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Fig. 7
Rescue of defective convergent extension in lbx1b-overexpressing embryos by wnt5b and RhoA mRNA injection.
(A) Dorsal view of dlx3b/hgg1/ntl expression in tail bud embryos injected with buffer (ctrl), lbx1b mRNA (lbx1b), lbx1b plus zebrafish wnt5b mRNA (lbx1b+wnt5b), or lbx1b plus human RhoA mRNA (lbx1b+RhoA). (B) Quantitative analysis of convergent extension movement in the tail bud embryos in (A). (ctrl, n = 26 and 29; lbx1b, n = 27 and 33; lbx1b+wnt5b, n = 27; lbx1b+RhoA, n = 32). The extent of defective convergent extension was evaluated by measuring the distance between the inner edges of bilateral dlx3b expression at 3 regions as indicated by the arrows in panel A. Wnt5b or RhoA mRNA injection significantly rescued defective convergent extension (*p < 0.01). (C) Dorsal view of 48 hpf Tg(hsp:Gal-VP;EGFP:UAS:lbx1b) embryos upon heat shock at 4 hpf with buffer (lbx1b), wnt5b mRNA (lbx1b+wnt5b), or RhoA mRNA (lbx1b+RhoA) injection. (D) Quantitative analysis of body curvature in Tg(hsp:Gal4-VP;EGFP:UAS:lbx1b) embryos upon heat shock at 4 hpf with buffer injection (lbx1b, n = 16 and 21; lbx1b+wnt5b, n = 18; lbx1b+RhoA, n = 18).The severity of body curvature was significantly alleviated in Wnt5b or RhoA mRNA-injected embryos with heat shock at 4 hpf, *p < 0.01. Severity of body curvature was quantified by the angle as described in Fig 3. F2 lines of driver transgenic and responder transgenic fish were used. Injections were performed at doses of 50 pg/embryo for lbx1b mRNA, 40 pg/embryo for wnt5b mRNA, and 15 pg/embryo for RhoA mRNA.