Fig. 6

Map1a KD perturbs microtubule (MT) organization through disruption of MT polymerization. A Using IF analysis, effective KD of Map1a (top left panel) perturbed the organization of MTs across the Sertoli cell cytoplasm since microtubules no longer stretched across the entire cell cytoplasm as noted in control cells, but retracted from cell peripheries and wrapped around the cell nuclei. Such changes were noted in the isoforms of MTs, including detyrosinated α-tubulin and acetylated α-tubulin, representing the stabilized forms of MTs; and tyrosinated α-tubulin (the dynamic, un-stabilized form of MTs). The distribution of dynein 1, CAMSAP2, Kif15, and EB1 were also perturbed following Map1a KD. Scale bar, 30 µm, which applies to other micrographs. B IB analysis illustrates the effectiveness of Map1a KD, without affecting other MT isoforms, MT regulatory proteins and cytoskeletal proteins after Map1a KD. C Results of a biochemical assay that monitored MT polymerization activity of the Sertoli cell lysates from Map1a KD cells versus control cells. Importantly, the effective KD of Map1a (see bottom panel) did not affect the expression of the MT isoforms, but it considerably inhibited MT polymerization. D Composite data of the MT polymerization assay illustrates the effective KD of Map1a that led to a considerable disruption of MT polymerization. ***, P < 0.005, by paired Student's t-test, compared to the corresponding control (Ctrl)