Researchers wished to determine the effect of length on the mechanical efficiency of beating cilia. They concluded that most of the mechanical metrics such as force, power, and torque increased with the length of the cilia.
Researchers leading the study utilized video microscopy of high speed for analyzing a cilia model in order to determine the mechanical metrics.
“Something we did not expect is that the short cilia would not be periodic,” wrote Bottier. “The cilia are all moving, but we find no actual pattern of beating — nothing was synchronized — and that was our first discovery.”
For this purpose, the team utilized a green, single-cell alga, Chlamydomonas reinhardtii, which usually swims using 2 propulsive tails and is often used as a mammalian cilia model. Bottier, along with a senior undergraduate, Kyle Thomas made use of a mutant that had only 1 cillium. He then recorded its growth in a video. They then observed that the cilium required ninety minutes to get back to the original length, and although its waveform had varied slightly from the standard cilia, the key characteristics were still quite similar.
“We wanted to see the cilium beating, which we did with the video,” elaborated Bottier. “Then we asked how we could describe it, and the best way was to look at the average beat. We recorded five or six cycles of beating that repeat periodically, and from those five or six, we can reconstruct one average, which will remove the eventual outliers.”
“There are a lot of different models presented on what drives this bending pattern, so this study helped to learn which models are more accurate and which may have inaccuracies, so we can understand when there is a cilia dysfunction, what causes it because that could spark some conversations on how we go about treating it,” explained Thomas.