Fig. 8

Laminin expression is significantly reduced in AG1478-treated embryos and Laminin α2 overexpression within SCs restores normal Mbp expression in csp−/− embryos. (A-B″) Laminin immunostaining in foxd3:gfp (A-A″) and foxd3:gfp embryos treated with AG1478 (B-B″) at 48 hpf. Arrows indicate GFP+ SCs in A and laminin expression along the PLLn in A′. Scale bars: 20 μm. A″ and B″ are the merge images of A and A′ and of B and B′, respectively. (C) Quantification of laminin fluorescence intensity along the PLLn in foxd3:gfp (average of 33.63±1.52, n=6 embryos) and foxd3:gfp/AG1478-treated (average of 21.67±1.44, n=8 embryos) embryos (**P=0.0013), a.u., arbitrary unit. (D,E) Lateral views of EGFP expression in SCs of the PLLn following pUAS-lama2 injection in sox10:Gal4VP16 embryos. Scale bars: 20 μm. (D′,E′) Lateral views of mCherry-tagged secreted laminin in SCs and within the PLLn. (D″,E″) Merge of D and D′ and of E and E′, respectively. mCherry-tagged secreted laminin is highlighted in E‴ at higher magnification; white arrows in D″ and E‴ indicate extracellular laminin within the PLLn and white arrowheads in E″ and E‴ indicate mCherry-tagged laminin within SCs. (F) Lateral view of Mbp immunolabeling in control embryo at 3 dpf. Scale bar: 50 μm. (G,G′) Lateral view showing the absence of EGFP expression in SCs of the PLLn (G) that correlates with a significant decrease in Mbp immunolabeling (G′) following pUAS-lama2 injection but with no EGFP/mCherry expression in csp−/−/sox10:Gal4VP16 embryos. n=24. Scale bar: 50 μm. (G″) Merge of G and G′. (H,H′) Lateral view showing EGFP expression in SCs of the PLLn that correlates with normal Mbp immunolabeling (H′) following pUAS-lama2 injection with positive clones of EGFP/mCherry in csp−/−/sox10:Gal4VP16 embryos. n=8. Scale bar: 20 μm. (H″) Merge of H and H′.