Fig. 8. At stage 11, the inflow tract shows continuity with the primary heart
fields. (A) HNK-1 expression in the myocardium and dorsal mesocardium at the
cardiac inflow tract. (B) Nkx-2.5 expression overlaps that of HNK-1 but
extends slightly farther into the splanchnic mesoderm of the primary heart
field. (C) Myocardial differentiation as indicated by MF-20-positive staining
(red) in a stage 11 quail embryo double stained for QH-1 to show the
endothelium/endocardium (green). (D) Gata-4 expression appears to replicate
that of Nkx-2.5. (E) BMP-4 is not expressed in or near the cardiac inflow
myocardium. (F) FGF-8 is expressed at very low levels by the ectoderm lateral
to the pharynx, but is not seen in or near the cardiac inflow myocardium. All
scale bars are 100 µm. Magnification in C is similar to that in B.
