Postdoctoral researcher Andrea Hodgins-Davis was awarded a Ruth L. Kirschstein National Research Service Award from the National Institutes of Health, Department of Health and Human Services, for her project, “Environmentspecific effects of new mutations on gene expression.” The three-year award runs through 2018. Hodgins-Davis works in the lab of Professor Patricia Wittkopp.
“I work on budding yeast (Saccharomyces cerevisiae), the same happy microbe that brings us bread and wine,” Hodgins-Davis said.
“We're trying to understand how changing the yeast's DNA alters the traits it embodies in the world. In this case, the trait we are looking at is the extent to which the expression of a gene is dialed up or down, which should translate into more or less of the protein this gene codes for. So, some changes to the DNA (aka mutations!) result in greater gene expression and some mutations result in less gene expression.
“Interestingly, mutating DNA is not the only way to change gene expression levels: changing the environmental context that a yeast cell experiences can also cause differences in expression levels. In our case, we feed our yeast different sugars and then compare the gene expression of genetically identical cells grown in media containing the sugar glucose, for example, to those of cells grown in media containing galactose, ethanol or glycerol. Sometimes they differ and sometimes don't.
“The really big question then is what happens when you combine these two different axes of variation: the changes in gene expression that come from mutations in the DNA and the changes in gene expression that occur when a population of yeast (or bacteria or fruit flies or Daphnia or people!) experience a range of different environments. If we take into account the possibility that the effects of new mutations can depend on the environment in which a yeast cell is living, can we get a fuller picture of the spectrum of gene expression variation that makes up raw material for evolution? As evolutionary biologists, we're really always in the business of trying to understand where variation comes from and what happens to it in the course of evolution.”
The developing research is important for issues including cancer metastasis and the ability of pathogens to jump into new species.
Jennifer Lachowiec, an EEB postdoctoral researcher, was awarded a Ruth L. Kirschstein National Research Service Award from the NIH HHS for her project, “Uncovering origins of convergent enhancer activities.”
“Sees, seize, and seas – these three words all sound the same, but are spelled in different ways because of flexibility in spelling rules,” said Lachowiec. “Just like the letters in the English language, the bases A, T, G and C that make up DNA can be arranged differently to produce the same outcome (or, "sound") in an organism.
“In my project, I am searching for the ‘spelling rules’ or cellular mechanisms that allow for flexibility in DNA sequences. To discover these rules, I am using the trait of pigmentation in fruit flies. Different species of fruit flies exhibit a range of pigmentation traits, with some species looking nearly identical to one another. In two species with identical pigmentation, there are no DNA similarities in the sequences that regulate where, when, and how much a pigmentation gene is produced. What cellular mechanisms allow for this extreme flexibility? This same type of flexibility in DNA sequences observed in pigmentation genes also allow for cancer cell DNA to accumulate massive loads of mutations and still survive. If the mechanisms that allow for flexible DNA sequences are identified, we may be able to block these mechanisms to force cancer cells to succumb to their own mutations.”
The two-year award begins September 1, 2016. Lachowiec works in the Wittkopp Lab.
Nina Wale, an EEB postdoctoral researcher, won the W.D. Hamilton Award for Outstanding Student Presentation from the Society for the Study of Evolution at the June 2016 Evolution meeting in Austin, Texas. Her talk title was “Drug treatment without the evolution of drug resistance.”
Wale’s talk was based on research performed as a graduate student at Penn State in Dr. Andrew Read's lab. Currently, she works in the lab of Professor Meg Duffy.
Using the rodent malaria parasite Plasmodium chabaudi, Wale demonstrated that modifying the availability of nutrients in the within-host environment can weaken drug resistant parasites, making them unable to compete with drug susceptible parasites. As a result, drugs can be used to cure the host of malaria without drug resistant parasites emerging afterward.
Though the work is not yet published, a writer at Science News summarized the exciting research in “Letting parasites fight could help battle drug resistance, too.” As winner, Wale received $1,000 and a one year membership to the SSE. This prestigious award is named after the late Bill Hamilton, a University of Michigan professor of evolutionary biology from 1978 - 1984.