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Reposted by Jana Helsen

Linda Horianopoulos @linder-surprise.bsky.social · Sep 5

We often talk about THE whole genome duplication in yeasts, but we find new evidence of additional whole genome duplications in other yeast species!

Check out this preprint led by @kylethedavid.bsky.social www.biorxiv.org/content/10.1...

Discovery of additional ancient genome duplications in yeasts

Whole genome duplication (WGD) has had profound macroevolutionary impacts on diverse lineages, preceding adaptive radiations in vertebrates, teleost fish, and angiosperms. In contrast to the many know...

www.biorxiv.org

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Reposted by Jana Helsen

Gerlich Lab @gerlichlab.bsky.social · Sep 3

1/ New preprint alert!
In collaboration between the Rosen, Redding, Collepardo-Guevara & Gerlich labs, we uncover a surprising principle of chromosome organisation: electrostatic repulsion positions centromeres at the chromosome surface during mitosis.
🔗 doi.org/10.1101/2025...

An electrostatic repulsion model of centromere organisation

During cell division, chromosomes reorganise into compact bodies in which centromeres localise precisely at the chromatin surface to enable kinetochore-microtubule interactions essential for genome se...

doi.org

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Reposted by Jana Helsen

Ben Larson @blarson.bsky.social · Aug 26

What could be more exciting than watching Euplotes scurry around under the microscope? How about adding some raptorial predation by supergiant cannibal cells?

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

Video by Vittorio Boscaro.

1/n

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Gautam Dey @gautamdey.bsky.social · Aug 7

Want to acquire #ExM images like this and help us understand the true extent of cytoskeletal diversity across the tree of life? This position might be for you!

embl.wd103.myworkdayjobs.com/en-US/EMBL/j...

With @dudinlab.bsky.social
@embl.org @biology-unige.bsky.social @moorefound.bsky.social

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Reposted by Jana Helsen

Siân Culley @superresolusian.bsky.social · Aug 7

Hello! Very excited to share our latest preprint, which is great news for us but terrible news for any diehard fans of PSNR and SSIM as image quality metrics in microscopy... (1/5)
www.biorxiv.org/content/10.1...

Image quality metrics fail to accurately represent biological information in fluorescence microscopy

Image processing methods offer the potential to improve the quality of fluorescence microscopy data, allowing for image acquisition at lower, less phototoxic illumination doses. The training and evalu...

www.biorxiv.org

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Reposted by Jana Helsen

Tera Levin @teralevin.bsky.social · Aug 5

I'm excited to announce our new biorxiv preprint, wherein we investigate the evolution of the weirdest genetic locus I've ever seen! Behold the tgr genes of the social amoeba, which mediate self/non-self discrimination during facultative multicellularity 🐅 🧵 1/
www.biorxiv.org/content/10.1...

Hypermutable hotspot enables the rapid evolution of self/non-self recognition genes in Dictyostelium

Cells require highly polymorphic receptors to perform accurate self/non-self recognition. In the amoeba Dicytostelium discoideum, polymorphic TgrB1 & TgrC1 proteins are used to bind sister cells and e...

www.biorxiv.org

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Reposted by Jana Helsen

Marko Kaksonen @kaksonen.bsky.social · Jul 10

How does evolution shape ancient cellular processes? Our new paper uncovers the mosaic evolution of conserved and diverging endocytic traits in fungi!

www.cell.com/current-biol...

Mosaic evolution of clathrin-mediated endocytosis in fungi

Picco et al. take an evolutionary approach to study clathrin-mediated endocytosis in a fungal clade and discover that the process is evolving in a mosaic fashion. The early phase of endocytosis has sh...

www.cell.com

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Reposted by Jana Helsen

Max Haase @maxhaase.bsky.social · Apr 25

It’s out! The evolutionary origins of yeast point centromeres uncovered!

“Ancient co-option of LTR retrotransposons as yeast centromeres”

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

Ancient co-option of LTR retrotransposons as yeast centromeres

The evolutionary origins of the genetic point centromere in the brewer's yeast Saccharomyces cerevisiae, a member of the order Saccharomycetales, are still unknown. Competing hypotheses suggest that t...

www.biorxiv.org

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Reposted by Jana Helsen

Shashank Shekhar lab @sshekhr.bsky.social · Apr 2

📢Excited to share our new paper in Nature Physics
@naturephysics.bsky.social: Cooperative hydrodynamics accompany multicellular-like colonial organization in the unicellular Stentor!

How do single-celled organisms benefit from teamwork? Let’s dive in! #Multicellularity nature.com/articles/s41...?

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Jana Helsen @helsenjana.bsky.social · Apr 3

Super nice to see this out! Congrats Hashim!

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Hashim @hashimreza.bsky.social · Apr 3

My postdoctoral work on the non-canonical role of an autophagy-related protein at the spindle pole body (SPB) is now out in @plosbiology.org (doi.org/10.1371/jour...).

doi.org

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Diorge Souza @diorgeps.bsky.social · Feb 8

Happy to share our paper’s final version on the evolution, structure, and membrane binding / remodeling of Asgard ESCRT-III proteins! And my first 🦋 post! www.science.org/doi/10.1126/...

Asgard archaea reveal the conserved principles of ESCRT-III membrane remodeling

Asgard archaea have two ESCRT-III subunits with the conserved traits that drive stepwise membrane remodeling in eukaryotes.

www.science.org

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Jana Helsen @helsenjana.bsky.social · Jan 17

Thank you, that's very nice to hear! 😁

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Jana Helsen @helsenjana.bsky.social · Jan 17

Thank you Max! 😁

Jana Helsen @helsenjana.bsky.social · Jan 17

This rewarding project came to fruition with the help of my amazing colleagues @gsherloc.bsky.social, @gautamdey.bsky.social, and @kausthubh.bsky.social, and with the support of @embl.org, Stanford University, and the Life Science Alliance. (8/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

Our study challenges the traditional view of centromere drive as the sole driver of centromere evolution. We propose a multi-faceted model involving drift and selection during both mitosis and meiosis, shaped by constraints imposed by the kinetochore interface. (7/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

Centromere transitions aren't random!

Our findings suggest that the kinetochore interface dictates which centromere changes are tolerated. Coevolution between the kinetochore and centromere sequences likely drives these constrained transitions. (6/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

Centromere variants can also spread through populations via sexual reproduction. In budding yeasts, microhomology-mediated mutations seem to be the key driver in the emergence of these novel centromere variants. (5/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

Centromere transitions turn out to be a gradual, step-by-step process. Through simulations and in vivo centromere function experiments, we show that selection plays a crucial role in driving these changes! (4/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

We developed a new tool, PCAn 🔍, to systematically map point centromeres across budding yeasts, revealing remarkable centromere variation! (3/8)

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Jana Helsen @helsenjana.bsky.social · Jan 17

Unlike genes, species with monocentric chromosomes possess multiple centromeres, one on each chromosome. This makes centromere evolution conceptually quite different from gene evolution.

Our work aimed to shed light on the fundamental evolutionary principles underlying centromere transitions. (2/8)

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Reposted by Jana Helsen

Harmit Singh Malik @harmitmalik.bsky.social · Jan 17

Cool paper on evolutionary constraints and trajectories shaping point centromere evolution in budding yeasts by @helsenjana.bsky.social @gautamdey.bsky.social @gsherloc.bsky.social

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

Centromeres evolve progressively through selection at the kinetochore interface

During mitosis, stable but dynamic interactions between the centromere DNA and kinetochore complex enable accurate and efficient chromosome segregation. Even though many proteins of the kinetochore ar...

www.biorxiv.org

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Jana Helsen @helsenjana.bsky.social · Jan 17

Centromere evolution isn't a sudden switch!

Our study shows centromere transitions are a step-by-step process driven by a combination of drift and selection. Discover how the kinetochore interface shapes this gradual change in our new preprint 🥳 doi.org/10.1101/2025.01.16.633479 🧵(1/8)

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Jana Helsen @helsenjana.bsky.social · Dec 26

Subconscious motivation, I promise, but I was indeed somewhat intrigued by those covers as a child 😂

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Reposted by Jana Helsen

Gautam Dey @gautamdey.bsky.social · Dec 25

Happy holidays from the #DeyLab and 🥂 to a wonderful 2025!

(If you haven’t seen one of our cards before, you’re thinking, oh that’s sort of vaguely unsettling, YES! And we are here for it 😊)

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