Organismal Systems Biology Lab
Research
Animals consist of thousands of different types of molecules. To comprehend this immense complexity, we search for fundamental design principles of molecular circuits at a multi-cellular scale. To this end, we combine theory and quantitative experiments using the nematode C. elegans.
We use live imaging of C. elegans in micro chambers to make precise measurements of its development and gene expression. By genetic perturbations we test and refine quantitative models of animal development.
We currently focus on the nutritional control of growth and aging, and on body size homeostasis.
1. Do animals find an optimal balance between growth and aging?
Environmental conditions affect the rates of growth and aging. Most famously, animals delay aging when environmental nutrients are scarce, and grow more slowly. We want to understand if this control of growth and aging increases the long term evolutionary success of a genotype, or is merely a passive consequence of a slow metabolism.
Our research builds on mathematical models of life history theory stating that animals face tradeoffs between growth and aging and need to balance their investment between these two tasks. Specifically, theory predicts that a different compromise between growth and aging is optimal in different nutritional conditions.
Using genetics, we experimentally modulate the rates of growth and aging of C. elegans to test these theoretical predictions. We ask which balance between growth and aging presents the best compromise and study the molecular mechanisms by which animals compute optimal tradeoffs in different environments.
We believe that this research will unravel functions of metabolic signalling networks that are only apparent when studied at the scale of an entire animal or even population.
Mathematical model of tradeoff between growth and aging
A mathematical model predicts that under poor nutritional conditions animals have a selective benefit by shifting their investment from promoting rapid growth to delaying aging. We are testing this model prediction experimentally.
2. How do animals reach the right size?
Genetically identical individuals never look completely the same due to the stochasticity of biological processes. We want to understand how animals prevent that small differences among individuals at birth amplify to much larger differences during the development of an animal. Specifically, we focus on the relation between heterogeneity in growth and body size of C. elegans.
In principle, two individuals that differ even only slightly in their growth rate are expected to differ increasingly in their body size during development due to the exponential nature of growth. This effect is comparable to small differences in the interest rate on a bank account that over the years amplify to large differences in savings due to the benefit of compound interest.
We study if and how animals maintain a constant body size despite heterogeneity in their growth rate. To address this question, we use micro chambers to grow hundreds of individuals of C. elegans in parallel (see movie here) and track each individual's rates of growth, development and size.
Individuals of C. elegans growing in arrayed of micro chambers.
Team
The Towbin lab will open its doors officially in November 2019.
Benjamin Towbin
Principal investigator
Benjamin carried out a PhD in Genetics using C. elegans, followed by postdoctoral research in quantitative Systems Biology using bacteria. In his new lab he combines these two and applies quantitative approaches at a multi-cellular scale using C. elegans.
Optimal Growth control
2018, Cell reports
Yael Korem Kohanim, Dikla Levi, Ghil Jona, Benjamin D Towbin, Anat Bren, Uri Alon
2017, Worm
Janna Hastings, [..], Benjamin Towbin, [..], Olivia Casanueva
2017, Nature Communications
Benjamin D Towbin, Yael Korem, Anat Bren, Shany Doron, Rotem Sorek, Uri Alon
2016, Scientific reports
Anat Bren, Junyoung O Park, Benjamin D Towbin, Erez Dekel, Joshua D Rabinowitz, Uri Alon
Epigenetics and Chromatin
2015, Cell
Adriana Gonzalez-Sandoval, Benjamin D Towbin, Veronique Kalck, Daphne S Cabianca, Dimos Gaidatzis, Michael H Hauer, Liqing Geng, Li Wang, Teddy Yang, Xinghao Wang, Kehao Zhao, Susan M Gasser
2012, Cell
Benjamin D Towbin, Cristina González-Aguilera, Ragna Sack, Dimos Gaidatzis, Véronique Kalck, Peter Meister, Peter Askjaer, Susan M Gasser
2009, Current Opinions in Genetics & Development
Benjamin D Towbin, Peter Meister, Susan M Gasser
Join us!
We currently have no funded positions open, but we are always interested in motivated talent and can explore possible projects and funding opportunities, including postdoctoral fellowships from EMBO, MSCA, HFSP, or FEBS. Please get in touch by email providing your CV, a motivation letter, and a statement of research interests.
Undergraduates looking for training opportunities: Please get in touch by email!
Worm cinema
Individuals of C. elegans growing in micro chambers
Individual animals of C. elegans were recorded simultaneously in arrayed micro chambers from birth to adulthood at a time resolution of 10 minutes.
40 hours of development in 20 seconds
An individual of C. elegans expressing GFP in all cells was imaged every 10 minutes in a micro chamber for 40 hours. Images were computationally straightened and aligned. The darker area in the center corresponds to the germline.
Get in Touch
Prof. Benjamin Towbin
Institute of Cell Biology
Baltzerstrasse 4
CH-3012 Bern
Switzerland