Mysterious mortalities: A study of white nose syndrome and G. destructans from a molecular biology perspective

Overview

Since it was first identified in New York state bat populations in 2006, White Nose Syndrome (WNS) has caused the deaths of over 6 million North American bats. Found in bat colonies from Tennessee to Ontario, WNS has put several species at risk of extinction and has the potential to severely disrupt the ecosystems it affects.

Though it is now known that the syndrome is caused by the fungus Geomyces destructans, the scientific community had yet to definitively determine the cause of WNS at the time of this Plan’s writing. Contributing research to help solve the problem, this Plan compares the messenger RNA (mRNA) expression of healthy mammalian cells to those exposed to G. destructans to identify exactly how the fungus kills bat cells.

After culturing fungus off of live bats in Bat’s Den Cave in South Egermont, MA, G. destructans samples were grown in the Marlboro College laboratory and introduced to cultured mammalian cells. RNA samples taken from the cells exposed to G. destructans showed an innate immune response not present in the control group, indicating that the fungus actively attacks mammalian cells. This research strengthened the hypothesis that G. destructans was the cause of WNS.

Excerpts

“White Nose Syndrome has been difficult to study since researchers are not sure where the fungus came from, and why it is infecting bats. In fact, researchers have yet to confirm whether G. destructans is the cause of White Nose Syndrome, or if it is simply an opportunistic pathogen which grows once the bat’s immune system has already been compromised.”

“G. destructans is thought to kill bats by both damaging their wings, and by arousing them from hibernation more frequently. Frequent arousals can cause a loss in fat reserves, which in turn can cause altered immune response and, ultimately, death from starvation.”

“To determine gene expression, I extracted the total RNA from the cells and used microarray to analyze which genes had been up-regulated and which had been-down regulated. By looking at which sets of genes had changed, I could determine what biological pathways might be involved with the cell’s response to G. destructans.”

Reflections

“I was interested in molecular biology when I arrived at Marlboro, but I wasn’t sure if it was what I wanted to focus on. I also had a passion for caving, and I happened to start my plan work just as White Nose Syndrome started affecting bat populations in the Northeast. This provided a great opportunity to combine two subjects I was interested in.”