Scientists reach roadblocks when they try to study diseases of the human heart merely because of its necessity for human life. In a new study from Florida State University, researchers turn to a giant flying water bug for answers.
, also known as the “water scorpion,” is native to South and Southeast Asia. It doesn’t have much in common with human physiology, except for the rhythmic movement of its flight muscles that resemble the beat of a human heart.
Because of its muscular similarities, Florida State scientists used L. indicus
to study how myosin and actin, the two filaments present in every muscle cell, interact to beat rhythmically. Inherited human mutations causing muscle diseases of the heart often stem from myosin rod mutations. While the researchers might not be able to study the myosin filaments of an actual human heart, they can learn about the same mechanisms where it’s present elsewhere in nature: via the flight mechanisms of L. indicus
"We study insect flight muscle because it is a simpler route to understanding human disease," said Florida State professor Kenneth Taylor. "Ultimately, we must understand human disease from either human filaments or at least mammalian filaments."
Taylor and his team produced a three-dimensional electron microscope image of a tiny filament of an essential muscle belonging to L. indicus
, which is made up of myosin and actin, just like the muscles of humans. The image is the first of its kind, showing the myosin filaments in a relaxed state, ready to re-extend.
The image taught the researchers how the molecular motors of myosin are ordered in a way to prevent contact with actin, which is responsible for re-extension of the muscle. "Many of these cardiomyopathy mutations may be understandable in terms of flawed muscle relaxation," Taylor said.
Next, Taylor and his team plan to work on enhancing the resolution of the electron microscope images in order to see “individual amino acids and accurately determine the key interactions between them.”
Taylor’s study was recently published in the journal Science Advances
Sources: Florida State University