Regional patterns of BAV-associated gene expression do not differ between control and Alk2/Gata5-Cre mutant outflow tracts.
Sections transverse to distal (A–F), mid (G–L) and proximal (M–R) outflow tracts of control (A–C; G–I, M–O) and mutant (D–F; J–L; P–R) embryos showing expression patterns of Nos3 (Immunostaining: Nos3, pink; myocardium, blue-purple; nuclei, yellow; images color-inverted so that signal in single layer of endocardium is visible), (A, D, G, J, M, P); Gata5 (ISH: B, E, H, K, N, Q) and Notch1 (ISH: C, F, I, L, O, R). Staining for Nos3 and Notch1 present in virtually all endocardial cells in the OFT; Gata5 (e.g., arrow heads) detected above background in endocardium lateral to rather than over the two main cushions (septal, parietal: *) where Notch1 and Nos3 also more strongly expressed (arrows). Non-coronary leaflet develops from the intercalated cushion on the left in these images, right coronary from the adjacent part of the parietal cushion (* in the more anterior position). Gata5 also detected in second heart field (SHF) cells/most distal OFT wall. OFT, myo: outflow tract myocardium; OFT end, OFT endocardium; AV myo, atrioventricular myocardium; AVJ, atrioventricular cushion; RV, right ventricle; LV, left ventricle.