Mikael Marttinen
mmarttinen.bsky.social
Mikael Marttinen
@mmarttinen.bsky.social
Postdoc researching gene regulation in disease || Tampere University and EMBL
This was a long, fun project, which took the effort of many talented people (Sara Lobato, Umut Yildiz, @anniquec.bsky.social et al.) from the Zaugg and Noh labs! @embl.org @unibas.ch

A detailed protocol is in the works for release. For now, check out the paper!
May 26, 2025 at 9:33 AM
Constructing temporal GRNs revealed keys TFs at different stages of development and how perturbation of key lineage TFs shift developmental trajectories of cells (8/)
May 26, 2025 at 9:33 AM
Lastly, SUM-seq is an ideal match for arrayed screens. We show this in a CRISPRi and CRISPRa, modulating key lineage TFs (GATA2/SOX17/NR4A2) in hiPSCs over a time course (0,4,12, and 18 DIV) of spontaneous differentiation (7/)
May 26, 2025 at 9:33 AM
To demonstrate use of SUM-seq in primary samples, we profiled PBMC-derived naive CD4+ T cells differentiated into Th0, iTregs, Th2, Th1, Th17 and IFN-β-activated subsets. With this, we provide insight on the TF landscape driving T cell subset differentiation (6/)
May 26, 2025 at 9:33 AM
Can the GRN help understand disease biology? Yes! GRN genomic regions were enriched for heritability of immune-related diseases (incl. IBD/UC/CD). Taking a step further, we link an intronic SNP in CD40, putatively targeted by ISGF3, to CD40, PLTP, NEURL2 and SLC35C2 (5/)
May 26, 2025 at 9:33 AM
With SUM-seq, we first define temporal GRN dynamics of mac. M1/M2 polarization. One of the notable insights made was how STAT1 transitions from its homodimer-driven chromatin remodelling functions during early M1 polarization to an ISGF3-driven response at later phases (4/)
May 26, 2025 at 9:33 AM
The method is optimised to mitigate possible cross modality (ATAC <-> RNA) and within modality (sample <-> sample) hopping, while still providing high quality data (3/)
May 26, 2025 at 9:33 AM
To address this, we present SUM-seq - embedding two-step combinatorial indexing to snATAC+RNA library construction. Combining sample-specific indexes with 10X droplet-barcoding permits significant scaling of number of samples and cells assayed in a single lane! (2/)
May 26, 2025 at 9:33 AM
Single-cell multiomics lets us infer cell type-specific GRNs: key to deciphering cell function in health/disease. GRNs however are dynamic, and inference demands data capturing a spectrum of cell states. But current multiomic assays are limited by scalability or data quality (1/)
May 26, 2025 at 9:33 AM