Fig. 2

Hypoxia leads to a more ordered actin cytoskeleton. SH-EP cells were grown in normoxia (20 % O₂) or hypoxia (1 % O₂) for 72 – 96 h. Coverslips were fixed with 4 % PFA and stained with TRITC-phalloidin and DAPI. Single z-plane images were obtained by confocal microscopy. Linear feature detection software was used to quantitate actin cytoskeletal organization. a-d Representative linear detection after 72 h ± hypoxia. Hypoxia visibly increases the number of actin filament bundles known as stress fibres (b vs. d). Scale bar = 50 μm, or 5 μm in inset. e Hypoxia increases mean actin filament bundle width at 72 h. f Hypoxia increases total actin filament length per cell number (AFLC) and (g) per cell area (AFLA). Data is mean ± SEM (n = 3). 650+ cells analysed per timepoint. ** P <0.01, *** P <0.0001 (t-test). ^†AFLA is dimensionless, with [length (pixels)]/[area (pixels)]