KLI Colloquia are informal, public talks that are followed by extensive dissussions. Speakers are KLI fellows or visiting researchers who are interested in presenting their work to an interdisciplinary audience and discussing it in a wider research context. We offer three types of talks:

1. Current Research Talks. KLI fellows or visiting researchers present and discuss their most recent research with the KLI fellows and the Vienna scientific community.

2. Future Research Talks. Visiting researchers present and discuss future projects and ideas togehter with the KLI fellows and the Vienna scientific community.

3. Professional Developmental Talks. Experts about research grants and applications at the Austrian and European levels present career opportunities and strategies to late-PhD and post-doctoral researchers.

  • The presentation language is English.
  • If you are interested in presenting your current or future work at the KLI, please contact the Scientific Director or the Executive Manager.

Event Details

Berta Verd
KLI Colloquia
Evolution of Different Dynamic Modes of Segmentation
Berta VERD (KLI)
2016-04-28 16:30 - 2016-04-28 16:30
Organized by KLI

Topic description:
Insects use two main modes of segment determination during development: the ancestral short-germband mode (eg. Gryllus bimaculatus), where new segments are added sequentially, and the long-germband mode (eg. Drosophila melanogaster) where all segments are detemined simultaneously. In dipteran insects (flies, midges and mosquitoes), where the long-germband mode of segmentation is used, the gap genes are activated by maternal gradients and cross regulate each other to form the first zygotic regulatory layer of the segmentation gene hierarchy. A precise mathematical model of the gap genes in Drosophila melanogaster was obtained from quantitative spatio-temporal expression data and used to study the dynamics of pattern formation. This approach showed that two distinct dynamical regimes govern anterior and posterior trunk patterning. Stationary domain boundaries in the anterior rely on bi-stability. In contrast, the observed anterior shifts of posterior gap gene domains can be explained as an emergent property of an underlying regulatory mechanism implementing a damped oscillator. We have identified a dual-function three-gene motif embedded in the gap gene regulatory network which is sufficient to recover both anterior and posterior dynamical regimes. Which one governs a given region depends on the gap genes involved. This motif is known as the AC/DC circuit. The dynamical repertoire of this motif consists of another interesting regime, sustained oscillations, which are not found in the gap gene system. Since molecular oscillations are characteristic of short-germband segmentation, these findings suggest that the two modes of segment determination may have more in common than previously thought, and helps us understand why long-germband segmentation may have evolved several dozen times independently from the ancestral short-germband mode.


Biographical note:
Berta Verd holds a Bachelor´s degree in Mathematics from Polytechnic University of Catalonia (UPC), Barcelona and Master´s degrees from Kings College as well as Imperial College, London. She worked on her PhD thesis at the Centre for Genomic Regulation at the Pompeu Fabra University, Barcelona and at the Wissenschaftskolleg zu Berlin. She has recently completed her PhD and is now a Postdoctoral Fellow at the KLI.