Last modified: Wednesday, January 18, 2006
‘Pilobolus’ a fungus cloaked in mystery
Michael Foos’ students learning to think like forensic scientists, identifying ‘evidence’ from Yellowstone
FOR IMMEDIATE RELEASE
Jan. 18, 2006
RICHMOND, Ind. -- Tracking fungi isn't always easy. They travel with animals, move through the air and have a wide range of shape and size variations that makes identifying the fungus difficult.
But research conducted at Yellowstone National Park by Michael Foos, professor of biology at Indiana University East, is beginning to show how one genus of fungus can be examined using a database that can one day lead to faster identification of fungi. This may be important especially for those fungi that spread disease among animals.
Foos began his work in Yellowstone in 1985. He was among the first scientists to begin working there after the formation of the Yellowstone Division of Research (now the Center for Resources) in the early 1980s. He selected Yellowstone because it met several criteria for his research. He looked for a large place with open spaces where he would be granted permission to conduct research. He also needed to be in a place where herbivores were roaming, but he didn't want to study fungus in relation to cattle and sheep.
Conducting his research in an Indiana park would be nearly impossible, Foos said. There are too many people in the parks, and they can trample the area he's studying. "I wanted a stable place," he said. "In Yellowstone, once you get away from the roads, the people don't go back so far, so usually you have a good study area without people walking all over it."
Another appealing aspect of Yellowstone is that it is so large that nearly every environmental condition exists, and he is able to study fungi in conditions that range from near desert to conifer forest.
Foos is studying the fungal genus Pilobolus. He said it is found growing in most areas worldwide, although it has mostly been reported in Europe and Asia. He identified the genus initially using morphological characteristics but has shifted to identifying the fungi using DNA sequences, which allow him to identify the isolates, or population, more easily.
He believes that Pilobolus would be reported more in North America if there was more economical importance attached to it. The fungi have been involved in transporting lung worms in Yellowstone's northern elk herd in an endemic infection; Pilobolus spread the worms, and the elk ate them and then contracted the disease.
While it is relatively easy to identify the genus and distinguish among the species of Pilobolus, the process of determining whether the isolates of a single species are genetic individuals or whether they come from a single strain is difficult. He is still in the middle of learning the techniques.
"The classification of this species is a horrible mess," he said. The characteristics of the fungus vary greatly depending on where it is growing -- one species can appear to be another. However, the DNA is stable over time, making it easier to determine if the isolates are of the same species.
Foos collects the samples and extracts the DNA from the fungus, assisted by two undergraduates. The samples are then sent to the Indiana Molecular Biology Institute at IU Bloomington where the DNA sequence analysis is performed. When the sequence analysis is complete, the code is posted on a Web site, and Foos downloads it to his computer at IU East.
Through his research, Foos said he hopes to develop a technique so that a single fungal sporangium can be collected from an animal, and that sample can be compared to samples in a database, allowing him to determine the species' location on a specific date.
"The value of this is if we can develop the technique with this fungus, we can do this with other organisms by taking a sample -- so small that you can hardly see it with the naked eye -- and identifying it in a database to determine what species it may be," he said.
This technique will help Foos determine if the same species of fungus is at a given location year after year, which is one question he'd like to answer. Since the fungi move with the animals, he said it is possible that the fungus found in one location may be different from the fungus found the next year. His question is whether there is a certain migration or flow of fungus from year to year and it is of ecological interest. If it is migrating, Foos said he would question whether the varieties are evenly spread over wide areas or are different in different areas. Do some grow better in wet or dry areas? Are they spread mainly by animals or are they spread evenly throughout the same area?
Not only is Foos' research providing answers to scientific questions, but it is also allowing IU East undergraduates to think like forensic scientists.
For several years, undergraduates have worked with Foos in the overall research project at Yellowstone, although none of them collected samples in the park. Different students have conducted taxonomy and physiology projects among other projects, to help Foos with his research.
"It has been a good project for undergrad students," Foos said. "The fungi are not pathogenic to students, so it makes it a good organism to work with for undergraduates. I think it has been a good experience for them."
Foos' students are now learning how to extract DNA using the same basic techniques that a forensic scientist would in the lab.
"They are learning techniques to obtain DNA from the organism, and if you can do that, you can learn to get DNA out of a person," Foos said.
Nickie Gray is a senior biology major. She said she has learned how to use a variety of equipment, how to extract DNA from fungi and how to do the extractions correctly.
"I get to see the process from beginning to end," Gray said. "I think DNA is interesting, and I like the actual hands-on work. I am not watching somebody or reading it. I learn more from doing it than actually reading about it. And this is an experience that not everybody gets. Not everybody gets the experience as an undergrad to do research work, so I actually feel privileged to do it."
Foos said he anticipates making more trips to Yellowstone. In October, he made a presentation at the Greater Yellowstone Public Lands conference summarizing why the park is a good place to conduct ecological research.
Yellowstone has been studied for more than 100 years, so there are numerous records of earlier research that a person can build upon, Foos said. One of the original researchers in Yellowstone was David Starr Jordan, IU's president from 1885-1891, who went to the park in 1889. Another IU president, John Merle Coulter (1891-1893), also conducted research there.
"We have two IU past presidents who did research in Yellowstone, and I used that as part of my argument that people have been out there doing research for so long, so it must be a good place to do research," Foos said.