3D Imaging and Visualization of Zebrafish and Giant Danio Hearts by Serial Block Face Scanning Electron Microscopy

Abstract

3D and 4D imaging of zebrafish heart can provide significant insights into the structural and dynamic nature of the development and growth of this important biomedical model. Transmission electron microcopy (TEM) and tomography allow high resolution ultrastructural imaging of subcellular structures, adding to our understanding of heart architecture in model organisms. Serial block face scanning electron microscopy (SBFSEM) is a novel approach to nanoscale volumetric imaging of tissues and cells. To test the usefulness of SBFSEM in investigations of structure‐function relationship in zebrafish and giant danio hearts, we acquired over 3000 serial block face scanning electron micrographs at 50 to 100 nm intervals, as well as transmission electron micrographs, of the hearts of these fish. We subsequently extracted anatomical and cellular structures of interest in larval and adult fish by semi‐automated segmentation, and generated 3D visualization of various heart regions. Our results show structural similarity in the integration of the compact and spongy hearts in these two species. Similar to the zebrafish, the adult giant danio possesses transitional cardiac myocytes and a network of cardiac fibroblasts in the junctional region. Ultrastructural analysis also reveals remodeling of the ventricular junctional space during repair and regeneration, as well as the presence of luminal lacunae and persistent intra‐myocardial space as late as 3 weeks post‐fertilization. Taken together, our studies demonstrate SBFSEM as a powerful approach to gather nanoscale volumetric structural data in developing, adult, and regenerating giant danio and zebrafish heartSupport or Funding InformationNIH R15 HD084262‐01This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.