Chasing a Virus Through Mathematical Models
By Sam Chafe
Viruses mutate often and because their life spans are on the order of minutes or hours, a tremendous amount of change can occur in a short amount of time.
Viruses such as HIV and H1N1 have not always infected humans; at some point they mutated in a way that allowed them to attack a new host.
Paul Joyce, Holly Wichman and Craig Miller, all faculty in the College of Science, have set out to discover what the next move of the mutation process is going to be.
“We’re focused on understanding and predicting viral evolution,” says Miller, research assistant professor of biological sciences.
“Viruses can’t reproduce alone,” says Joyce. “They need cells to allow them to reproduce.”
The research begins in the laboratory, measuring how individual mutations affect the physical properties of the virus— things like how well the virus attaches to its cellular host and how quickly it reproduces inside the cell. They also collect data on how different environments alter the effects of mutations, and how mutations behave in combination.
These data are used in mathematical models, equations that use the genetic and physical attributes of the virus to predict adaptation.
One of the topics Joyce, Wichman and Miller are especially interested in is what allows a virus to switch from one host to another.
Currently, they are using a safe virus for testing. This virus attacks bacteria and not humans.
"We use a model system that was developed by Jim Bull at the University of Texas,” says Wichman, professor of biology. “I took a sabbatical and went there to learn about experimental evolution, and learned this model system.”
“We look at how the virus changed and then fit the changes to a mathematical model,” says Joyce. “Then, we test predictions of the model in the lab and if it’s wrong we make adjustments based on what went wrong.”
Each member of the group has their own area of expertise. Joyce makes the mathematical models that the group will apply to their theories of how a virus will mutate. Wichman works with the virus to study the mutations it makes while exposed to a different environment. And Miller acts as sort of a middle man.
“I keep my foot in two doors,” says Miller. “I know biology and math, so I am able to build mathematical models that are biologically meaningful.”
Miller helps take a biological system from Wichman and translate it into mathematical terms so that Joyce can push the mathematical portion even further.
So how did the three of them come together to work on this project?
“Paul and I have known each other for a while,” says Wichman. “We began working on this project when one of my graduate students did a rotation with him.”
A rotation is designed to provided practical experience in research questions and methods outside the major emphasis area of the student
This project was something that Joyce, Wichman and her graduate student, Darin Rokyta, would talk about, but it was Rokyta’s belief that something like this could really be done that got the project up and running.
Miller was a graduate student who had taken a class from Joyce.
“He would go to Paul’s office everyday and talk with Paul,” says Wichman. “We needed someone to be a bridge between the two worlds and he fits.”
Research like this is essential to the University of Idaho. As Idaho’s land-grant university, research like this helps reinforce its reputation of leading scientific discovery, and provides the opportunity for graduate and undergraduate student to conduct real research.
“Grants like this bring money into the university,” says Miller. “It helps employ people, as well as attract top-level faculty.”
Over the next four years, the three of them will use about $1 million in grant money to work on this project.