Structural and Functional Characterization of the Adult Giant Danio Heart

Abstract

Cardiovascular diseases remain that number one cause of death in the northern hemisphere and are increasing globally in developing economies. In spite of evolutionary separation between fishes and mammalian, the use of non‐mammalian model species has significantly increased our understanding of cardiac diseases. We have recently described the growth and cardiovascular development of the Devario malabaricus, a giant danio (GD) species closely related to the zebrafish. We hypothesize that the adult GD heart can serve as a robust non‐mammalian model for in vivo studies of cardiac biology. Using immunostaining, transmission electron microscopy, scanning block‐face electron microscopy, and Doppler, we have characterized the anatomical and functional characteristics of the adult GD heart. First, we found that the adult giant danio possesses a thick and highly vascularized compact heart. Second, the GD heart possesses a junctional region populated with a fibroblasts network similar to that observed in zebrafish. Third, multiple large coronary vessels investing the compact myocardium are connected to and continuous with atrioventricular (AV) canal lumen. In addition, the AV canal and bulbus are highly innervated, suggesting complex regulation in heart function. Moreover, we demonstrate that their cardiac function can be measured using Doppler flow velocity. These studies along with previous findings support the GD as a robust model for the study of cardiac biology.Support or Funding Information1R15HD084262‐01, Buehler Family FoundationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.