Scott Solomon
A forest of the fruiting bodies of the social amoeba Dictyostelium discoideum. An amoeba that must succeed at both single-celled and multicellular living to pass on its genes, "Dicty" allows scientists to ask questions about cooperation and cheating in multicellular organisms.
Biology researchers at Washington University in St. Louis are placing their bets on the wild side as they prepare a pack of social amoeba for competition Friday, May 16, in the first-ever Dicty World Race, an international science competition that carries a $5,000 prize for the single-celled organism deemed to be the “smartest and fastest” in negotiating a microscopic maze.
“We trust in nature’s ability to create the ultimate competitor,” writes the WUSTL team in a strategy statement posted on the competition's website. “Whether they are traversing the depths of soil to hunt the perfect morsel, or tracking a chemical signal through a synthetic maze, wild Dicty cells will crush the competition and prove that nature knows best.”
The WUSTL team is based in the lab of David Queller, PhD, and Joan Strassmann, PhD, both professors of biology in Arts & Sciences. Strassmann is the Charles Rebstock Professor of Biology and Queller is the Spencer T. Olin Professor of Biology.
Other WUSTL team members include biology graduate student Tracy Douglas and three postdoctoral researchers in the Queller-Strassmann lab: Debra Brock, Susanne DiSalvo and Suegene Noh.
The competition is the brainchild of Daniel Irimia, MD, PhD, a biological engineer and molecular machinist at Harvard Medical School. Irimia is building the microscopic maze through which the single-celled organisms must race to claim the top prize and “bragging rights” for labs submitting entries.
Expected to take one or two hours to complete, the
competition will be held in Boston beginning at 3 p.m. EDT Friday, May 16. The entire race will be live-streamed and blogged via the SciCast website and webcast in a frequently updated time-lapse video.
The
thoroughbreds in this steeplechase are known scientifically as Dictyostelium, or “Dicty” for short. They’ve been used for years as a
model organism for a variety of lab experiments, many focusing on
studies of cell mobility. Strassmann’s lab has isolated numerous strains
of wild Dicty that are genetically diverse and different from the domesticated
clones commonly used in labs around the world.
In early betting, WUSTL’s wild Dicty are odds-on favorites to win the competition, which is expected to include at least 20 teams.
Many of the teams have outlined their race strategies on a website dedicated to the experiment.
The race is designed to attract public attention to research on single-cell organisms and related issues of cell mobility in the human body, including important applications for the understanding of cell migration in wound healing, cancer and other diseases.
The race will pit various strains of Dicty and HL60 cells, both of which are models for studying human neutrophils, the white blood cells protecting us from infection. Neutrophils are often perturbed during disease and there are currently no known drugs capable of correcting their migrations.
According the competition website, the race will require cells to navigate a complex microfluidic maze to reach a pool of chemoattractant at the finish line. Engineered cell lines will be shipped from labs around the world and will attempt to complete the race course in the shortest amount of time and with the fewest mistakes (wrong turns). Diffusion of the chemoattractant will create a spatial gradient to guide cells along the shortest path to the finish line. The challenge is to engineer Dicty or HL60 cells to be both smart and fast.
While Dicty cells shine in precision, they lack speed, and while HL60 are good sprinters, they lack precision. Race organizers have invited laboratories around the world to send their fastest and smartest Dicty and HL60 cells. Cells will compete against each other and against human neutrophils. The maze used in the race is manufactured in the lab at the BioMEMS Resource Center and recorded using stereomicroscope cameras.
“What we're trying to do here is to have the people from the biology side and the people from the engineering side (together) so we can bring more tools to the race,” race organizer Irimia said. “This is a way of promoting science to the general public by saying that in science, we only know this much, and we need to learn more to make an impact on health. With the whole situation with science funding today, it's an important message to get out.”
Photo courtesy of Joan Strassmann
Research scientist Debra Brock collects soil samples that might contain wild D. discoideum clones at the biological field station in Mountain Lake, Va. It turns out that each pinch of soil hosts an ongoing psychodrama that pits farmers and their hired guns against crop thieves.