Distance between mRNA and nuclear envelope. (A) Region of interest view of the equatorial plane of Fig. 5 A. The closest distance between the circled mRNA and an NPC is close to 2 µm. The arrowhead points at a presumably closer NPC. (B) Rotated view of a 3D projection of the same mRNA. A NPC is found in close proximity to the mRNA two planes above. Arrowhead points to the same NPC as in A showing that the NPC is located one plane above the mRNA in A. (C) For all identified mRNA signals the closest lateral nuclear pore is identified and the distance measured. Most mRNAs (>80%) are further than 0.5 µm away from the nuclear rim. (D) For all identified mRNAs the shortest distance to a nuclear pore is calculated in 3D. At least 60% of mRNAs are within 0.5 µm of a nuclear pore and no more than 15% of mRNAs are further than 1 µm from a nuclear pore. The data are standard deviations per bin over 12 cells in which >51,000 distances between mRNAs and NPCs were measured.