Fig. 2

Fig. 2 Cardiac fusion requires the dimerization domain of Hand2.

a, Maximum intensity projections of confocal images of Tg(myl7:EGFP) expression in 20 hpf hand2 FLD^+/+ and hand2 FLD^−/− sibling embryos, as well as Tg(myl7:hand2-p2a-EGFP) expression in 20 hpf hand2 FLD^+/+ and hand2 FLD^−/− sibling embryos (of the 17 Tg(myl7:hand2-p2a-EGFP); hand2 FLD^−/− embryos, 9 displayed no rescue of myocardial migration and 8 displayed partial rescue). b, Maximum intensity projections of confocal images of Tg(myl7:mCherry-CAAX) expression in 48 hpf hand2 FLD^+/+ and hand2 FLD^−/− sibling embryos, as well as Tg(hand2 eh22:hand2-p2a-EGFP) expression in 48 hpf hand2 FLD^+/+ and hand2 FLD^−/− sibling embryos. c, Partial amino acid sequence alignment of Hand2, Hand2 EDE, Hand2 P and Hand2 AA. EDE: DNA-binding-deficient form of Hand2 (RRR to EDE); P: dimerization-deficient form of Hand2 (F to P); AA: phosphorylation-deficient form of Hand2 (TS to AA). d, In situ hybridization showing myl7 expression in 20 hpf hand2 FLD^+/+, hand2 FLD^−/− and Tg(hand2 eh22:hand2-p2a-EGFP); hand2 FLD^−/− sibling embryos. e, In situ hybridization showing myl7 expression in 20 hpf hand2 FLD^+/+, hand2 FLD^−/− and Tg(hand2 eh22:hand2 EDE-p2a-EGFP); hand2 FLD^−/− sibling embryos. f, In situ hybridization showing myl7 expression in 20 hpf hand2 FLD^+/+, hand2 FLD^−/− and Tg(hand2 eh22:hand2 P-p2a-EGFP); hand2 FLD^−/− sibling embryos (of the 16 Tg(hand2 eh22:hand2 P-p2a-EGFP); hand2 FLD^−/− embryos, 14 displayed no rescue of myocardial migration and 2 displayed WT hand2-like rescue). g, In situ hybridization showing myl7 expression in 20 hpf hand2 FLD^+/+, hand2 FLD^−/− and Tg(hand2 eh22:hand2 AA-p2a-EGFP); hand2 FLD^−/− sibling embryos (of the 15 Tg(hand2 eh22:hand2 AA-p2a-EGFP); hand2 FLD^−/− embryos, 9 displayed no rescue of myocardial migration and 6 displayed WT hand2-like rescue). All embryos are shown in dorsal views, anterior to the top. The proportion of embryos matching the image shown is indicated in the top right corner of each image. The scale bars apply to all images.