The knowledge of those twists and turns ultimately could prove to be very important, Kao explained, because it helps paint a complete picture of an organism's evolution. With that picture intact, scientists stand to gain a better understanding of the way certain highly resistant infections develop and progress.
One such infection, Kao noted, occurs within the bodies of people with weakened immune systems. In such cases, a fungus that is normally kept in check increases to dangerous infectious levels, prompting doctors to prescribe antifungal treatments. Sometimes these treatments become ineffective, and Kao says that one of the reasons for that ineffectiveness is that the human body becomes a vessel for evolution, much like what occurred in her laboratory experiment.
"The fungus is being subjected to a selected pressure, in this instance drugs," Kao said. "As it fights for its survival, mutations occur that help make this fungus resistant to the drug treatments. Most of the clinical studies of these patients isolate just one sample of the mutation at one point in time. But a recent study that isolated these samples from different periods in time suggested that some of the later ones were not derived from earlier ones."
Understanding how this fungus evolves from its initial stages to its most recent stage could lead to the development of better treatments for it, Kao said.
The knowledge of an organism's complete "adaptive landscape" also is likely to benefit the rapidly growing field of metabolic engineering, Kao noted.
As scientists attempt to enhance cells so that they perform such beneficial activities as producing energy or disposing of waste, they'll need to know all of the particular pathways where genes are involved in the expression of a particular trai
|Contact: Katy Kao|
Texas A&M University