New biosensor illuminates physiological signals in living animals

Credit: Howard Hughes Medical Institute

Eric Schreiter and Luke Lavis thought they had figured it out. In 2021, the Janelia group leaders reported that they had developed a way to combine Schreiter’s engineered protein biosensors and Lavis’s bright, fluorescent Janelia Fluor dyes.

These sensors, which could track different physiological signals and brightly illuminate them in far-red light, would in theory enable scientists to perform imaging in live animals and track multiple physiological signals at the same time—two aspects of biological imaging that were difficult to do with existing sensors. Far-red light can penetrate deeper into tissues than other wavelengths, and it gives scientists an additional color to use outside the typical hues, like green and red, used in biological imaging.

“Everything was great, and it was fantastic, and we were happy—until we tried to use the sensors in animals, and it pretty much totally failed,” Schreiter recalls. “It was a bit of a bummer.”

Luckily, Helen Farrants had just arrived at Janelia for her postdoc in Schreiter’s lab, and she accepted the challenge of re-developing the protein biosensors to carry out their original intention.

Starting from scratch, Farrants created a new way for the engineered protein biosensors and the JF dyes to work together, enabling the team to accomplish their goal of measuring physiological signals in live animals. Their first proof-of-principle sensor, dubbed WHaloCaMP, can detect calcium signals—a key part of cellular communication—in live fruit flies, zebrafish, and mice.

 

 

 

 

By Howard Hughes Medical Institute

Article can be accessed on: phys.org