CENTRIN2 localizes at the centriole distal end in HYLS1 ^DG/DG RPE1 cells. (A) CENTRIN2 coverage analysis along the centriole microtubule wall (left) and CENTRIN2 position relative to the longest (LMT) and shortest (SMT) microtubules (right) in HYLS1^+/+ and HYLS1^DG/DG RPE1 cells. LMT: longest microtubule; CENT: CENTRIN2; SMT: shortest microtubule. (B) Fluorescence intensity profiles of Ac-TUBULIN and CENTRIN2 along the centriole from the proximal to the distal end at normal centrioles from HYLS1^+/+ and normal, broken and short centrioles from HYLS1^DG/DG RPE1 cells. Fluorescence intensity is the ratio relative to the maximal peak measured for Ac-TUBULIN or CENTRIN2. (C) Representative U-ExM images of centrioles (Ac-TUBULIN) and CENTRIN2, POC5, C2CD3, and TALPID3 of Hyls1^+/+ and Hyls1^DG/DG G2-phase arrested RPE1 cells. (D) Representative U-ExM images of centrioles (Ac-TUBULIN) and CENTRIN2 of Hyls1^+/+ and Hyls1^DG/DG G2-phase arrested RPE1 cells showing centriolar fragments capable of duplicating. Data are represented as mean ± SEM. Statistical significance was determined using an unpaired two-tailed Student’s t test with Welch’s correction for CENTRIN2 coverage over centriole and CENTRIN2 length. One-way ANOVA with Tukey’s multiple comparisons was used to test centriole microtubule length analysis. (**) P < 0.01, (***) P < 0.001, (****) P < 0.0001. Only significant results are indicated. Scale bar is 250 nm in C and D. Arrows (D) point to assembling procentrioles.