Kirsty WanOct 15
Final version of our paper on ciliary metachronal waves out now in Science Advances! doi.org/10.1126/scia... This is the main thesis work of my PhD student Rebecca Poon, who caught many #platnereis larvae and tirelessly ablated them with a laser. THREAD
Show threadKirsty WanOct 15
What is a #Platynereis you might ask? I would never have encountered them were it not for @jekely.biologists.social.ap.brid.gy The adult worm is extremely ugly, in contrast, the larvae, is adorned with many cilia, which naturally makes them beautiful. The 2-day old larva is approximately spherical
Show threadKirsty WanOct 15
with a single equatorial band made up of many many cilia. These propagate so-called 'metachronal waves', always in the same direction! The wave may look continuous, but in fact it's not!
Show threadKirsty WanOct 15
look at the discontinuities in the following kymograph (space-time plot of beat phase), turns out these come from the natural gaps between neighbouring multiciliated cells (each with several hundred cilia!).
Show threadKirsty WanOct 15
to test if spatial gaps could break wave transmission, we (Rebecca) started removing more and more cilia from this equatorial ring, finding that spatial continuity of the cilia within a single multiciliated cell is both necessary and sufficient for wave continuity
Show threadKirsty Wan
in fact, you can just keep removing cilia, until all but a single wavelength of the ciliary band remains. The tiny patch keeps propagating a metachronal wave! [watch video till the end] (see paper for other interesting details about these waves)
Oct 15 at 8:53pmWeb
Show threadKirsty WanOct 15
#platynereis is an excellent model for cilia dynamics and coordination, incl. how metachronal waves emerge - during a process known as ciliary closure. These events are neuronal controlled, allowing the larvae to finely control their position in the water column elifesciences.org/articles/26000
Show threadKirsty WanOct 15
Our findings highlight a remarkably modular and robust propulsion mechanism found in a marine larva, which relies on short-range physical interactions to achieve ciliary coordination. Thanks to Rebecca for all the hard work and @jekely.biologists.social.ap.brid.gy for the collaboration!