Shaping the zebrafish heart: from left-right axis specification to epithelial tissue morphogenesis.
Although vertebrates appear bilaterally symmetric on the outside, various internal organs, including the heart, are asymmetric with respect to their position and/or their orientation based on the left/right (L/R) axis. The L/R axis is determined during embryo development. Determination of the L/R axis is fundamentally different from the determination of the anterior-posterior or the dorsal-ventral axis. In all vertebrates a ciliated organ has been described that induces a left-sided gene expression program, which includes Nodal expression in the left lateral plate mesoderm. To have a better understanding of organ laterality it is important to understand how L/R patterning induces cellular responses during organogenesis. In this review, we discuss the current understanding of the mechanisms of L/R patterning during zebrafish development and focus on how this affects cardiac morphogenesis. Several recent studies have provided unprecedented insights into the intimate link between L/R signaling and the cellular responses that drive morphogenesis of this organ.
Hubrecht Institute and University Medical Centre Utrecht, 3584 CT, Utrecht, The Netherlands. j.bakkers@niob.knaw.nl
Jeroen
J
Bakkers
Manon C
MC
Verhoeven
Salim
S
Abdelilah-Seyfried
D000818:Animals; D019521:Body Patterning; D006321:Heart / Q000196:embryology*; D009024:Morphogenesis; D015027:Zebrafish / Q000196:embryology*