Improved cardiac contraction imaging in live Drosophila embryos

Drosophila melanogaster is a powerful model organism in which to address the genetics of cardiac patterning and heart development. This system allows the pairing of live imaging with the myriad available genetic and transgenic techniques to not only identify the genes that are critical for heart development, but to assess their impact on heart function in living organisms. There are several described methods to assess cardiac function in Drosophila. However, these approaches are restricted to imaging of mid- to late-instar larval and adult hearts. This technical hurdle therefore does not allow for the recording and analysis of cardiac function in embryos bearing strong mutations that do not hatch into larvae. Our technical innovation lies in transgenically labeling the cells of the Drosophila heart and using line scan-based confocal imaging to repeatedly image the walls of the heart. By plotting this line scan as a kymograph, heart contractions can be visualized and assayed, thereby allowing for quantification of physiological defects. This method can be used to obtain physiological data from known mutations that affect cardiac development yet are incapable of hatching into larvae for conventional analysis.•Use transgenic methods to label heart proper walls•Use high-speed line scanning to capture position of heart proper walls•Create X vs. time plot to visualize and quantify contractions over imaging period.