Rho expression during MK differentiation. CD34⁺ cells purified from blood leukapheresis were cultured in the presence of TPO. At day 6 and day 12 of culture, cells were dually stained with a VWF polyclonal antibody (green) and an anti-Rho mAb (red). (A) Rho was uniformly distributed all over the cytoplasm of mature MKs with a slight reinforcement along the plasma membrane (i-ii). Rho was distributed clearly along the plasma membrane in another MK suggesting an activation site (iii-iv). In MKs forming PPTs, Rho was localized all over the cytoplasm (v-vi). Bars represent 5 μm. (B) The level of Rho was studied by Western blotting using Hsc70 as the control. At day 3, Western blots were performed on total culture. In contrast, at days 6, 9, and 12, Western blots were performed with CD41⁺MKs.