Jerry Gollub and University of Cambridge collaborators discover a new mechanism for the swimming of micro-organisms.
Physics Professor Jerry Gollub is an author of a paper in the July 24 issue of Science. The article concerns research performed by a team from University of Cambridge (which includes Gollub, Marco Polin, Idan Tuval, Knut Drescher, and Raymond Goldstein), where Gollub was recently Leverhulme Visiting Professor.
The research focuses on the swimming of single algae cells only 10 micrometers across. These and other algae cells produce a significant fraction of the earth's oxygen. Their swimming involves the synchronized beating of long appendages known as flagella or cilia, which are also important for many other types of cells, such as those lining the interior of the lung.
The Cambridge research team showed that the coordination of the algae cells' two flagella is possible because of forces transmitted between them through the intervening fluid. In a“Perspective” article written about this work, which also appears in the July 24 issue of Science, two experts comment that the coordinated motion of flagella allows the cells to enhance their nutrition and may have contributed to the evolution of multi-cellular organisms.
However, about five percent of the time, the cells choose to make their flagella beat at different rates, causing them to turn sharply. Why would the cells do this? One possibility is that they need to avoid contact with predators. According to Gollub,“The biochemical means by which the organism makes this choice, and the role of chance in the process, are not yet understood.”
In related work submitted to a different journal (Physical Review Letters), Gollub and collaborators from Cambridge (Kyriacos Leptos and Raymond Goldstein) and Haverford (Postdoctoral Research Associate Jeff Guasto) have studied the stirring of the fluid by the swimming algae cells, which also affects their nutrition.
Gollub went to Cambridge for his sabbatical leave in order to extend his prize-winning research on fluid motion to situations involving living organisms.“I was fortunate to be able to work with a superb team, including a number of talented students and postdocs,” he says.“My own contributions were quite modest.”
