J. Representative immunofluorescence staining of ER (CLIMP63, green) and lysosomes (TMEM192-HA, red) in chondrocytes with indicated genotypes (ctrl=wild type) treated with FGF18 (50 ng/mL for 16h). BafA1 was used at 100 nM for 4 hours to inhibit lysosomal degradation. Quantification of relative CLIMP63 fluorescence into TMEM192-HA positive vesicles. N=3 biological replicates; n=21 cells were analyzed. Mean +/- standard error of the mean (sem). Paired Student's T-test NS= not significant. Scale bar 10 μm and 1.3 μm (higher magnification boxes). 