TY - JOUR A1 - Lombardo, Veronica A. A1 - Otten, Cecile A1 - Abdelilah-Seyfried, Salim T1 - Large-scale Zebrafish Embryonic Heart Dissection for Transcriptional Analysis JF - Journal of visualized experiments N2 - The zebrafish embryonic heart is composed of only a few hundred cells, representing only a small fraction of the entire embryo. Therefore, to prevent the cardiac transcriptome from being masked by the global embryonic transcriptome, it is necessary to collect sufficient numbers of hearts for further analyses. Furthermore, as zebrafish cardiac development proceeds rapidly, heart collection and RNA extraction methods need to be quick in order to ensure homogeneity of the samples. Here, we present a rapid manual dissection protocol for collecting functional/beating hearts from zebrafish embryos. This is an essential prerequisite for subsequent cardiac-specific RNA extraction to determine cardiac-specific gene expression levels by transcriptome analyses, such as quantitative real-time polymerase chain reaction (RT-qPCR). The method is based on differential adhesive properties of the zebrafish embryonic heart compared with other tissues; this allows for the rapid physical separation of cardiac from extracardiac tissue by a combination of fluidic shear force disruption, stepwise filtration and manual collection of transgenic fluorescently labeled hearts. KW - Developmental Biology KW - Issue 95 KW - zebrafish KW - embryo KW - heart KW - dissection KW - RNA KW - RT-qPCR Y1 - 2015 U6 - https://doi.org/10.3791/52087 SN - 1940-087X IS - 95 PB - JoVE CY - Cambridge ER - TY - JOUR A1 - Dietrich, Ann-Christin A1 - Lombardo, Veronica A. A1 - Abdelilah-Seyfried, Salim T1 - Blood flow and Bmp signaling control endocardial chamber morphogenesis JF - Developmental cell N2 - During heart development, the onset of heartbeat and blood flow coincides with a ballooning of the cardiac chambers. Here, we have used the zebrafish as a vertebrate model to characterize chamber ballooning morphogenesis of the endocardium, a specialized population of endothelial cells that line the interior of the heart. By combining functional manipulations, fate mapping studies, and high-resolution imaging, we show that endocardial growth occurs without an influx of external cells. Instead, endocardial cell proliferation is regulated, both by blood flow and by Bmp signaling, in a manner independent of vascular endothelial growth factor (VEGF) signaling. Similar to myocardial cells, endocardial cells obtain distinct chamber-specific and inner- versus outer-curvature-specific surface area sizes. We find that the hemodynamic-sensitive transcription factor Klf2a is involved in regulating endocardial cell morphology. These findings establish the endocardium as the flow-sensitive tissue in the heart with a key role in adapting chamber growth in response to the mechanical stimulus of blood flow. Y1 - 2014 U6 - https://doi.org/10.1016/j.devcel.2014.06.020 SN - 1534-5807 SN - 1878-1551 VL - 30 IS - 4 SP - 367 EP - 377 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Lombardo, Verónica A. A1 - Heise, Melina A1 - Moghtadaei, Motahareh A1 - Bornhorst, Dorothee A1 - Männer, Jörg A1 - Abdelilah-Seyfried, Salim T1 - Morphogenetic control of zebrafish cardiac looping by Bmp signaling JF - Development : Company of Biologists N2 - Cardiac looping is an essential and highly conserved morphogenetic process that places the different regions of the developing vertebrate heart tube into proximity of their final topographical positions. High-resolution 4D live imaging of mosaically labelled cardiomyocytes reveals distinct cardiomyocyte behaviors that contribute to the deformation of the entire heart tube. Cardiomyocytes acquire a conical cell shape, which is most pronounced at the superior wall of the atrioventricular canal and contributes to S-shaped bending. Torsional deformation close to the outflow tract contributes to a torque-like winding of the entire heart tube between its two poles. Anisotropic growth of cardiomyocytes based on their positions reinforces S-shaping of the heart. During cardiac looping, bone morphogenetic protein pathway signaling is strongest at the future superior wall of the atrioventricular canal. Upon pharmacological or genetic inhibition of bone morphogenetic protein signaling, myocardial cells at the superior wall of the atrioventricular canal maintain cuboidal cell shapes and S-shaped bending is impaired. This description of cellular rearrangements and cardiac looping regulation may also be relevant for understanding the etiology of human congenital heart defects. KW - BMP KW - Wnt KW - Cardiac looping KW - Hemodynamics KW - Zebrafish Y1 - 2019 U6 - https://doi.org/10.1242/dev.180091 SN - 0950-1991 SN - 1477-9129 VL - 146 IS - 22 PB - The Company of Biologists Ltd CY - Cambridge ER -