This week, two scientists published a study presenting a new explanation for how and why sperm moves the way it does at the atomic level. There’s nothing surprising about scientists publishing an interesting discovery–the surprise is how they arrived at their conclusion.
The research, which was published in the journal ACS Nano, was led by Don Ingber–founding director of Harvard’s Wyss Institute–and Charles Reilly, PhD, a molecular biophysicist and professional animator who previously worked with filmmaker Peter Jackson. Their discovery stemmed from their quest to create an accurate scientific animation to educate the public, which they see as increasingly skeptical of science. They decided to create a visualization of how sperm swims that would be accurate at the micro, molecular, and atomic levels. The animation’s production process involved developing an physics-based model that followed current scientific data at all those scales.
The result is a fascinating working model of sperm down to the atomic level. It’s not just a visualization, but a true simulation (if you can ignore the gimmicky, completely unnecessary Star Wars envelope that doesn’t add anything to the narrative).
According to Reilly, “[a] lot of scientific investigations use a reductionist approach, focusing on one molecule or one biological system with higher and higher resolution without placing it in context, which makes it difficult to converge on a picture of the larger whole.” Their simulation had to work at every level, from the ground up. The previously observed behavior of molecules had to match existing data on the motion of the proteins, which also had to match the motion of the microtubes that move the central strand of the flagellum–the tail of the sperm cell.
It was an intensive task, according to Reilly, who says that they had to throw away their physics model because it wouldn’t match all of the existing data. But their work paid off–because it led to a new discovery that shows how the dynein hinge (the motor proteins that move along the microtubes) changes shape at the atomic level. This change, which is caused by the energy released by ATP hydrolysis (the reaction that transforms stored chemical energy into motion) is what “drives microtubule sliding and axoneme [the sperm’s flagelum] motion,” they write. The way the dyneins work together, Reilly points out, “is like rowers pulling together in a boat.” According to the authors, this would have been very difficult to see using conventional scientific simulations.
Igner and Reilly believe that more scientists should use their visualization approach: “We’ve demonstrated that art and science can benefit each other in a truly reciprocal way . . . art and science can get even closer to depicting reality in ways that anyone can appreciate and enjoy.”
This is not the first time science and art have worked together to visualize an unseen phenomenon, a process that some call “theoretical photorealism.” In Christopher Nolan’s 2014 movie Interstellar, a team of visual effects designers led by American theoretical physicist and Nobel laureate Kip Thorne used theoretical models and data to accurately render a black hole. Perhaps next time, Igner and Reilly can hire a good screenwriter to present their fascinating discovery with something maybe not as epic as Interstellar, but a bit more coherent than a Star Wars spoof.