Tax dynamic trafficking between nuclear bodies and centrosome in human fibroblasts. Human fibroblasts IMR90 cells were cotransfected with Tax tagged with a green-to-red photoconvertible fluorescent protein, Dendra2 (2 μg) and YFP-Centrin (0.5 μg). Irreversible photoconversion from green to red was performed on selected nuclear body (A) or on juxta-nuclear concentrates of Tax-Dendra2 (B) 4 hours after transfection using a 405 laser. The white arrows indicate centrosomal aggregates colocalizing with YFP-centrin. Cells were imaged using a LSM710 confocal laser microscope in the green (lane 1), red (lane 2), and yellow (lane 3) channels before and after photoconversion. Original yellow color was replaced by cyan for better clarity. Scale bar, 10 μm.