Developmental Genetics and Neurobiology
We study how developmental programs generate cellular phenotypes in the brain, and how changes in these programs contribute to brain evolution and disease.
Our Research
Our research centres on the cerebellum, a brain region traditionally known for controlling movement and balance but increasingly recognized for its roles in cognition, emotion, social behaviour, and language. Containing about 80% of all the neurons in the human brain, the cerebellum has likely played critical roles in the evolution of human cognitive abilities, and its dysfunction is increasingly implicated in the pathology of neurodevelopmental disorders.
We investigate how genetic variants associated with autism spectrum disorders (ASD) and related neurodevelopmental disorders affect the development of cerebellar cells and whether human-specific aspects of cerebellum development are vulnerable to these variants. We also explore how genes with species- or clade-specific expression patterns contribute to cerebellum development and the establishment of its structure and function.
We employ a range of methods and approaches, including mouse genetic models, human iPSC-derived organoids, single-cell sequencing, spatial transcriptomics, CRISPR-based perturbations, enhancer reporter assays, and sparse or cell type-specific labeling of cellular morphology.
Our Values
We think boldly and work rigorously. We value curiosity, creativity, depth, perseverance, integrity, and transparency in how we do science.
We help each other grow. We teach, mentor, collaborate, and celebrate each other’s progress.
We value diverse perspectives. We believe different backgrounds, experiences, and ways of thinking fuel discovery.
Selected publications
Evolutionary perspectives on the development of the mammalian cerebellum: From cellular diversity to gene regulatory programs
Yamada, T., Sarropoulos, I., Sepp, M. et al. (2026)
Current Topics in Developmental Biology Link
The evolution of gene regulation in mammalian cerebellum development
Sarropoulos, I., Sepp, M., Yamada, T. et al. (2026)
Science Link
Cellular development and evolution of the mammalian cerebellum
Sepp, M., Leiss, K., Murat, F. et al. (2023)
Nature Link
Developmental and evolutionary dynamics of cis-regulatory elements in mouse cerebellar cells
Sarropoulos, I., Sepp, M., Frömel, R. et al. (2021)
Science Link
News
Congrats to Mariya Roy for defending her BSc thesis with the highest grade!
June 2026Mari presenting at the 14th International Symposium of the Society for Research on the Cerebellum and Ataxias in Nicosia, Cyprus, 15 -17 May 2026
May 2026Mari giving a keynote talk at the Comparative Brain Meeting in Paris, France, 27–30 April 2026
April 2026Mari presenting at the SFARI Investigator Meeting in New York, USA, 16-18 March 2026
March 2026Mari presenting at the Rare Disease Day Conference, Tallinn, Estonia, 2 March 2026
March 2026https://www.kliinikum.ee/harvikhaigused/harvikhaiguste-paeva-konverents-2026/
Welcome to the lab, Dr. Hanna Vihma!
March 2026Our review on cerebellar development in Current Topics in Developmental Biology
February 2026https://www.sciencedirect.com/science/chapter/bookseries/abs/pii/S0070215326000104?via%3Dihub
A major chapter of Mari’s postdoctoral work in the Kaessmann lab published in Science.
January 2026
The study was led together with co-first authors Dr. Ioannis Sarropoulos and Tetsuya Yamada. https:/…
Welcome to the lab, Dr. Kersti Lilleväli!
January 2026Estonian Research Council Grant
November 2025
We celebrate receiving a team grant from the Estonian Research Council, providing major national fun…
BSc students Nini Mzhavanadze and Mariya Roy join the group. Welcome!
November 2025Mari presenting at the annual conference of the Estonian Society of Human Genetics in Haapsalu, Estonia, October 30-31 2025
October 2025https://estshg.ut.ee/xxvii-teaduskonverents-haapsalus-30-31-oktoobril-2025/
The lab is launched!
October 2025
Annika Trei joins the group as Lab Manager, and Signi Ereline as Project Coordinator.
We also welco…
Mari presenting at the International Gene Forum in Tartu, Estonia, 9-10 September 2025
September 2025It's official!
July 2025Mari accepts the offer from the Institute of Genomics, University of Tartu, to join as an Associate Professor and Group Leader.
Contact
E-mail: m.sepp@ut.ee
Institute of Genomics: https://genomics.ut.ee/en
University of Tartu: https://ut.ee/en
