Professor Vincent Tropepe is the go-to scientist for all things related to neurogenesis. The Varsity got a chance to interview him and find out what it’s like to balance lectures, administrative duties, and a passion for research as a top-notch molecular biologist.
Dr. Tropepe’s current research interest in neurogenesis stems from his research experience as an undergraduate at McMaster. There, he worked in a lab that focused on structural brain differences between men and women and between people with different sexual orientations. Since this idea relied on a model based on brain development, it got him interested in the idea of neurogenesis, the process of producing neurons. After undergrad, he came to U of T as a graduate student and worked in a lab that studied neurogenesis and neuron stem cells. Now, as the sole operator of his lab, located in Ramsey Wright, his research continues in this vein but takes a broad view of this particular problem and studies it in different contexts. A majority of the projects in the lab focus primarily on using zebrafish, a tropical freshwater fish, as a model for research. His lab is currently investigating how neurogenesis works at the level of the gene. This research involves looking at genes that are usually transcription factors, meaning they participate in the transcribing of genetic information from DNA to RNA, but are involved in controlling gene expression. Among many other projects Dr. Tropepe has going on, he wants to know if the early developmental processes and mechanisms of neurogenesis are the same during adult neurogenesis. Are the stem cells in adult neurogenesis utilizing the same programs to make neurons as they did in the young embryo? To answer that question, his team needs to start from scratch and locate the process in the adult fish brain. “[Neurogenesis] is…very widespread throughout the [zebrafish] brain, much more so than in a mammal. We want to try to understand using zebrafish as a model: what is the neurogenesis that’s happening? Can we characterize it, and how does it work? An ultimate question would be why…do you need new neurons in your brain?” says Dr. Tropepe.
A very inquisitive scientist, Dr. Tropepe asks many questions, but perhaps the most burning question of all for him would be the case of neurogenesis in the retina. “I want to really understand how the stem cells in the eye make the decision to make a photoreceptor instead of something else. How does that actually work? That’s going to be absolutely critical if we’re going to understand stem cell biology in general but also if we’re ever going to be able to exploit this possibility of using stem cells to regenerate tissue. That needs to be solved, and so far, it’s not been solved.”
As a lecturer, the top two lessons Dr. Tropepe has learned in trying to be a better teacher is to make course material interesting and relevant. “I think that’s a big lesson that I’ve had to learn in trying to be a better teacher… Make [course material] very interesting for the audience so that they’re engaged, because if they’re engaged, they get it, they learn it, they understand it. I guess the second thing would be make it relevant, so in the courses that I teach, one of my philosophies is that it has to be, I’m not just going to teach you ‘these are the facts,’ I’m going to teach you why we think these are the facts. What is the actual evidence that allows us to draw this conclusion, that A affects B? That’s an important thing in science because there are really no facts in science — there are plenty of theories and models that are supported by a lot of evidence, and that’s about as good as we can get. So we have to be able to tell students ‘these are the important things that you need to know about molecular biology or about neurogenesis. These are the important concepts abut neurogenesis and here’s how we derive that information, but you are allowed to criticize that information — you’re allowed to criticize the way scientists have come to that conclusion because maybe they missed something, maybe they overlooked something, or maybe they’re over interpreting something.’ Now is the time to get students used to the idea [of thinking critically]. So I think those are the two things. Make it interesting and make it relevant.”
When asked on what advice he has to offer for prospective graduate students, Dr. Tropepe hits the nail on the head: “the mentors that I’ve had in my career have always had a common thread which is that they are deeply interested in the problem that they want to try to solve. They’re deeply interested in the science, in the research. For any prospective graduate student, you need that at that time in your life. You need to have a very deep desire to understand a particular field or to want to engage in a particular kind of research just because it is personally satisfying. That’s where it all stems from. From there, if you have that, you will be able to apply that research in many wonderful ways. Either being a great teacher or being someone that liaises with industry or being someone who can adapt that to a clinic, for medial application, whatever it is… But if you don’t have that deep desire for self- satisfaction, [for] just understanding, then I would say most people are not successful if that’s not the case. I think the successful people in science have that as their core.”
As for advice for undergraduates, Dr. Tropepe recommends working through examples and problems. “If you’re learning about how transcription factors might bind to a promoter to control transcription, look at some examples. What experiments do people use to show that this protein can stick to DNA, and after it’s stuck to DNA it will cause a gene to turn on? There are very clear experiments that one would do step-by-step to get to that conclusion. If you understand the way that works, then you understand the concept of transcriptional regulation to a great extent.”
Dr. Tropepe has three manuscripts still in the peer review process. A typical day in his lab is spent doing small portions from a smorgasbord of tasks. In addition to giving three to four hours of lecture a week, Dr. Tropepe has weekly meetings with members of his lab, reviews and critiques both manuscripts for publication in journals as well as grants, does all of the financing for his lab, and has a number of roles on committees within the department and university-wide. On his down time away from work and his family with two small children, he enjoys oil painting and jogging.