Broader Impact

Making Epistasis Fun

With some basic ingredients – including common yeast, a few test tubes, and notebooks – Dr. Maitreya Dunham’s broader impacts project has not only created research experiences for high school students – the work has also yielded new findings on specific interactions between genes (epistasis) that influence yeast resistance to azoles. Azoles are a class of synthetic anti-fungal compounds that inhibit the growth of yeasts and fungi, including those that affect foods and health.

The student-run experiments are a component of a collaborative project between Dunham and co-investigator Dr. Paul Rowley (“Collaborative Research: Eukaryotic virus-host interaction and evolution in Saccharomyces yeasts” (NSF award #1817816)). The students grow common yeast (S. cerevisiae) in a media containing an azole known to inhibit yeast growth. Successive generations of the most successful yeast are transferred to media with increasingly greater levels of azole. Students track the progression and return the final yeast cultures to Dr. Dunham’s lab for genetic sequencing. After the yeast’s genomes are sequenced, Dunham and her team return the results to the school and students research the mutations as part of their classwork.

The research enables students to observe how mutations in specific genes interact, and how correlated mutations lead to different changes in azole resistance. When the interactions are not additive, but are either greater or less than expected, it’s known as epistasis.

Pigmented yeast makes the research competitive and the experiments more visually exciting. In “yeast fights,” students observe the growth of differently colored yeasts to track which strains are more drug resistant. The colored yeasts come from the lab of Dr. Jef Boeke, also an MCB-funded researcher, and are developed by research assistants “playing” with yeast in their spare time. Some high school students call these colonies their “yeast babies” and, Dunham says, the students are excited to learn what genetic mutations are present in the final yeast colony.

The project itself has evolved, enabling the experiments to persist despite school closings caused by the COVID-19 pandemic. includes a step-by-step protocol and a form for requesting more information on how to participate.

Other collaborators include Dr. Ryan Skophammer, a biology teacher at Westridge School for Girls in Pasadena, CA, who initiated the idea by asking Dunham for a “real” science project for his class; Dr. Bryce Taylor, a yeast geneticist in Dunham’s lab who provides the genetic sequencing; and three undergraduate students. Rowley, the project’s co-investigator, runs yEvo labs in schools local to him in Idaho. “I feel like this is what a real scientist does,” wrote one student in response to a survey question. And indeed, it is just what real scientists do.


Broader Impacts are activities which advance societal goals through either the research itself or through complimentary efforts that advance the larger enterprise of science. Broader Impact activities don’t have to be original, one-of-a-kind ideas. However, they should clearly address a need, be well-planned and documented, and include both a thoughtful budget and a thorough assessment plan. Principle Investigator Allyson O’Donnell uses near-peer mentoring to pair high school students from under-represented minorities with undergraduates in the O’Donnell lab at the University of Pittsburgh, and assesses the outcomes to identify impact.

High school student Hanna Barsouk (Taylor Allderdice High School) and undergraduate student Ceara McAtee (University of Pittsburgh) work on a project in the O’Donnell Laboratory at the University of Pittsburgh.

Goals of the Broader Impact activity: “The near-peer program focuses on bringing underrepresented minority high school students into the lab and providing an opportunity for them to develop their passion for science. Undergraduates who serve as mentors have measurably stronger engagement with their work in the lab.”

Recruitment: “The high school students volunteer in the lab during the school year and then can apply to participate in more research-intensive activities during the summer. The summer internships are paid, and this is currently funded through an REU supplement as part of my CAREER award.” (NSF award 1902859)

How it works: “I pair the high school students with an undergraduate mentor so that there is a near-peer mentor connection with someone closer in age than a grad student or post doc. We have found that this gives the undergraduate a stronger sense of engagement and ownership in their research project. Plus, based on our assessments, this mentoring experience makes it more likely that the undergraduates will participate in outreach activities in the future. From the high school students’ perspectives, they have someone they are more comfortable asking questions of and who can help give them advice on navigating the application process for universities. Of course, this is in addition to having myself and other team members as mentors.”

How do you measure impact? “We have used the Grinnell College SURE survey [Survey of Undergraduate Research Experiences] and other reflective assessments of this approach and find that both the undergraduate and high school students report significantly enhanced learning experiences. Specifically, the high school students show higher learning gains in understanding the research process and how to think like a scientist, while the undergraduate students gain more knowledge about science literacy and confidence in their ability to engage the community in science.”

High school students Sara Liang (left) and Hannah Barsouk proudly display a box of plasmids they created to support their research project at the O’Donnell lab. The two attend Taylor Allderdice High School.

Future plans? “We first used this system of pairing high school students with undergraduate mentors while the O’Donnell lab was located at Duquesne University. We worked with eight students in 2017 and six students in 2018 and we expanded to other labs in the Department of Biological Sciences. We hope to expand the program here at the University of Pittsburgh as well, where it will also be supported by our fantastic outreach team.”



In April, the National Alliance for Broader Impacts (NABI) held its fifth annual Broader Impacts Summit at Skamania Lodge in Stevenson, WA. NABI is a network of more than 600 individuals working together to build institutional capacity, advance broader impacts, and demonstrate the societal benefits of research. NABI members come from educational institutions, museums, science centers, zoos, botanical gardens, professional societies, private industry, foundations, and other organizations. A list of member institutions is available on the NABI website and you can read about the objectives of NABI in a prior post on the MCB Blog. Established in part with funding provided by the Division of Molecular and Cellular Biosciences, NABI events and resources help researchers create and develop impactful broader impacts activities.

At the summit, Dr. Suzanne Iacono, Head of the Office of Integrative Activities (OIA) at the National Science Foundation, delivered a keynote address entitled Broader Impacts at NSF. She noted, across proposals, student education and broadening participation were two main focus areas. These areas were also a major point of discussion in several of the sessions at the meeting.

The theme of the three-day summit was the “Power of Partnerships.” Sessions focused on three strands: innovative BI approaches and activities, faculty and student development and training, and broader impacts infrastructure, skills, and tools. Research into the role of partnerships in empowering high-quality outreach, models for public engagement partnerships, and best practices in the assessment and evaluation of broader impacts were presented, which created a foundation for data-driven conversations about broader impacts for the 21st century and beyond.  Presenters discussed how to construct strong science education and build outreach partnerships with a diverse array of partners such as citizen scientists, startup companies, museums, community partners, STEM graduate students, engineers, and faculty. Summit participants also learned how to use crowdfunding, cinema, social media, and Twitter as tools to facilitate outreach.  Discussion also focused on how to reach non-traditional public audiences, minorities underrepresented in STEM fields, and the next generation of scientists. Panelists offered lessons learned while establishing outreach partnerships such as University of Wisconsin – Madison Science Alliance, which connect scientists with K-12 educators, parents, lifelong learners, students, and others. The Summit had a strong focus on the future of BI and NABI.  Sessions engaged member feedback, discussed the creation of a peer-reviewed journal about broader impacts, and considered the role of the NSF CAREER Program in integrating intellectual merit and broader impacts. Slides for each presentation are available at

If you are interested in becoming a member of the National Alliance for Broader Impacts network, visit their website at to join for free. Registration for the next summit, which will be held at the Providence Biltmore April 25-27, 2018 will become available on the NABI website at

This work is partially funded by the Division of Molecular and Cellular Biosciences, Award #MCB – 1408736.