Transcripts associated with the plus-ends of microtubules are enriched in the MB transcriptome. (A) Comparison of MB-associated mRNA with RNAs enriched in neuronal projections of mouse neuronal cells. Genes were binned into MB-localized RNAs and non-MB-localized RNAs. Neurite RNA enrichment values (neurite RNA/soma RNA, log₂) from previously published data were then calculated for the mouse orthologs of all genes, and the distributions of enrichment values were compared between bins. P values were calculated using a Wilcoxon rank-sum test. (B) As in A, genes were binned according to their MB RNA enrichment. Using a previous published comparison of the apical and basal compartments of epithelial cells, basal enrichment values (basal RNA/apical RNA, log₂) were calculated for all genes and the distributions of enrichment values were compared between bins. P values were calculated using a Wilcoxon rank-sum test. (C)NET1 RNA enrichment in human midbodies compared with whole cells (left) and mouse neurites compared to cell bodies (right). Scale bars: 10 μm. Inset scale bars: 2 μm. (D) smiFISH for endogenous NET1 mRNA localization (yellow) in cells stably expressing Halo-MKLP1 (pink). Midbody is marked with an asterisk. The box indicates the area shown in a higher magnification inset. Scale bar: 5 μm. (E) Quantification of NET1 smiFISH. Transcript counts were quantified in the intercellular bridge and whole-cell areas. For each cell, the number of counts in the intercellular bridge was normalized by the number of counts in the whole cell. The median ratio for this value across all cells for the control TSG101 transcript was set to one. P values were calculated using a t test. (F) As in E, except that transcript counts in the midbody and whole cell regions were compared. P values were calculated using a t test.