Movie S6.

Transfer of β-actin–MBS mRNA between heterologous donor and acceptor cell types. Acceptor U2OS cells and donor β-actin–MBS MEFs expressing tdMCP–GFP (green) were cocultured for 2.5 h and then were imaged with a 150× objective, as detailed in Materials and Methods. Both cell types express TagRFP-T-ps (magenta). For this movie, cells were imaged at 10-s intervals, 11 z-sections of 0.6 µm each, for 30 min. Exposure time and laser power for each wavelength were 100 ms at 50% power for the 488-nm laser and 200 ms at 30% power for the 561-nm laser. The movie shows a maximum projection of each of 121 frames (20 min, starting from frame no. 1) at 5 fps. (Scale bar: 5 µm.) Note the presence of GFP-labeled β-actin–MBS spots in the mNT.