Analysis of heart valve development in larval zebrafish

RT Martin, T Bartman - … dynamics: an official publication of the …, 2009 - Wiley Online Library
RT Martin, T Bartman
Developmental dynamics: an official publication of the American …, 2009Wiley Online Library
Malformations of the cardiac endocardial cushions (ECs) and valves are common congenital
dysmorphisms in newborn infants. Many regulators of EC development have been identified,
but the process of valve maturation is less well understood. Zebrafish have been used to
understand cardiogenesis through 6 days postfertilization, yet mature heart valves are not
present at this stage. By analyzing valve development in larval zebrafish, we identify that
valve development proceeds in two phases. Valve elongation occurs through 16 dpf …
Abstract
Malformations of the cardiac endocardial cushions (ECs) and valves are common congenital dysmorphisms in newborn infants. Many regulators of EC development have been identified, but the process of valve maturation is less well understood. Zebrafish have been used to understand cardiogenesis through 6 days postfertilization, yet mature heart valves are not present at this stage. By analyzing valve development in larval zebrafish, we identify that valve development proceeds in two phases. Valve elongation occurs through 16 dpf independently of localized cell division. Valve maturation then ensues, resulting from deposition of extracellular matrix and thickening of the valves. Whereas elongation is consistent between larvae, maturation varies based on larval size, suggesting that maturation occurs in response to mechanical forces. Taken together, our studies indicate that zebrafish valve morphogenesis occurs in the larval period, and that zebrafish may provide a unique opportunity to study epigenetic mechanisms leading to human congenital valvular disease, when studied at the appropriate developmental stages. Developmental Dynamics 238:1796–1802, 2009. © 2009 Wiley‐Liss, Inc.
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