RhoA-dependent actin turnover in megakaryocytes and erythroblasts. MKs and ERYs were transduced with lentiviral vector encoding mCherry-tagged LifeAct on days 3 and 4 of in vitro culture, respectively. MKs were sorted on day 5 on the expression of CD41a CD42 and mCherry. ERYs were sorted on mCherry expression on day 7 of culture. (A) MKs and ERYs either control or pretreated for 24 hours with Y27632 were assessed by FRAP. MKs were analyzed on day 6 of culture and ERYs on day 8 of culture under a confocal microscope for the fluorescence recovery of mCherry at the cleavage furrow/midzone. Representative montage images of fluorescence recovery are shown. A white box marks the bleached area. (B) At least 2 FRAP curves were obtained from each cell analyzed. At least 5 individual cells were analyzed and the resulting FRAP curves were fitted. An example of the FRAP recovery curve is presented. (C) Fluorescence recovery kinetics of mCherry-tagged LifeAct in control and Y27632-treated MKs and ERYs at the cell cortex. A representative FRAP recovery kinetics is shown here.