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Reposted by Maitreyi Das

Harmit Singh Malik @harmitmalik.bsky.social · 3d

I am leaving Rochester NY after attending the retirement fest of four giants in the field of evolutionary biology including my PhD advisor. This visit gave me a chance to revisit old haunts and reflect on my own somewhat unlikely origin story. 1/n

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Reposted by Maitreyi Das

EvolDir @evoldir.bsky.social · 4d

UMass Boston seeks a tenure-track Assistant Professor in microbial ecology, starting September 1, 2026. Apply by December 1, 2025. Details: http://www.umb.edu/academics/csm/biology #job

Biology - UMass Boston

www.umb.edu

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Reposted by Maitreyi Das

Journal of Cell Science @jcellsci.bsky.social · 6d

Read more about this research in our ‘First person’ interview with Bethany Campbell: journals.biologists.com/jcs/article/...

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Reposted by Maitreyi Das

Journal of Cell Science @jcellsci.bsky.social · 6d

Bethany Campbell, Maitreyi Das @daslabpombe.com and colleagues discover that endocytic patch dynamics are differentially regulated at distinct cell sites in fission yeast.
Highlight: journals.biologists.com/jcs/article/...
Article: journals.biologists.com/jcs/article/...

Figure showing that type I myosin Myo1 regulates endocytic patch dynamics at the cell ends, division site and the cell sides.

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Reposted by Maitreyi Das

Dr. Kat Napaaqtuk❄️ @napaaqtuk.bsky.social · 11d

Comment period ends on Monday for a proposed rule change that would terminate student visas after 4 years. It also puts limits on exchange visitors and reps of foreign media, and shortens the length of time at the end of the visa from 60 days to 30 days.

www.federalregister.gov/documents/20...

Establishing a Fixed Time Period of Admission and an Extension of Stay Procedure for Nonimmigrant Academic Students, Exchange Visitors, and Representatives of Foreign Information Media

Unlike most nonimmigrant classifications, which are admitted for a fixed time period, aliens in the F (academic student), J (exchange visitor), and most I (representatives of foreign information media...

www.federalregister.gov

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Reposted by Maitreyi Das

Mark Peifer (He, him) @peiferlabunc.bsky.social · 11d

Here's my comment--join me. This would effectively remove foreign PhD students and postdocs from our labs. please share

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Maitreyi Das @daslabpombe.com · 12d

Looks like year 2 grad students can no longer apply for the NSF GRFP. I hope I am wrong.
www.nsf.gov/funding/oppo...

NSF Graduate Research Fellowship Program (GRFP)

www.nsf.gov

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Maitreyi Das @daslabpombe.com · Sep 6

It is unclear how NE fenestration occurs. We find a potential for branched actin in fenestration. Branched actin promotes NE break down in starfish oocytes. Our findings suggest that branched actin plays a conserved role in mitosis. For more see our preprint. 10/end
www.biorxiv.org/content/10.1...

Role of the Arp2/3 Complex in Regulating Mitotic Entry and Progression in S. pombe

Fission yeast undergoes closed mitosis, wherein chromosome segregation occurs inside an intact nucleus. The microtubule organizing center, Spindle Pole Body (SPB) is duplicated in the G2 phase followe...

www.biorxiv.org

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Maitreyi Das @daslabpombe.com · Sep 6

Interestingly, cells that do enter mitosis despite CK666 treatment, show aberrant SPB interaction with the actin ring leading to spindle and nuclear division defects. This suggests that the SPB has an affinity for actin and in the absence of branched actin binds the actin ring instead. 9/

Atb2-mCherry labeled spindle microtubule dynamics in DMSO or CK666-treated synchronized cdc25-22 cells post cell cycle release. Severe bending of microtubules is seen in CK666-treated cells.

3D-reconstruction over time of SPB labeled with cdc11-GFP and the actomyosin ring labeled with Rlc1-tdTomato in CK666-treated cells. One SPB aberrantly interacts with the actin ring and remains at that plane while the other SPB moves towards the cell ends during anaphase.

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Maitreyi Das @daslabpombe.com · Sep 6

Branched actin is known to remodel membrane. If it helps fenestration on the NE we should see branched actin elements on the NE and near the SPB. Indeed, she found Fimbrin and Arp2/3 components on the NE and near the SPB. 8/

Fim1-GFP localizes adjacent to Ppc89-mCherry 2 minutes prior to onset of mitosis

Fim1-GFP localizes to Bqt4-mCherry labeled NE.

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Maitreyi Das @daslabpombe.com · Sep 6

If CK666 is required for NE fenestration, treating the cells with CK666 should not display mitotic defects. Indeed, in prophase-arrested nda3-KM11 mutants, treatment with ck666 followed by prophase release did not show any mitotic defects. 7/

Loss of branched actin after preprophase arrest does not block mitosis when released. Mitotic progression in nda3-KM311 cells after release from preprophase arrest in DMSO or CK666-treated cells. Quantification of the percentage of cells that progress to mitosis at respective time intervals after the release from prophase arrest.

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Maitreyi Das @daslabpombe.com · Sep 6

She asked if this is because the fenestra fails to form in these cells. Indeed, CK666 treated cells retain higher levels of NLS-GFP in the nucleus a hallmark of fenestration defect. 6/

Representative images display accumulation of NLS GFP in the nucleus in DMSO or CK666 treated cut12.1 NLS-GFP strain grown at 36°C for 4 and 5 hours. CK666 treated cells show higher levels of NLS-GFP.

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Maitreyi Das @daslabpombe.com · Sep 6

Cut11 recruitment defects typically indicate failure to inset the SPB in the NE. Just before SPB insertion during fenestration, the SUN domain protein Sad1 forms a ring framing the fenestra. Ck666-treated cells fail to form this ring as seen with Structured illumination microscopy. 5/

Redistribution of Sad1-mCherry and Cut11-GFP in synchronized cdc25-22 released into the cell cycle for 30 mins after DMSO or CK666 treatment. CK666 treated failed to form Sad1 and Cut11 rings.

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Maitreyi Das @daslabpombe.com · Sep 6

She found that on CK666 treatment, the SPB often failed to recruit the Polo-like kinase Plo1 and the SPB docking protein Cut11. 4/

Plo1-GFP localization in DMSO or CK666-treated synchronous cdc25-22 cells released into the cell cycle. Plo1-GFP localization at the SPB is failed in CK666 phenotype 1, delayed in phenotype 2 and recruited earlier but the mitotic onset is in phenotype 3.

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Maitreyi Das @daslabpombe.com · Sep 6

We saw similar defects in mutants of arp3 or actin-bundling protein fimbrin. Fission yeasts undergo closed mitosis and the MTOC or spindle pole body (SPB) duplicates in interphase and just before mitotic onset, is inserted into a fenestra on the nuclear envelope and spindle microtubules nucleate. 3/

DMSO or CK666 treated synchronized cdc25-22 fimΔ cells 30 and 60 minutes after release from cell cycle arrest. bqt4-mCherry labels NE and atb2-mCherry labels microtubules. Red arrowhead shows monopolar spindles. Fimbrin deletion cells show mitotic defects regardless of CK666 treatment.

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Maitreyi Das @daslabpombe.com · Sep 6

We noticed that fission yeast cells treated with the Arp2/3 complex inhibitor CK666 often failed mitotic entry. Dhanya confirmed this finding and it was all the clearer in cell-cycle synchronized cells, where CK666 cells often failed to enter mitosis or did so with a significant delay. 2/

Branched actin inhibition blocks or delays mitotic entry. Time-lapse microscopy of DMSO or CK666-treated cdc25-22 synchronized cells released from cell-cycle arrest. Cut11-GFP marks SPB.

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Maitreyi Das @daslabpombe.com · Sep 6

Our latest preprint on the role of the Arp2/3 complex in mitotic entry is now available @biorxiv. This work was done by Dhanya Kalathil, a very talented postdoc in my lab. The story started in 2019 when we were investigating the role of branched actin in cytokinesis. 1/

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Maitreyi Das @daslabpombe.com · Sep 3

Congratulations Katherine and the Aird lab.

Maitreyi Das @daslabpombe.com · Aug 29

Our latest is now available @jcellsci.bsky.social. The final research article from Bethany Campbell's thesis work. Endocytic patch dynamics are differentially regulated at distinct cell sites in fission yeast.
doi.org/10.1242/jcs....

Endocytic patch dynamics are differentially regulated at distinct cell sites in fission yeast

Endocytosis promotes polarity and growth in eukaryotes. In Schizosaccharomyces pombe fission yeast, endocytosis occurs at the polarized cell ends and division site and at the non-polarized cell sides....

doi.org

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Gautam Dey @gautamdey.bsky.social · Aug 27

Final year PhD students, I know you’re desperately trying to finish experiments/revisions/submissions/write a thesis & just survive - but please spare a few minutes to apply to your dream postdoc labs.

It easily takes A YEAR from first contact, even if everything goes to plan on both sides.

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Reposted by Maitreyi Das

Eric Surette @ericsurette.bsky.social · Aug 26

Hello Bluesky: Long time listener, first time poster! Excited to share the first publication of my Ph.D. work studying the development of appendage shapes in @plosbiology.org! The zebrafish caudal fin is quite distinctive, and we examine the timing and mechanisms of how its shape might come to be!

PLOS Biology @plosbiology.org · Aug 26

Caudal fins show great variation in shape between diverse fish species. New research reveals that #developmental cues in embryonic tissues involving the Sonic hedgehog pathway imprint fin #morphology, highlighting a critical window for modulating appendage morphology. 🧪
plos.io/4mydLnA

Brightfield image of an adult zebrafish caudal fin displaying a “truncate” shape and aberrant pigment pattern. This individual was exposed to transient overexpression of transgenic sonic hedgehog a at 2 days post fertilization, resulting in increased growth of rays at the center of the fin and disruption of the normally horizontal pigment stripes. Credit: Eric Surette and Stephanie Robinson.

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PLOS Biology @plosbiology.org · Aug 26

Caudal fins show great variation in shape between diverse fish species. New research reveals that #developmental cues in embryonic tissues involving the Sonic hedgehog pathway imprint fin #morphology, highlighting a critical window for modulating appendage morphology. 🧪
plos.io/4mydLnA

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Maitreyi Das @daslabpombe.com · Aug 26

ASCB Cell Bio 2025, is in Philadelphia 12/6-10. Apply for a Familycare Grant by 9/3. These flexible awards ($500) can be used towards any eligible family care expense that makes it easier for you to attend the Annual Meeting. www.ascb.org/grants-award...

Travel Grants - ASCB

2025 Cell Bio Travel Grant Applications Will Be Open August 1 thru September 3 Notes: 1. Applicants may only receive one of the following travel grants. 2. If selected, recipients will need to provide...

www.ascb.org

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Reposted by Maitreyi Das

Addgene @addgene.bsky.social · Aug 21

Attention yeast researchers! This new study benchmarks the latest fluorescent proteins in yeast — comparing brightness, stability, pH robustness, and more. The characterized plasmids are available at Addgene.
https://twp.ai/4ipK7q

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Reposted by Maitreyi Das

Alex Merz 🇺🇸🇨🇦🇺🇦 @merz.bsky.social · Aug 16

This looks really interesting. It is going to require some time and attention…

Optical Control of Membrane Viscosity Modulates ER-to-Golgi Trafficking

The lipid composition of cellular membranes is highly dynamic and undergoes continuous remodeling, affecting the biophysical properties critical to biological function. Here, we introduce an optical a...

pubs.acs.org

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