Characterization of cardiac looping in zebrafish

HERRERA, IDALIA; ARMESTO, RUBINA; BINOLFI, ANDRES; LOMBARDO, VERÓNICA A.

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Biofísica.; 2022

Cardiac looping is a highly conserved process among vertebrates that correctly positions the heart chambers relative to one another (1). Abnormalities in this process generate congenital heart defects in humans (2). Zebrafish (Danio rerio) is a vertebrate model organism with many applications for the study of heart morphogenesis and offers advantages over traditional mammalian models (3). The aim of the present work is to characterize the looping of the cardiac tube in zebrafish embryos. We described this process by imaging embryonic hearts during cardiac looping stages (24 - 57 hours post fertilization) using a fluorescent microscope in combination with a zebrafish reporter line [Tg(myl7:eGFP)twu34] (4), which expresses a green fluorescent protein (GFP) in the myocardium. We measured morphological variables, such as the size of the cardiac chambers, their relative positions, and their degree of overlap for the characterization of the heart looping. We also record the relative speed of blood flow, the onset of red-colored erythrocytes and heart beat rates. All these cardiovascular parameters play a relevant role in the normal development of the heart (5). Additionally, we analyzed phenotypic characteristics of the embryo to accurately establish their developmental stage. This research puts forward a detailed characterization of cardiac looping morphogenesis and the hemodynamic changes associated, which will serve as the basis for detecting and evaluating how abnormalities influence cardiac morphology and physiology, as well as discerning stages of critical changes during this process.Referencias:. (1) Lombardo et al., Development, 2019, 146, dev180091. (2) Ramsdell, Dev Biol, 2005, 288:1-20. (3) Brown et al., J. Cardiovasc. Dev. Dis., 2016, 3, 13. (4) Huang et al., Dev Dyn., 2003, 228(1), 30-40. (5) Dietrich et al., Dev Cell, 2014, 30:367-377.