(A–L) Left lateral views of indicated TGF-β pathway component expression in 28 hr post-fertilization (hpf) embryos. (A–D) Transcripts encoding the canonical TGF-β receptor paralogs RIa/b and RIIa/b are broadly distributed in the pharyngeal region. (E–G, I, and J) Expression of the indicated TGF-β ligands in the pharynx. (H, K, and L) Double in situ hybridization highlighting overlap of indicated TGF-β pathway component transcripts with transcripts encoding the pharyngeal endodermal pouch marker, nkx2.3. (n = 30–40 embryos per in situ hybridization probe). Scale bars, 200 μm.