Fig. 5

Paxillin overexpression does not rescue fiber detachments caused by loss of sarcolemmal integrity. (A–B1) Anterior left, dorsal top, side mounted, 72 hpf Tg(act2b:pxn-EGFP) embryos overexpressing Paxillin-EGFP (green) stained with phalloidin (pseudocolored fuchsia) to visualize actin. (A–A1) Tg(act2b:pxn-EGFP) control embryo. Fibers remain long and Paxillin-EGFP localizes to the MTJ. (A) GFP channel only. (A1) Phalloidin and GFP channels merged. (B–B1) Tg(act2b:pxn-EGFP) embryo treated continuously with 2% EtOH from 30 to 72 hpf. Fibers detach from the MTJ. (B) GFP channel only. (B1) Phalloidin and GFP channels merged. (C) Quantification of the percentage of imaged segments/embryo that had EtOH-induced dystrophy. Embryos that constitutively overexpressed Paxillin-EGFP (n = 53e) had more segments with fiber detachments compared to AB embryos (n = 54e) after continuous treatment with 2% EtOH. (D) Quantification of percent of embryos with EtOH-induced fiber detachments. Fiber detachment frequency was significantly greater in embryos that constitutively overexpressed Paxillin-EGFP compared to AB embryos after continuous treatment with 2% EtOH. (E) Quantification of the proportion of imaged segments/embryo with dystrophy. sapje mutants that constitutively overexpressed Paxillin-EGFP (white bars) (n = 28e) showed no significant difference in the percent of segments that contained fiber detachments compared to those that did not constitutively overexpress Paxillin-EGFP (gray bars) (n = 23e) (p = 0.11). These data suggest that Paxillin overexpression does not reduce fiber detachments due to loss of sarcolemmal integrity. Scale bars are 50 micrometers. Error bars are standard error of the mean. * p < 0.05.