Distinct regions of RNA transport directionality.

<p>Oocytes expressing PA-mCh-MCP were microinjected with VLE-MS2 RNA. (A) Prior to activation of PA-mCh-MCP in live oocytes (t = 0), minimal fluorescence is observed. The activation point is shown by the small white dot and the oocyte nucleus is outlined in white. Scale bar, 20 µm. (A′) By 7 s after activation of PA-mCh-MCP, robust fluorescence (red) is evident at and around the activation point (white dot). (A″–A′″) By 240–480 s after activation, PA-mCh-MCP tethered to RNA can be visualized asymmetrically around the activation point. (A′″) The four collection quadrants are indicated by white circles surrounding the activation point: V and A indicate the collection quadrants on the vegetal and animal sides of the activation point, respectively. L and R indicate the collection quadrants on the left and right sides. (B–C) After activation of PA-mCh-MCP in (B) the upper vegetal cytoplasm (Region 2) or (C) the lower vegetal cytoplasm (Region 3), corrected fluorescence intensities in the V (black) and A (grey) quadrants were plotted over time. (D, E) The ratios of V∶A (red) and L∶R (blue) intensities for oocytes activated in (D) the upper vegetal cytoplasm (Region 2) and (E) the lower vegetal cytoplasm (Region 3) were plotted over time.