A research group at Tokyo Institute of Technology has found that Volvox, a multicellular green alga, changes the properties of flagella from the front end to the rear end of a spherical body, thereby efficiently responding to light such as phototaxis and phototaxis. I found that I was going to.
Volvox is an organism that swims in water using flagella, and when it senses light, it has a photo-amazing reaction (a reaction that stops swimming when suddenly exposed to strong light) and phototaxis (direction toward the light source or escape from the light source). (Reaction to swim toward) is shown.
Regarding these reactions, it has been found that when the Volvox is exposed to light, only the flagella of the anterior hemisphere reverse the direction of movement from normal swimming, but the regulator that causes the direction reversal is unknown. rice field.
Therefore, in this study, we conducted an experiment to confirm the effect of calcium ion, which is the first candidate for flagellar motility regulator.
First, the cell membrane of Volvox is lysed by treatment with a surfactant.Volvox dies, but when ATP, a bioenergy source, is added, the flagella start exercising again and begin to swim.Flagellar movement was observed under various calcium ion concentration conditions by this "zombie volvox method".
As a result, when ATP was added to the zombie volvox with a high calcium ion concentration, the flagella near the front end almost reversed the direction of movement.This clearly showed for the first time that the direction reversal of flagellar movement was due to calcium ions.It was also found that the angle of change in direction changed from 180 degrees to 0 degrees from the front end to the rear end of the body like a sphere.
Flagella also grow in various organs of the human body, and the results of this research are expected to contribute to the study of the human disease "primary immobile cilia syndrome" caused by abnormal flagellar movement.
