Immunofluorescence, gene expression and Western blot analysis of beta-tubulin of chondrocytes cultured at 1 g or on the RPM. A–E: Beta-tubulin immunofluorescence of chondrocytes cultured at 1 g or on the RPM for different times (30 min ( A ), 2 h ( B ), 4 h ( C ), 16 h ( D ), 24 h ( E )). Control cells showed a similar distribution of β-tubulin, while chondrocytes exposed to the RPM exhibited a perinuclear accumulation of β-tubulin (orange arrows). F: Gene expression of TUBB6 was significantly elevated after 0.5 h, but did not change significantly during the rest of the 24 h of culturing on the RPM. G: Western blot analysis of ß-tubulin protein: The protein content was significantly elevated after 4 h RPM exposure. After 24 h no change was detectable. Data are given as mean ± standard deviation; #P