Enucleation of human erythroblasts involves non-muscle myosin IIB. (A) A schematic presentation of rod fragments: ARF296 (for myosin IIA) and BRF305 (for myosin IIB). (B) Confocal microscopy of CFU-E transfected by pEGFP-ARF296 and pEGFP-BRF305. Scale bar = 10 μm. (C) CFU-E were transfected with pEGFP-ARF296 and pEGFP-BRF305. After 24 hours of incubation, the dead cells were removed and then incubated in the erythroid medium. After culture for the indicated period, the cells were harvested, counted and GPA⁺/GFP⁺ cells were analyzed by flowcytometry. Representative data for 2 independent experiments are shown. (D) Mature day 10 erythroblasts were transfected with pEGFP-ARF296 and pEGFP-BRF305. GPA⁺/GFP⁺ cells were sorted and cultured in the erythroid medium. After culture for the indicated period, the cells were harvested and stained with May-Grünwald-Giemsa. An aliquot of the cells were observed by confocal microscopy. Scale bar = 10 μm. (E) GPA⁺/GFP⁺ cells were cultured in the erythroid medium. At the indicated period, the cells were harvested and counted. Results are presented as the mean ± SD of 3 independent experiments. *P < .05 and **P < .01.