The relationships between erythroblast denucleation and the nuclear matrix--intermediate filaments.

We present a novel approach for making cybrids. By introducing neo gene expression plasmids into rabbit reticulocytes, fusing the gene transferred reticulocytes with K562 cells and selecting in G418 selection medium, a cybrid strain K-RRneo was established. Whole mount TEM study demonstrated that after cybridization, there was a reorganization of the intermediate filaments which showed a tendency to differentiate towards reticulocytes. SDS-PAGE and western blot analysis verified the above observation, in which the vimentin blot pattern of the cybrids was similar to that of reticulocytes, but totally different from that of K562 cells. Using this model, we reaffirmed the hypothesis that the erythroid differentiation factor (EDF) might be responsible for erythroid differentiation as well as the initiation of denucleation.