The science departments at Beloit College are not nationally renowned for cutting edge Ph.D. level research or state-of-the-art technologies. To be sure, they’re not minimalists either; the BIOL 291 course, for example,taught by Assistant Professor of Biology Micho Gravis, is designed for students to investigate relevant biological issues and pursue them independently in the laboratory. It’s a useful class for gaining hands-on experience in a research environment, and encouraging students to make substantial discoveries in the field of biology.
Two weeks ago, Kate Wolf’13 did just exactly that.
A Cellular, Molecular and Integrative Biology major and Physics minor, Wolf has successfully detected a protein from unicellular organisms known as choanoflagellates. Choanoflagellates are regarded as the single-celled organisms most closely related to animals, and they may provide insights about the evolutionary origins of multicellular animals from their single-celled ancestors. The protein that Wolf recently detected plays a key role in the growth of animal cells and has not previously been reported in choanoflagellates or other single-celled organisms.
Wolf can now confidently state that this discovery may be the “single most significant contribution I have ever made to humanity.”
Her journey to discovery began this past summer, working all day in the lab doing cancer research under the tutelage of Gravis. She was investigating the same protein that she recently discovered in choanoflagellates, a protein known in the scientific community to help cells survive in the face of cellular damage and stress. Wolf’s job involved analyzing the protein’s responsiveness in adverse cellular conditions.
At the beginning of this semester, Gravis decided to redirect Wolf’s research focus away from cancer; he inquired whether the same protein could be found in choanoflagellates. Gravis’ interest in the oddly shaped single cell organisms—“They look like sperm,” according to Wolf—stems from a research paper recently published by another group of scientists. The researchers failed to find the protein of interest in one species of choanoflagellates, and then extrapolated their findings to conclude that no species of the unicellular organisms would possess it. Gravis was unconvinced.
Gravis had good evidence to suspect otherwise. “He’s an expert [on the protein],” says Wolf. Gravis had analyzed the genome of a different species of choanoflagellates and decided that the organisms likely contained the protein. For biologists, the genome of an organism is its molecular blueprint. It holds the written instructions on how to assemble the particular proteins, cells and chemicals of an organism into a synergistic factory of life. Analyzing the genome allows scientists to predict the microscopic parts produced by particular organisms.
Having analyzed the genome of choanoflagellates, Gravis knew his species of choanoflagellates could assemble the protein of interest. Now he just had to prove it.
Wolf and Gravis embarked on a set of experiments to detect the protein of interest in a species of choanoflagellate that might express their protein. First, Wolf separated the protein by size from the thousands of other proteins produced by choanoflagellates. The next step was to obtain visible confirmation of the protein’s existence.
Wolf and Gravis utilized antibodies in the detection of their target protein. Antibodies can be used as highly selective probes to precisely detect one specific cellular protein out of thousands (or millions) of different competing proteins. Using an antibody that detected the target protein in cancer cells the previous summer, Wolf attached this antibody to the choanoflagellate protein sample and then another antibody on top of that which would generate color upon a chemical reaction.
After waiting for the chemical reaction to finish, Wolf returned to find a smidgen of color identifying the protein where she had expected it. She was the first person to have ever seen it.
Gravis and Wolf have done more than just discover a protein from an organism: they have taken a snapshot of evolution. All organisms with a nervous system produce Wolf’s discovered protein, and this protein is known to play an especially critical role in brain function in all animals.
With results indicating that some species of choanoflagellates do in fact produce this protein, Gravis and Wolf have demonstrated that this protein originated before the nervous system had yet evolved in animals, and indeed before even the simplest animals existed in the world. Gravis and Wolf documented a part of the methodical, evolutionary transformation of single-celled organisms like choanoflagellates into the first multicellular animals. Ultimately, their results may help scientists continue to piece together the evolutionary bridge separating unicellular and multicellular organisms.
Best of all, says Wolf, publishing this research may help contribute to Beloit’s scientific research program receiving the national credit it deserves.