Mari Sepp is an associate professor at the University of Tartu in Estonia. She received her doctoral degree from Tallinn University of Technology, Estonia, and completed her postdoctoral training at Heidelberg University, Germany.

During her doctoral research, Sepp identified TCF4 as an activity-regulated transcription factor in neurons and demonstrated how autism-associated mutations in TCF4 impair its function. In her postdoctoral research, she compared cerebellum development across different mammalian species, revealing both conserved and human-unique aspects of its cellular dynamics and gene regulatory programs. Guided by this work, as a junior PI, Sepp seeks to employ mouse and human model systems to investigate how mutations in autism spectrum disorder-associated genes affect cerebellum development.

Sepp has been awarded the Otto Schmeil Prize from the Academy of Sciences of the State of Baden-Württemberg. She was selected as a SFARI Bridge to Independence fellow in 2024 and as an EMBO Installation grantee in 2025.