OEB graduate student Julius Tabin is a member of the Elya Lab. There he is investigating fungus-infected “zombie” flies and searching for the molecule or molecules that cause infected flies in their death throes to climb up to high vantage points (“summiting behavior”). He also recently published a paper in iScience looking into feline eye colors that began as a project for a comparative genomics course taught by OEB faculty Scott Edwards.
When he first arrived in OEB, Tabin was part of the Hoekstra Lab, where he looked into the genetics underpinning differences in burrowing behavior in two species of Peromyscus deer mice. However, once Hopi Hoekstra was promoted to Dean of FAS, Tabin needed to transfer to a new lab. Due to his interest in behavioral biology, the Elya lab was a natural choice. Tabin says that working in an MCB lab has been a lot of fun so far. He adds that he has been particularly excited about the breadth of techniques he has been able to experience, in part due to the Elya lab’s close ties with the neighboring Nett and Bellono Labs.
In the Elya Lab, Tabin is searching for molecules that cause summiting behavior. “Carolyn’s previous work implicated a juvenile hormone increase in the burst of activity that is characteristic of summiting flies,” says Tabin. “Although we know some relevant neurons that are necessary for this, we still have no idea what the fungus is doing or what compounds it is producing upstream to trigger this response in the fly. Figuring out the molecular basis of this behavioral manipulation would be very revealing.”
Identifying the molecules that induce summiting behavior is the first goal of Tabin’s graduate research, but success will open up more questions. “Once I find that molecule, the idea is how is it actually working?” Tabin says. “If the fungus is making the molecule, what is it binding to in the fly? Is it directly affecting the neurons? Is it affecting the muscle? Or if the fly is making a neuromodulatory molecule, how is the fungus causing the fly to make that? Right as the fly is doing this summiting behavior, the fungus is degrading the internal organs. Could degrading the internal organs be causing the production of some ‘summiting molecule’?”
Tabin recently carried out an analysis on a completely different biology topic–the evolution of eye color in wild cat species. He became curious about cat eye color while brainstorming potential final projects for Scott Edwards’s class on comparative genomics. Very little research has been done investigating the origins of eye color, but members of the felid family sport a diverse array of shades, including brown, blue, yellow, green, and gray. This variety stood out to Tabin, because close relatives of the cat family exclusively have dark brown eyes.
To gain insight into the evolutionary history of eye color in cats, Tabin and his colleague Katherine Chiasson of Johns Hopkins collected publicly available images of cats facing the camera head on. They then isolated the iris from each image and categorized those irises by color type. Once they had identified which eye colors occur in which species, Tabin used computational analysis to map the eye colors present in modern cats onto the felid family’s evolutionary tree and predict the eye colors of their ancestors. “We’ve reconstructed with probabilities the most likely eye color of each node. What’s most interesting to me is the ancestor of the felids…Our model predicts that the population of the ancestor of the felids had both brown-eyed individuals and the novel appearance of gray-eyed individuals,” Tabin explains. “And you can see that once you have gray eyes, the eye color diversity just blows up.”
Tabin and his colleague were also able to predict the ancestral eye colors quantitatively, allowing them to reconstruct the exact shades that ancient cats would have had. “I love this part of the paper because it means we are the first animals to see the color of these eyes since these felids were alive millions of years ago!” Tabin says.
The phylogenetic study can’t explain why novel eye colors evolved, but Tabin speculates that sexual selection may have played a role in ensuring their prevalence. He adds that he’d be curious to see what other studies are able to uncover about the evolution of eye color but that he has no plans to follow up at this time.
When he’s not working on biology research, Tabin contributes to Egyptology research. He is interested in the morphology of characters in the hieratic script, a cursive form of hieroglyphs used from 3000 BC until about 500 BC. His penchant for studying ancient lettering started in college when he took an introductory course in Ancient Egyptian to fulfill a language requirement as an undergraduate at the University of Chicago and became fascinated with the puzzle-like machinations of deciphering ancient languages.
Tabin continues researching Ancient Egyptian in his spare time. He is particularly interested in how hieratic characters changed over time. “My main project is using machine learning to do optical character recognition on hieratic, allowing us to compare hieratic in a digital and high-throughput way, in many ways borrowing techniques I learned from biology,” he says. Tabin has recently published a monograph and a conference paper on the subject.
For now, Tabin plans to continue his efforts to address interdisciplinary questions. He currently serves as OEB’s Graduate Outreach Coordinator, a position where he works with OEB Education and Outreach Manager Ogie Avramovska. One outreach project that Tabin is enthusiastic about is Emerging Scientists, a program organized by OEB that places high school students in Harvard labs for research projects. Emerging Scientists takes place during the school day and allows the high school students to earn course credit for participating in research, allowing students who cannot attend after school or weekend programs to access the research world. Avramovska and Tabin recently applied for and received a grant from the Harvard Culture Lab Innovation Fund, which will allow them to grow the Emerging Scientists program. Additionally, their upcoming “Evolution Day” event will include 20-minute introductions to Harvard labs and will be a recruitment tool for Emerging Scientists. Both OEB and MCB labs will host students through the program.
“Along with experience working in a variety of biological systems, Julius brings his infectious curiosity and enthusiasm to the lab,” says MCB faculty and Tabin’s advisor Carolyn Elya. “He is diving head-first into the zombie fly system and is taking full advantage of available expertise to approach his project using a breadth of approaches. I am beyond thrilled to have Julius as my first graduate student. I’m looking forward to every experiment yet to come.”
