Doctoral Student Studies the Effects of Micronutrient, Selenium
During her time at U-Idaho, Maia Benner, a PhD student in Bioinformatics and Computational Biology, has had the thrill of participating in two important discoveries in the lab of Professor Barrie Robison. The first occurred a few years ago, while she was employed in the lab as an undergraduate researcher/work-study student. At the time, Robison lab members were involved in a study focused on identifying an underlying genetic component for the behavioral changes that accompany domestication in animals. To do this, they were comparing gene expression in the brains of domesticated zebrafish and zebrafish caught from the wild in India.
From this study, one gene that was differentially expressed in the brain between wild and domesticated zebrafish caught the attention of the Robison lab. This gene was selenoprotein P. Pinpointing this gene as a possible candidate for the behavioral variability associated with domestication was a new discovery, and opened a new avenue of investigation for the lab as well as an opportunity for Benner to start her own project.
“It turns out that selenoprotein P primarily functions in transporting selenium throughout the body and in maintaining a local storage of selenium in the brain. Selenium is an essential micronutrient for proper health, which we obtain from foods such as meats, fish, grains, and certain nuts. Recently, selenium has been highlighted for its role in brain function and selenium deficiency is now associated with several neurodegenerative diseases like Alzheimer’s, Parkinson’s, schizophrenia, epilepsy, cognitive decline, and mood disorders such as hostility, depression, and anxiety,” Benner explained.
The Robison lab thought the behavioral aspects of selenium deficiency were interesting, and decided to perform some dietary manipulation studies to see how zebrafish would respond to increased levels of selenium in their diet. The assumption was that if they supplemented the diet with selenium, the wild fish, which showed anxious behavioral characteristics, would become calmer, while the domesticated fish, which demonstrate bold characteristics, would have little response to selenium supplementation.
The results of the dietary studies constituted the second discovery. They found that the response to selenium supplementation was not dependent on domestication status, but was actually dependent on the population of zebrafish. Four genetically distinct zebrafish populations were used in the dietary manipulation study, and the behavioral response to selenium was specific to population. Interestingly, the response to selenium varied between males and females as well.
“I looked further into [selenium supplementation] research in humans, and found that there have actually been quite a few studies looking at the effects of selenium on mood. Some of these studies showed a beneficial effect of selenium on mood in humans by reducing incidences of depression and anxiety, while others found no effect of selenium,” Benner said.
From her review of the selenium supplementation studies in humans, Benner found that the studies were carried out in extremely different human populations, from American males specifically to both males and females from different areas of Europe. For this reason, she began to think that the controversial results in humans might be due to genetic variation among study populations.
Investigators doing the human studies are now beginning to think that this is the case. They are finding genetic variants in the selenoprotein P gene as well as other genes involved in metabolizing selenium. The hope is that in the near future genetic information for individuals and human populations will become an essential factor when assessing responses to nutrients such as selenium.
There is recent evidence for specific genetic variants in human populations that influence their response to selenium. The Robison lab also thinks that genetic variation among populations is influencing the variable responses to selenium in zebrafish. Currently, they are looking for genetic variants in selenium metabolizing genes that are associated with the variable responses to selenium in zebrafish.
As a future direction for her career, Benner wants to continue pursuing nutritional genomics, the study of how genotype influences the way specific components of food are metabolized and how nutrients can influence the expression of genes. After her doctoral studies Benner plans to pursue a postdoctoral research position in bioinformatics and computational biology. Part of her, however, wants to leave the door open to her first love of marine biology or even employ her writing skills as an editor. In the near term, she hopes that her doctoral research will form the basis of a grant proposal to be submitted by the Robison lab to the National Institutes of Health.
In talking with visitors from other campuses, Benner has compared her graduate program experience with that of other students. She remarked, “I am extremely lucky to have the advisor that I do. It is hard to find an advisor that one, you simply click with, and two, that is so dedicated to your research and personal success as Dr. Robison is in mine.”
Not only has she had an outstanding major professor, but IBEST (Institute for Bioinformatics and Evolutionary Studies) has also afforded her exceptional opportunities through the financial support of her research. Also, collaborations within the Biological Sciences Department and Agricultural Sciences Department have been extremely helpful during her graduate career.
During the past three summers, Benner mentored Native American high school students from the HOIST (Helping Orient Indian Students and Teachers into STEM) program while they performed their own research projects within the Robison lab. She said that it was an interesting and challenging experience trying to explain scientific research to high school students, and yet very rewarding. Two students went on to pursue science in college and one of the students is currently working in the Robison lab at U-Idaho now as an undergraduate. Benner has also worked with several other U-Idaho undergrads in the lab.
“I like getting undergraduates involved in research because I was fortunate enough to be given the opportunity and it led me to where I am now.” she said.
In 2012, Benner was honored for her accomplishments by being named one of the recipients of the College of Science’s Nielsen Scholarship. She also received recognition in 2008 for the best oral presentation at the EVO-WIBO conference (conference for evolutionary biologists in the Pacific Northwest).
Benner has the research discussed here published in the journal Comparative Biochemistry and Physiology – Part A Molecular and Integrative Physiology, is co-author on an article looking at the effect of aging on male reproduction in zebrafish, is co-author for a book chapter on methods for behavioral measurements in zebrafish, and has a couple manuscripts in preparation.
For fun, Benner bikes a lot for mental relaxation. She also travels to visit family and friends in Washington state and Alaska.