Fig. 8

NCCs and autonomic nerve markers in the right-sided SAN in mice and humans at mid-cardiogenesis. A–D Mouse sections of the right-sided SAN (blue/white dotted line) at E13.5. A’–D’ Human sections of the right-sided SAN (black/white dotted line) at 8WGA. A, A’ In both species, neural crest(-derived) cells (Wnt1Cre-GFP⁺ in mice and HNK-1⁺ in humans) are present at the right-sided SAN (red arrows). B, B’ In both species, TUBB3⁺ nerves are found in the SAN (red arrows and arrowheads). C-D, C’-D’ In mice, both parasympathetic [TUBB3⁺/ChAT⁺, red arrows in (B) and (C)] and sympathetic [TUBB3⁺/TH⁺, red arrowheads in (B) and (D)] nerves are present. Also note the ICA cells [TUBB3⁻/TH⁺, yellow arrowheads in (D)]. In human, the nerves remain undifferentiated [(red arrows in (B’)], evidenced by the negative staining for ChAT (C’) and TH (D’). Scalebars: 50 μm. RA: right atrium; RCV: right cardinal vein