F-actin is associated with NMIIB and Tmod1 in human enucleating erythroblasts. (A) Extended-focus projections of confocal Z-stacks of human bone marrow erythroblasts at various stages of enucleation immunostained for NMIIB and GPA, phalloidin for F-actin, and Hoechst for nuclei. (B) Confocal single optical sections of human bone marrow erythroblasts at various stages of enucleation immunostained for Tmod1 and GPA, phalloidin for F-actin, and Hoechst for nuclei. Arrows, bright F-actin spots at the rear of the translocating nucleus and in the reticulocyte. Bar, 4 µm.