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Fig. 2
SHF progenitors do not add to the heart tube in Cyp26-deficient embryos.
(A–H) ISH of control and Cyp26-deficient Tg(nkx2.5:ZsYellow) embryos at 24 (A,E), 30 (B,F), 36 (C,G), and 48 (D,H) hpf. Nkx2.5:zsyellow (red) and myl7 (purple). (A–C,E–G) Brackets indicate nkx2.5:ZsYellow+ cells in the first nkx2.5+ pharyngeal arch. (F,G) Arrows indicate accumulation of nkx2.5+ cells adjacent to the arterial pole of the heart. (I,I’,K,K’) Tg(nkx2.5:Kaede) before and after photoconversion of the anterior lateral population of nkx2.5+ cells (bracket) in control and Cyp26-deficient embryos at 24 hpf. (J–J”,L–L”) Position of photoconverted cells (red, arrows) relative to the heart tube (green) in control and Cyp26-deficient embryos at 48 hpf. Images in I–J” and K–L”, respectively, are of the same control and Cyp26-deficient embryos. (M) Schematic depicting the three regions where photoconverted nkx2.5:Kaede+ cells contributed at 48 hpf. (N) Graph depicting percentage of contribution to the third and fourth PAAs, non-ventricular OFT, and ventricular cardiomyocytes (control-lateral n = 39, control-adjacent n = 8, Cyp26-deficient–lateral n = 52, Cyp26-deficient–adjacent n = 5). (O,P) Confocal images of arch arteries in Tg(nkx2.5:Kaede; kdrl:nlsEGFP) control and Cyp26-deficient embryos. (Q) Graph depicting quantification of the endothelial cell number in the third and fourth PAAs in control (n = 18) and Cyp26-deficient (n = 24) embryos. Ventral view, anterior up (A–H); dorsal view, anterior up (I,I’,K,K’); lateral view, anterior up (J,J’,J”,L,L’,L”); lateral view, anterior right (O,P). n > 20 per group for (A–H). Asterisk denote p < 0.05 by Chi Squared test. H, heart. Scale bar: 50 μm.