eLife Paper on Refractive Index Matching in Live Imaging

Microscopes are optimized to give the clearest images, taking great care of all optical components along the light path. This has lead to a situation where the transition between a live sample and the surrounding liquid becomes the biggest imperfection in the optical path.

In this MPI-CBG/MPI-PKS/CSBD collaboration, lead by Tobias Boothe from the Rink lab, we show a simple but highly effective procedure to minimize the optical imperfection at the sample/medium interface. The technique is based on OptiPrep (chemical name: iodixanol), which can be ordered and used in any biological laboratory without any unusual equipment. Our technique worked with no toxicity or other problems in whole animals, primary cells, cell lines, as well as organoids.

Find our paper online with eLife.

Máté at the Zebrafish Meeting in Hungary

July 3rd – 7th, 2017: Máté attended the 10th European Zebrafish Meeting in his hometown, Budapest, and gave a talk in the Genomics/Epigenetics session. The conference brought together the ever-growing zebrafish community (over 500 participants) and covered a wide range of topics. Those who missed it will have to wait until 2020, when the next EZM takes place in Prague.

 

 

Edlyn at MPI-CBG Postdoc Retreat

Edlyn attended the 7th Annual MPI-CBG Postdoc Retreat, which took place in the beautiful and picturesque Tisá, Czech Republic, from 19th to 21st of June, 2017.

The three-day retreat included talks (and elevator pitches) from fellow postdocs at the institute & invited external speakers:

  • Dr. Simon Reber (Humboldt-Universität, Berlin),
  • Dr. Elvan Boke (Centre for Genomic Regulation, Barcelona),
  • Dr. Selina Wray (University College London),
  • Dr. Adrian Raga (Katholieke Universiteit Leuven),
  • Dr. Olof Idevall-Hagren (Uppsala University);

and talks from our very own: Dr. Jacqueline Tabler and Dr. Christoph Zechner.

The retreat was scientifically enriching and also featured a hiking trip in Bohemian Switzerland, through the sandstone rocks of the Tisá Walls.

2017-06-20 15.48.04     

eLife paper on ZGA timing: activator-repressor competition

Our study demonstrating how repressors (histones) and activators (transcription factors) jointly control transcription in the zebrafish embryo is now available online: Competition between histone and transcription factor binding regulates the onset of transcription in zebrafish embryos. Joseph et al. eLife (2016)

Competition Model

In this study, lead by Shai Joseph (Vastenhouw Lab) and carried out collaboratively with the Shevchenko and Zaburdaev lab, we could quantitatively address a long-standing question: how is the timing at which transcription starts in embryos controlled?

By a combination of quantitative, molecular, and functional techniques, we found that the two most prominent hypotheses, the "depleted repressor" and the "increasing activator" models, can be unified in a competition model. Here, repressing histones and activating transcription factors go head-to-head competing for access to DNA target sites.

Additionally, the nuclear-to-cytoplasmic ratio - often defined in the number of genomes in an embryo - resurfaced as a key concept, though in the form of a volume ratio between cell nuclei and overall cytoplasm. While the global concentration of not DNA-bound histones did not change at the time of transcription onset, we detected a marked decrease in the concentration of not DNA-bound histones specifically within cell nuclei.

 

BioRxiv: Histone and transcription factor binding competition

A preprint for our latest work is now on BioRxiv: “Competition between histone and transcription factor binding regulates the onset of transcription in zebrafish embryos”. The lead author of this study is Shai, with lots of support from within the Vastenhouw lab as well as the Zaburdaev (MPI-PKS) and Shevchenko labs (MPI-CBG).

You can go and read the preprint here: http://biorxiv.org/content/early/2017/04/13/125716

Segmented Cells

FISHing fish, explained on thenode

Our recent publication is covered in a piece on FISHing fish. Check out the description and a bit of a behind-the-scenes insight into of the paper!

Link to post on thenode

Paper reference:

Stapel, L Carine; Lombardot, Benoit; Broaddus, Coleman; Kainmueller, Dagmar; Jug, Florian; Myers, Eugene W.; Vastenhouw, Nadine L.
Automated detection and quantification of single RNAs at cellular resolution in zebrafish embryos
Development, 143, no. 3, pp. 540-546, (2016)