Twisting of the zebrafish heart tube during cardiac looping is a tbx5-dependent and tissue-intrinsic process.

ABSTRACT: Organ laterality refers to the left-right asymmetry in disposition and conformation of internal organs and is established during embryogenesis. The heart is the first organ to display visible left-right asymmetries through its left-sided positioning and rightward looping. Here, we present a new zebrafish loss-of-function allele for tbx5a, which displays defective rightward cardiac looping morphogenesis. By mapping individual cardiomyocyte behavior during cardiac looping, we establish that ventricular and atrial cardiomyocytes rearrange in distinct directions. As a consequence, the cardiac chambers twist around the atrioventricular canal resulting in torsion of the heart tube, which is compromised in tbx5a mutants. Pharmacological treatment and ex vivo culture establishes that

SUBMITTER: Tessadori F 

PROVIDER: S-EPMC8354640 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature