ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Stefan Choy is an author on ‘ Mutations in the albinism gene oca2 alter vision-dependent prey capture behavior in the Mexican tetra’, published in JEB. Stefan is a graduate student in the lab of Johanna Kowalko at Lehigh University, USA, investigating how molecular, genetic or neural changes impact behavior and behavioral evolution.
Stefan Choy
How did you become interested in biology?
While I have had intentions to pursue a career in academia since high school, I was originally more interested in chemistry and biochemistry. However, in college I had the opportunity to take a class on developmental biology and later a CRISPR gene editing lab with Dr Johanna Kowalko, my current advisor. In those classes I was introduced to the model organism Astyanax mexicanus, the blind Mexican cavefish, which I found a fascinating model for studying comparative evolution. Her approach to biological research inspired me to continue a research career in this field!
Describe your scientific journey and your current research focus
I first had the opportunity to intern at a research lab in high school, which changed my worldview on science. The tasks of designing my own experiments and solving problems that no one knew answers to fascinated me, and from that experience I knew that I wanted to become a researcher. In college I interned in a biochemistry research lab before working as lab technician with my current PI, Dr Kowalko, after graduating. I later switched over to being a graduate student in Dr Kowalko's lab, where I was able to continue working on my projects. Currently, my research focuses on using genetic mutants or surface/cave hybrids to study the genetic basis of behavioral differences between the surface and cave populations in A. mexicanus.
How would you explain the main findings of your paper to a member of the public?
One major question in the evolution of cave animals is whether many of the cave-adapted traits are caused by a few genetic changes or many changes. Previous work has identified the gene from this paper, oca2, impacting multiple cave traits, namely albinism and sleep. We were interested in whether oca2 impacts other cave traits, so we looked at how larvae feed. Surface fish and cave fish have different feeding behaviors, but the gene or genes causing this difference are not known. Using surface fish that have had their oca2 gene mutated, we observed that they feed in a cave-like manner, suggesting that oca2, in addition to causing albinism and reduced sleep, also impacts a third cave-adapted behavior! We also performed experiments where two fish competed for a limited number of prey, to see which fish was better at hunting. When raised in the dark, surface fish with the mutant oca2 gene captured more brine shrimp than fish without that mutation, suggesting that the cave-like feeding behavior provides a benefit for fish hunting in the dark.
A larval surface fish, moments before capturing prey. The eyes turn forwards for binocular vision and the body coils to strike.
A larval surface fish, moments before capturing prey. The eyes turn forwards for binocular vision and the body coils to strike.
What do you enjoy most about research, and why?
I enjoy the task of tackling questions that no one else has answered before. I don't think there are many fields where your objective is to, ‘find something out’. We generate hypotheses and make predictions on what the answer might be, but more often than not when testing those hypotheses and predictions we find out that things worked differently than how we expected. In science, ‘I don't know’ is a phrase that isn't bad, it's exciting because that means that we have something new to focus on!
What is your favourite animal, and why?
Flatfish! I was stunned to learn that when they're born, they are NOT flat! They look pretty much like a normal fish; they swim normally and have an eye on both sides of their head. However, as they age one of their eyes moves across the top of their head to the other side! Further, which eye rotates depends on the species. In some the left eye moves, in others the right eye moves, and in more still either eye can move! It's such a strange trait that reminds me of how wonderfully weird evolution can be!
What's next for you?
Now that I'm in my third year, I'm done with classes and can just chug away at research! I plan on continuing in academia after graduating as a post-doctoral fellow, but that is still a way off!
Stefan Choy's contact details: Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA.
E-mail: [email protected]
