Frontal Cortex

The regeneration occurs by Marcos Sande, University of Bern by SNSF Scientific Image Competition Via Flickr: Entry in category 1. Object of study; Copyright: CC-BY-NC-ND: Marcos Sande FIRST PART The image represents a cardiomyocyte in a zebrafish heart during the regeneration process. The whole heart was cleared, whole-mount IF was done and scanned using a confocal zeiss 880 microscope with a 40x water immersion lense. Gray staining, MF20 (Alexa fluor 488),represents myosin heavy chain, cardiomyocytes can be seen. In red (Cy3), lineage tracing of sox10 cells, specific lineage of CMs during regeneration.These cells present a interest shape, atypical for a cardiomyocyte shape. The cardiomyocyte in red (sox10-derived cells) shows an expansion of the plasmatic membrane. These cardiomyocytes lead the regeneration process in the zebrafish heart. SECOND PART The zebrafish heart can repair the heart by themselves after injury. This cardiomyocytes, the cells of the heart, is one of the cells responsible to repair the damage. Using transgenic fish, we could follow specific cells to study this process using confocal microscopy.

Several dozen embryonic cardiomyocytes build the juvenile ventricular wall. a, Surface myocardium of half of a 30 dpf ventricular side, displaying clonal patches of varied shapes and sizes. b, c, Cardiomyocyte clones near the apex or chamber midpoint forming wedge/stripe shapes (arrowheads). d, Single-cell clone (green, arrowhead) positioned near a large clone (yellow, arrow). e, 30 dpf ventricular confocal slice, depicting a wall of single-cardiomyocyte thickness (Com) surrounding trabecular muscle (Tr). f, Percentage surface area (SA) occupied by 30 dpf clones (146 clones, 5 ventricles). g, Surface clones per ventricle (n = 10). Scale bars, 50 µm. Gupta V. & Poss K.D. Nature (2012) Clonally dominant cardiomyocytes direct heart morphogenesis