18. Hearts with a Glow
Michael Kotlikoff
Michael I. Kotlikoff, Biomedical Sciences, and research colleagues genetically engineered mice so their hearts glow with a green light with each heartbeat. This provides researchers with insight into how hearts develop in living mouse embryos, a better understanding of arrhythmias, and a potential means of observing cellular processes. The engineered mouse expresses a specially designed molecule that fluoresces when calcium, which increases dramatically with each muscle contraction, is released in heart cells. Calcium turns the sensor molecule off and on like a molecular switch, with greater fluorescence indicating higher calcium levels. Using a special high-speed camera, the researchers were able to track the embryo’s developing heart. The new technique was also able to plot the rise in calcium as the heart muscle contracted, showing the patterns, rate, and force of heart contractions.