucleated cytoplasms of cultured mouse L-cells.

Mouse L-cells exposed to cytochalasin B undergo random nuclear protrusion and, occasionally, total enucleation. The anucleate cell remains viable for several days. Chick erythrocytes were fused to L-cells with inactivated Sendai virus. The resulting hybrids, containing one or more erythrocyte nuclei in addition to the L-cell nucleus, were treated with cytochalasin B. Through the process of random enucleation, the L-cell nucleus was extruded from some hybrid cells while the erythrocyte nucleus was retained in the hybrid. In other experiments, chick erythrocytes were fused directly to enucleated L-cells. The result in both instances is the introduction of an erythrocyte nucleus into L-cell cytoplasm. The erythrocyte nucleus swells and the hybrid cell is capable of incorporating radioactive uridine.