Cardiac Valves
Project Title: Differentiation and function of intracardiac valve cells in the Drosophila heart
Funding Source: DFG PA517/13-1
Principle Investigator: Achim Paululat with Christian Meyer
The aorta and the heart chamber are physically separated by a single pair of specialised valve cells, which are integral part of the heart tube. The valve cells contain specifically oriented myofilaments that allow contraction upon heart beating. Highly characteristic for valve cells is the presence of giant membranous vesicles of endo-lysosomal origin. Differentiation of valve cells and, for instance, the genetic mechanisms that led to giant vesicles, is investigated by Christian Meyer in the lab.
The movie shows cardiac valves in action. They open and close the luminal space of the heart tube. Thereby the valves regulate systolic filling of the heart chamber and they control streaming directionality.

This is a double-staining for the valve cells (green) and all muscles (phalloidin staining, red). The valve separates the aorta with a narrow-lumen and the heart chamber with a wider lumen.
At higher magnification, individual myofibers within the heart cells can be seen