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

Thesis defence Max

Max was one of the first Vastenhouw Lab PhD students. This month, he has successfully defended his thesis. We celebrated his achievement with cheese fondue and a few drinks!
We wish Max all the best for his future research!

Lab Photo Session 2017

Julia Eichhorn from the CBG Photolab braved the freezing cold with us for our lab photo. Look at the snow!

There's also a photo of Mate taking a photo of Julia taking a photo of Edlyn. To avoid overly frozen smiles during our individual headshots, we did head back inside after all. Thanks Julia, great photos!

Happy holidays!

The Vastenhouw lab wishes all of you a great holiday season and a happy new year

To celebrate the holiday season, we gathered at Nadine’s home earlier this month to celebrate Dutch Santa Claus (Sinterklaas). This included a ‘white elephant gift exchange’ in which a tea towel became the source of a heavy battle. We mixed it up with some Australian culture and enjoyed a delicious “Aussie Barbie” lunch thanks to Shai and his advanced BBQ-ing skills. Meanwhile, we got a gift every day in the lab, as well. Sabrina made a typical German Advents calendar for which she – atypically - used pipet tip boxes. The boxes were filled with goodies by all of us and each day in December we could open one of these boxes. We got face masks, cookie cutters and two remote controlled cars (!!), but mostly we ate a lot of candy. We wish you all a wonderful end of the year and a happy, healthy and successful 2017.