Fig. 5

Fig. 5 Blood sinuses of the tunicate heart have conserved expression of genes found in the teleost BA and SV.

a Schematic summarizing the regions of the adult Ciona heart that were harvested for bulk RNA-seq. Pharyngeal blood sinus (PS), stomach blood sinus (SS), and cardiac tube (C). Mc – myocardial tissue (dark gray), Pc – pericardium (red), PcB – pericardial body. b Heatmap showing the expression of representative genes found in the C, PS, and SS of the adult Ciona heart. c Heatmap showing the expression of homologous genes to those in Ciona found in the V, A, BA, and SV of WT adult zebrafish hearts. d Summary depicting the adaptive response whereby the SV thickens due to proliferation from SMCs in nr2f1a^aco mutants. e Evolutionary model depicting the heart of the Ciona with bi-direction flow and the adaptive response in nr2f1a^aco mutants to regurgitation whereby the heart comes to resemble characteristics of the Ciona heart with equivalency in the sinuses at the arterial and venous poles.