Fig. 7

Map1a KD perturbs actin organization through disruption of actin polymerization and filament bundling activity. A Effective KD of Map1a as noted by IF analysis led to the truncation of actin filaments across the Sertoli cell cytoplasm, distinctively different from control Sertoli cells. These changes appeared to be the result of the disruptive distribution of Arp3 (a branched actin polymerization-inducing protein) and Eps8 (an actin barbed-end capping and bundling protein) in Sertoli cells. Also, vimentin-based intermediate filaments and septin7-based cytoskeleton were also grossly perturbed in Map1a silenced cells versus control cells. Data shown here are representative findings from an experiment and n = 3 experiments yielded similar results. Scale bar, 20 µm, and 15 µm in inset; which apply to other corresponding micrographs in the same panel. B Effective KD of Map1a in Sertoli cells as noted by IB analysis did not affect the steady-state protein levels of several actin regulator proteins and other structural/cytoskeletal proteins, supporting the notion that there were no off-target effects of Map1a KD. C Using a biochemical assay to assess actin polymerization and actin-bundling activity (F-actin), Map1a considerably perturbed actin polymerization and the formation of F-actin. Composite data of these findings are shown in the bar graphs on the right panel that illustrate that Map1a KD led to effective disruption of actin polymerization. Each bar is a mean ± SD of n = 3 experiments. **, P < 0.01; ***, P < 0.005 by paired Student’s t-test