RCAN2 localises to centrioles. (A) qPCR of two giantin zebrafish mutant lines (Q2948X and X3078) compared with wild-type sibling controls shows that rcan2 is strongly upregulated relative to the housekeeping gene actb1. In contrast, hprt1 and gapdh are not upregulated. (B) Endogenous RCAN2 (red) localises to centrioles labelled with γ-tubulin (green) in hTERT-RPE1 cells. Scale bar: 10 μm. (C) RCAN2 is frequently (25±11%, n=3 independent experiments) found concentrated at the mother centriole (from which the cilium extends) as shown by acetylated tubulin labelling of the ciliary axoneme (arrowhead). Where only one puncta of RCAN2 labelling is found (asterisk; 7±3% of cells, n=3 independent experiments), a ciliary axoneme is always found extending from this centriole. (D) The distal appendage protein CEP170 is associated with the brighter of the two RCAN2-positive centrioles (arrowhead) as well as with single centrioles positive for CEP170 (asterisk). Boxes are 5×5 µm; >50 cells were analysed in each of the independent experiments in B-D.