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Fig. 6 Paxillin overexpression increases laminin organization and ameliorates dystrophy in dag1 morphants.
(A–C) Anterior left, dorsal top, side-mounted, 1 dpf embryos antibody stained for paxillin (white). (A) Paxillin concentrates at the MTJ in both untreated (not shown) and NAD+-treated controls (white arrows). (B) Paxillin is less concentrated at the MTJ in dag1 morphants (white arrowheads). (C) NAD+ rescues the disrupted concentration of paxillin at the MTJ in dag1 morphants (white arrows). (D-E) Anterior left, dorsal top, side-mounted, 2 dpf embryos stained with laminin-111 antibody (white). Numbered panels are 3-D reconstructions. (D) dag1 morphant laminin-111 appears within myotomes, and the MTJ BM is poorly aligned medially laterally and contains holes (white arrowheads). (E) In contrast, paxillin overexpression (green) in dag1 morphants reduces laminin-111 within myotomes and enhances organization of laminin-111 at the MTJ BM (white arrows). (F-G) Anterior left, dorsal top, side-mounted, 3 dpf embryos stained for actin (phalloidin, white). (F) dag1 morphant with detached fibers (white arrowhead). (G) Transgenic overexpression of paxillin (green) in dag1 morphants reduces fiber detachment. (H) Paxillin overexpression significantly reduces the frequency of fiber detachment in dag1 morphants; *p<0.05. (I) Model of cell adhesion at the MTJ in response to Nrk2b pathway activation via exogenous NAD+ or paxillin overexpression. Scale bars are 50 micrometers.