ZFIN ID: ZDB-PUB-070303-27
Functional Modulation of Cardiac Form through Regionally Confined Cell Shape Changes
Auman, H.J., Coleman, H., Riley, H.E., Olale, F., Tsai, H.J., and Yelon, D.
Date: 2007
Source: PLoS Biology   5(3): e53 (Journal)
Registered Authors: Olale, Felix, Tsai, Huai-Jen, Yelon, Deborah
Keywords: Cardiac ventricles, Embryos, Blood flow, Heart, Zebrafish, Cardiac atria, Myosins, Cardiovascular physiology
MeSH Terms:
  • Animals
  • Cell Shape*
  • Heart/embryology*
  • Myocardium/cytology*
  • Zebrafish/embryology
PubMed: 17311471 Full text @ PLoS Biol.
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ABSTRACT
Developing organs acquire a specific three-dimensional form that ensures their normal function. Cardiac function, for example, depends upon properly shaped chambers that emerge from a primitive heart tube. The cellular mechanisms that control chamber shape are not yet understood. Here, we demonstrate that chamber morphology develops via changes in cell morphology, and we determine key regulatory influences on this process. Focusing on the development of the ventricular chamber in zebrafish, we show that cardiomyocyte cell shape changes underlie the formation of characteristic chamber curvatures. In particular, cardiomyocyte elongation occurs within a confined area that forms the ventricular outer curvature. Because cardiac contractility and blood flow begin before chambers emerge, cardiac function has the potential to influence chamber curvature formation. Employing zebrafish mutants with functional deficiencies, we find that blood flow and contractility independently regulate cell shape changes in the emerging ventricle. Reduction of circulation limits the extent of cardiomyocyte elongation; in contrast, disruption of sarcomere formation releases limitations on cardiomyocyte dimensions. Thus, the acquisition of normal cardiomyocyte morphology requires a balance between extrinsic and intrinsic physical forces. Together, these data establish regionally confined cell shape change as a cellular mechanism for chamber emergence and as a link in the relationship between form and function during organ morphogenesis.
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