Hedgehog and Bmp signaling pathways play opposing roles during establishment of the cardiac inflow tract in zebrafish.

ABSTRACT: Cardiac pacemaking activity is controlled by specialized cardiomyocytes in the cardiac inflow tract (IFT), but the processes that determine IFT dimensions remain poorly understood. Here, we show that Hedgehog (Hh) signaling limits the number of IFT cardiomyocytes in the embryonic zebrafish heart. Inhibiting Hh signaling, either genetically or pharmacologically, results in an expanded IFT population. In contrast, reducing Bmp signaling decreases the number of IFT cardiomyocytes, while increasing Bmp signaling leads to an excess of IFT cardiomyocytes. Temporal inhibition of each pathway reveals that Hh and Bmp signaling act before myocardial differentiation to regulate IFT size. Simultaneous reduction of both Hh and Bmp signaling yields a relatively normal number of IFT cardiomyocytes, sugge

SUBMITTER: Robertson RA 

PROVIDER: S-EPMC12863301 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature