Localization analysis of Net1 mRNA. (A) smiFISH for endogenous NET1 mRNA localization (red) in human epithelial cells. As a nonlocalized control, transcripts encoding an exogenous Firefly luciferase are also visualized. (B) Quantification of NET1 RNA localization along the apicobasal axis of epithelial cells. (C) Quantification of MB-localized Net1 UTR-containing reporter transcripts. In all samples, reporter transcript counts in midbodies and whole cells were quantified and the ratio of counts between the two locations is reported. These ratios were normalized by setting the value for the control reporter transcript lacking 3′ UTR additions to one. P values were calculated using a t test.