Figure 2. Localization of nos to the Processes of Da Neurons.

(A–D) Class IV da neurons in semi-intact third instar larvae expressing mCD8:GFP, MCP-RFP and (A) no ms2-tagged nos mRNA (control); (B) nos-(ms2)₁₈ mRNA; (C) nos+1-(ms2)₁₈ mRNA; (D) nos+2-(ms2)₁₈ mRNA. MCP-RFP that is not bound to mRNA is sequestered in the nucleus due to an NLS in the MCP-RFP fusion protein. Arrowhead indicates the axon, as identified in lower power images. (E) Quantitation of nos*RFP particles in dendritic branches. All neurons were imaged using identical confocal settings. A merged image showing both green (mcd8:GFP) and red (nos*RFP or MCP-RFP alone) channels was enlarged and adjusted in Adobe Photoshop so that green channel was just visible. Red particles encompassed within the branches or cell body were counted and each total was normalized to the total number of dendritic termini within the field imaged (3.6×10⁴ μm²). Two independent lines analyzed for each transgene produced similar results and one line for each is shown. For each genotype, values are the average +/− standard error for 10 neurons. (F–H) Time lapse sequence of RFP-labeled nos-(ms2)₁₈ mRNA in a Class IV da neuron (only the red channel is shown). Each panel shows a single confocal section captured at the indicated time. See Supplemental Movie S2 for the complete 75 second time series. Examples of movement are indicated. Brackets illustrate movement toward and away from the cell body. Particles indicated by the bracket on the left move bidirectionally – first apart from each other, then toward each other. The pink arrow illustrates a particle that moves out of the frame. The white arrow shows a particle that crosses paths with one of the particles indicated by the bracket. The blue arrow marks a particle traveling from the cell body to a dendrite.