Mark Pownall

Three-dimensional genome reorganization foreshadows zygotic genome activation in Drosophila - Nature Genetics Pico-C, a low-input Micro-C approach, reveals that dynamic three-dimensional genome folding precedes zygotic genome activation in Drosophila.

Excited to share my PhD work!

The question: How is genome organization established? Here, we developed a low-input Micro-C method, Pico-C, and used it to map chromatin architecture across early stages of fly development.

Here’s a quick Blue-torial 🙂 (1/n)

www.nature.com/articles/s41...

Our Mini Review went online last night in Current Opinion in Genetics & Development
"Block copolymer concepts of how transcription organizes the stem cell genome"
doi.org/10.1016/j.gd...

Fig. 1: Stem cell–typical organization of the genome and transcription, and the block copolymer sorting concept.

Multiscale structure of chromatin condensates explains phase separation and material properties The structure and interaction networks of molecules within biomolecular condensates are poorly understood. Using cryo–electron tomography and molecular dynamics simulations, we elucidated the structur...

@science.org 🧬🔬 Multiscale structure of #chromatin condensates explains phase separation and material properties | Science www.science.org/doi/10.1126/... @janhuemar.bsky.social et al.

Here is a copy of last year's Twitter thread explaining our preprint - jump to (21) for the new stuff 👀

Synergy between cis-regulatory elements can render cohesin dispensable for distal enhancer function

now revised and journal accepted at www.science.org/doi/10.1126/...

🧵👇

NIPBL dosage shapes genome folding by tuning the rate of cohesin loop extrusion Cohesin loop extrusion is a major driver of chromosome folding, but how its dynamics are controlled to shape the genome remains elusive. Here we disentangle the contributions of the cohesin cofactors ...

New preprint with @gfudenberg.bsky.social

We find the rate of cohesin loop extrusion in cells is set by NIPBL dosage and tunes many aspects of chromosome folding.

This provides a molecular basis for NIPBL haploinsufficiency in humans. 🧵👇

www.biorxiv.org/content/10.1...

Our first expansion microscopy results. Imaged today on "normal" Zeiss LSM 900, revealing chromatin and RNA polymerase II clusters at an unreal level of detail.

Our PhD student @mofrawe.bsky.social learned the protocol from amazing @mpownall.bsky.social 🙏

Months of preparation are paying off now!

Looking good!!

The nuclear periphery confers repression on H3K9me2-marked genes and transposons to shape cell fate - Nature Cell Biology Marin et al. report the role of lamin proteins and the lamin B receptor (LBR) in chromatin positioning at the nuclear periphery. Knockout of all lamins and LBR in mouse embryonic stem cells leads to h...

Another paper bluetorial! Today: how does the spatial location of genes influence their function? (1/n) www.nature.com/articles/s41...

Catalytic-dependent and independent functions of the histone acetyltransferase CBP promote pioneer-factor-mediated zygotic genome activation Marsh, Pirogov, et al. use the early Drosophila embryo to demonstrate that the conserved histone acetyltransferase CBP is required for pioneer-factor-mediated transcriptional activation of the zygotic...

Excited to share our new paper in @cp-molcell.bsky.social Molecular Cell: "Catalytic-dependent and independent functions of the histone acetyltransferase CBP promote pioneer-factor-mediated zygotic genome activation" — the big part of my PhD! www.cell.com/molecular-ce...

Microscopy methods for the in vivo study of nanoscale nuclear organization Eukaryotic genomes are highly compacted within the nucleus and organized into complex 3D structures across various genomic and physical scales. Organization within the nucleus plays a key role in gene...

First paper from the Pownall lab calls for a first post on bluesky! Check out our mini review on nanoscale imaging of the nucleus in vivo. We are excited to address some of these open questions and technical challenges through future work from the lab—stay tuned!
portlandpress.com/biochemsoctr...