TUB1 mRNA level is comparable to TUB3 in WT cells and unchanged in tub3Δ cells. (a) TUB1 (red) and TUB3 (blue) mRNA levels as a percentage of total expression in WT cells. (b) Transcript levels of TUB1, TUB2, and TUB3 in WT, tub3Δ, Tub1-only, and Tub3-only cells. (c) 3′ UTR–specific transcript levels originating from the TUB1 locus (red background) or TUB3 locus (blue background) as a percentage of total expression (cell type is indicated above the bars). For this assay, a forward primer and probe, both with 100% homology to TUB1 and TUB3, were coupled with reverse primers specific to the 3′ UTR of either locus. For panels a and b, n = 6 independent cultures and RNA/cDNA preps; for panel c, n = 4 independent cultures and RNA/cDNA preps. In panel b, TUB1 expression was repeated four times with the predesigned TaqMan assay and twice with the custom assay and the results combined, since expression was similar with either probe/assay. In all panels, graphs show mean ± SEM; n.s., not significant; **, P ≤ 0.01 by unpaired, two-tailed Student’s t test.