BiG Talk: Pioneering chromatin landscapes in embryo development – epigenomic methods reveal how gene expression patterns are formed and maintained
October 8, 2026 @ 13:00 – 14:00 CEST
Professor Mattias Mannervik, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University.
Abstract
Understanding how chromatin state contributes to developmental trajectories remains central to deciphering cell specification and differentiation. In this talk, I will discuss how studying chromatin biology with genomic methods at the bulk and single-cell level informs on embryo development and formation of different cell types. Immediately after fertilization, the genome is transcriptionally quiescent. Maternally encoded pioneer factors reprogram the chromatin state and facilitate transcription of the zygotic genome. In Drosophila, transcription is initiated by the pioneer factor Zelda. While Zelda-occupied sites are enriched with histone acetylation, a post-translational mark associated with active cis-regulatory regions, the functional relationship between Zelda and histone acetylation remained unclear. We show that Zelda-mediated recruitment of the histone acetyltransferase CREB-binding protein (CBP) is essential for zygotic transcription. Further, using dual-modality nano-CUT&Tag, we profiled two antagonistic histone modifications—active H3K27ac and repressive H3K27me3—in thousands of single cells from Drosophila embryos across early lineage diversification and terminal differentiation. Joint embedding of both marks enabled robust cell-type classification and revealed increasing epigenetic specificity over developmental time. We ordered cells by developmental age and epigenomic similarity, and defined an epigenetic potential metric that visualizes repressive chromatin barriers as landscapes that predict transcriptional activity. These findings demonstrate that cell-type-specific deployment of H3K27ac and H3K27me3 sculpts epigenetic potential landscapes that help shape developmental gene expression patterns.
Biography
Mattias Mannervik is Professor of Molecular Developmental Biology at the Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University. By combining powerful Drosophila genetics with genomic technologies, his research focuses on how chromatin and transcription influence each other, and how the resulting gene expression patterns shape embryo development. His interest in transcriptional regulation began already during his undergraduate studies, and his Ph.D. work with Professor Göran Akusjärvi at Uppsala University focused on how adenoviruses use the host cell machinery to control transcription. He then turned to a model where genetics could be applied to studies of transcriptional control, and did his postdoctoral work in Professor Mike Levine´s laboratory at University of California, Berkeley, USA, where he studied transcriptional co-regulators in Drosophila embryo development. Returning to Sweden in year 2000, he established his independent laboratory at Stockholm University. Genetic screens and reverse genetic approaches uncovered novel regulators of gene expression in Drosophila embryos, and for more than 15 years genomic and epigenomic methods have been the cornerstone of his research. This has led to discoveries such as a unique histone 3 lysine 14 chromatin signature that underlies tissue-specific gene regulation, that gene regulation can occur independently of chromatin conformation, and that the CBP co-activator has an unexpected function in epigenetic gene silencing by Polycomb proteins.
Host: Agata Smialowska, NBIS (agata.smialowska@nbis.se)
Broadcast link (live event): https://lu-se.zoom.us/j/64561309877
The talk is sponsored by the NBIS course Epigenomics Data Analysis.
A recording will also be available on the NBIS YouTube channel.
info@nbis.se
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