Tetsuya Yamada

@tyamadat.bsky.social

PhD student @UniHeidelberg | Kaessmann lab | UTokyo alumn

Co-option of certain transposable elements as regulatory elements in specific cerebellar cell states, e.g. HERVL in rhombic lip–derived neuroblasts. Led by awesome Tetsuya @tyamadat.bsky.social, together with @ioansarr.bsky.social and @kaessmannlab.bsky.social

Tetsuya Yamada@tyamadat.bsky.social · 7d ago

Our manuscript on the co-option of TEs as cerebellar CREs is now officially published in @natcomms.nature.com! Huge thanks to @kaessmannlab.bsky.social @marisepp.bsky.social, and @ioansarr.bsky.social for the fantastic collaboration throughout this project! www.nature.com/articles/s41...

Exciting news 📣 The first preprint from @grandlab.bsky.social is out 🧬 How are essential genes controlled? By rapid degradation and recovery of TFs alone or in combination, we show that essential genes rely on a single dominant TF, despite dense co-binding. www.biorxiv.org/content/10.6...

Essential genes are dominantly activated by single transcription factors

Cell viability depends on the precise expression of essential genes, which are controlled by CpG-island (CGI) promoters densely bound by transcription factors (TFs). This has led to the prevailing model that TFs cooperate to ensure ubiquitous expression. Here, using rapid and reversible single and combinatorial degradation in murine stem cells, we systematically dissect the regulatory interactions between five key TFs. We uncover an unexpectedly specific architecture in which regulatory dominance, rather than cooperation, is the prevailing mode, where individual TFs autonomously drive chromatin opening and gene activation at largely distinct promoters. Cooperative regulation occurs at a minority of sites with antagonistic or synergistic outcomes modulated by the interplay between nucleosome positioning and TF sensitivity to chromatin. This logic is recapitulated at synthetic sequences and reflected in human genetic variation. These findings reveal that single TFs dominantly activate distinct sets of CGI-linked genes, including essential genes, across development, homeostasis, and disease. ### Competing Interest Statement The authors have declared no competing interest. DFG, GR 6341/2-1, 556634773

biorxiv.org

Why do schizophrenia GWAS signals look so flat across the genome? In our recent preprint, we explored why psychiatric disorders — and, more broadly, brain-related traits involving the central nervous system — appear to have unusual genetic architectures. 🧵1/n

Bild

We built the first complete genome for the common marmoset, fully resolving regions that were previously missing: centromeres, acrocentric short arms, and more. A new reference genome for anyone working with marmosets. This was an awesome collaborative effort & I’m grateful to all my co-authors! 🧬

bioRxiv Genomics@biorxiv-genomic.bsky.social · 4mo ago

A Complete Genome for the Common Marmoset https://www.biorxiv.org/content/10.64898/2026.03.25.713844v1

MPRAs are the gold-standard tool for measuring how DNA sequences drive gene expression and prioritizing variant effects. In this preprint we asked: does it matter WHERE you place a variant in an MPRA? Spoiler: yes, and it might lead you to miss disease-causing variants. 1/6 doi.org/10.64898/202...

Position-dependent variant effects reveal importance of context in genomic regulation

Gene expression is governed by the DNA sequence, which is read out through complex interactions between transcription factors (TFs), co-activators, and chromatin. Massively Parallel Reporter Assays (MPRAs) provide a high-throughput framework for functionally characterizing how regulatory DNA sequences impact the expression of a model gene. MPRAs have also proven to be useful for measuring the effects of genetic variation, where each allele is typically tested in the center of ~200 bp of genomic context cloned into the MPRA, but the impact of variant position and local context remains largely unexplored. In this study, we systematically investigate how shifting the position of a variant within an MPRA probe influences its regulatory activity using models that predict expression in MPRAs from DNA sequence. We find that while the direction of variant effects is usually preserved across positions, the magnitude of expression changes can vary substantially depending on where the variant is placed within the construct. This positional bias appears to be largely explained by the strong position-dependent activity of TFs whose binding the variants perturb. In a subset of cases, interactions consistent with cooperativity between TFs also contribute to position-specific effects. ~1% of variants appear to disrupt RNA polymerase III (Pol III) promoters within Alu elements, resulting in position-specificity because both A and B boxes are required for function and exclusion of either motif due to window shifts disrupts the variants' effects. However, we saw little evidence to support the hypothesis that the positional dependence of variant effects resulted from the redundancy of motifs. Overall, our study demonstrates the complexity of cis-regulatory grammar and how it can confound the interpretation of regulatory variants. ### Competing Interest Statement R.T. has filed intellectual property related to MPRA and MPRA models. The other authors declare no competing interests.

biorxiv.org

Inhibitory neurons are among the most transcriptomically diverse class of neurons in the CNS, with some brain regions having 60+ distinct cell types. Do humans share the same repertoire as rodents? Birds? Fish? 1/13

New Perspective form Rory Maizels & me: "Gene regulatory networks: from correlative models to causal explanations" Gene regulatory networks are supposed to give us mechanistic explanations of development, so why are we drowning in 'hairballs' of statistical correlations? rdcu.be/e7zx7

Gene regulatory networks: from correlative models to causal explanations

Nature Reviews Genetics - In this Perspective, Maizels and Briscoe discuss the limitations of current models of gene regulatory networks and outline solutions to harness data abundance without...

rdcu.be