Fig. 6.

The NC and SHF contribute to distinct, non-overlapping lineages of the cardiovascular system. (A-X) RFP-labeled NC and GFP-labeled SHF were sequentially transplanted into the same unlabeled host Xenopus embryo at stage 17 and stage 25, respectively. The progeny of the labeled grafts were analyzed at different time points, in the whole embryo at stage 27 (A-H) and stage 35 (I-P) and on sections at stage 41 (Q-X). (A-D,I-L) Lateral views, anterior to right. (E-H,M-P) Ventral views, anterior to top. Sox8 expression at stage 41 is detected in the spiral septum (black arrow), a tissue derived from the GFP-labeled SHF (white arrows). GFP-labeled SHF also contributes to the wall of the outflow tract and to the proximal part of the ventricle. RFP-labeled NC-derived cells are detected in the aortic arch arteries (arrowheads) and in the NC-derived head mesenchyme. Red blood cells in the ventricle show non-specific autofluorescence (asterisks). U-X are higher magnification views of Q-T. Scale bars: 100 μm.