Decoding the rules that shape cell identity

Dr. Selin Jessa is joining LTRI as an investigator and an assistant professor of molecular genetics at U of T’s Temerty Faculty of Medicine.

Using genomics and machine learning, she aims to answer one of biology’s most fundamental questions: how does the same genetic blueprint give rise to many different cell types that make up the human body? 

Although every cell contains nearly identical DNA, each switches on a different complement of genes to be able to perform its specialized role. Dr. Jessa’s research aims to uncover the rules behind gene regulation and understand how they shape cell identity during development, and how they become disrupted in disease. Once deciphered, this regulatory code may be programmed for gene and cell therapy and that is the ultimate goal is Dr. Jessa’s research.

“If we can understand the rules of gene regulation, we could potentially program them,” she says. “We could target specific genetic variants and edit them for gene therapies. We could design cells to achieve specific functions,” she said.

Dr. Jessa became fascinated by computational biology while completing a joint program in computer science and biology at McGill University. During her PhD with Dr. Claudia Kleinman at the Lady Davis Institute, she used computational approaches to investigate the developmental origins of childhood brain tumors, identifying cell populations that may be particularly vulnerable to cancer-driving alterations.

The work sparked a broader interest in how cell identity is established during development and disrupted in disease. During postdoctoral training with Drs. Anshul Kundaje and William Greenleaf at Stanford University, her research revealed one of the largest maps of gene regulation during human development and used machine learning to show how regulatory proteins cooperate to regulate gene activity, and was published this year in Nature.

At LTRI, her lab is applying computational approaches to uncover how common developmental signals elicit diverse responses in different cell types and, eventually, whether these regulatory rules can be used to deliberately program cellular behaviour.

Dr. Jessa says the breadth of expertise at Sinai Health and LTRI was a major draw. During her visits to the institute, conversations with researchers and clinicians from fields outside her own changed the way she was thinking about her own work.

“During every conversation I was learning something new about other people’s research, but I was also seeing my own work through a different lens, with the questions people asked”

As she established her research program, Dr. Jessa is equally focused on building a collaborative lab culture. Drawing on mentorship experience that shaped her own career, she hopes to create an environment where trainees can pursue ambitious science while still supporting one another: “welcoming for everyone, but where each person can find their own way to thrive.”