"I really liked the people and the opportunity to be creative and collaborate on a black-box developmental project within microbiology."
Columbia graduate Hannah Dayton’s work on biofilms combines genetics and microbiology. A month after defending her thesis, she’s building on that work as a postdoc.
How did you become interested in science?
I grew up in New Bedford, Massachusetts, which is right on the water. There was this summer program called Sea Lab that I started in fourth grade where you spend all day learning about marine and aquatic environmental science. One of my favorite activities was the end-of-the-season trophy drive, where we would go to the ocean and find as many different organisms as we could and identify them by both their common name and their scientific name. I’ve always been a naturally curious person, but that program is what really got me interested in science.
Where did your career in biology research begin?
I started in Dr. Michelle Markstein’s lab my sophomore year of college at the University of Massachusetts, Amherst. I liked the research that she was doing on basic stem cell biology and cancer biology with fruit flies. I learned how to dissect the Drosophila gut, use the confocal microscope, and how to do all sorts of genetic crosses. I learned the power of genetics in that lab and the beauty of microscopy. From there, I went to Harvard Medical School as a research fellow for one year in Dr. Norbert Perrimon’s lab, and I continued doing work using Drosophila intestinal stem cells as a model.
What drew you to Columbia?
When I was interviewing at Columbia, I noticed how inviting the student community was. Everyone seemed genuinely excited to have students visiting and to show us around New York. There was just a different energy from the other interviews I went on. And at Columbia, the labs span many different research areas. I knew I loved genetics and microscopy but I'd actually done my undergrad in microbiology, and I always had this idea that maybe I'd be in a microbiology lab. I was drawn to Columbia’s biology program because it gave me the option to rotate in different types of labs and not be pigeonholed into one field.
You eventually landed in Dr. Lars Dietrich’s lab. What made that the best fit?
I really liked the people. It was a very inviting lab; everyone was so excited to help, and the lab meetings were engaging and fun to be in. And the project encompassed what I was looking for because it was a microbiology project—I worked on bacterial biofilms—but it was a developmental project within microbiology. Lars proposed that I work on this project that was kind of a black box: they saw this organization of cells within the biofilm and had no idea how it happened, why the cells were doing this, and what the purpose was. And I liked that because it's not your typical microbiology project; it encompassed development, genetics, and microscopy—things I had learned and loved during my time in Drosophila labs—and I was able to bring that to biofilms and microbiology and merge those two interests.
"It was a very inviting lab; everyone was so excited to help, and lab meetings were engaging and enjoyable to be a part of."
Could you talk a bit about your recent BioRxiv paper on this work?
We worked on the colony biofilm using Pseudomonas aeruginosa, which is an antibiotic-tolerant pathogen. In the lab, we were able to section the colony biofilm like a loaf of bread and look inside to see how cells are arranged. And what we saw was something intriguing: In the bottom of the biofilm, all these cells are completely disordered, but then, at a very specific point, they start to vertically align themselves one by one. Which is kind of crazy, because these are just little microbes. Why are they doing that? How? So we wanted to figure out the genetic and environmental factors leading to this.
I screened a bunch of different genes, and I found a few that were involved in this switch from disorder to order. We also found that environmental factors like nutrients and oxygen were also involved in how the cells arrange. But the big question is, why? We found that how these cells arrange themselves contributes to how different substrates move through the biofilm. And this could impact how antibiotics might move through biofilm. So if we're able to disrupt how the cells are arranging, we might be able to also change how something like an antibiotic might move through the biofilm. One of the major reasons why these things are antibiotic tolerant is because the antibiotics can't penetrate through the biofilm.
When you look back at your time at Columbia, what stands out?
I got the opportunity to work on this black box project that was very open, and I had the opportunity to be super creative with it. And part of the reason I was able to be so creative is because we were able to pull in all these different experts as collaborators, whether they were in our building, at Rockefeller Research Laboratories, or at other institutions in New York. This project wouldn't have been possible without all these different collaborators helping, and those collaborations might not have been possible had I been somewhere else where there weren't all these resources outside the lab’s door. I also met so many great people at Columbia, both in my lab and in my department. I was also able to go to a bunch of international conferences and share my science, which is awesome. I got to meet a lot of amazing people doing that. And outside of the lab, I led grad student recruitment for a few years: setting up what prospective students would do while they're here, making sure that they feel comfortable and learn as much as they can about our program, and show them what life could be like in New York. New York is great because you will never run out of new things to do. I had such a great experience during grad school. It was great scientifically, and I was able to experience so much being in New York City, going to Broadway shows, enjoying the excellent food, and meeting so many amazing people.
You defended your thesis last month, and you’ve just moved to Boston for a postdoc. What’s next?
I'm back at Harvard now starting a postdoc in Dr. Perrimon’s lab. I'm excited for that because I had done five years of Drosophila, and then I did my microbiology biofilm work, and what I'm going to do now is take those two interests and put them together. All the work that I've done with the biofilm has always been on an agar plate. We don't know what happens in vivo, whether there is bacterial cellular organization once you're in a live system. So we're going to take the Pseudomonas strains that impact cellular organization and look at them in the Drosophila gut to see if I see that same organization and, if so, whether substrate distribution is impacted when organization is disrupted, which could have implications for antibiotic susceptibly. I'm very excited to see where this project goes.