VUB research: Physics also plays an important role in the origin of life
During her PhD at the Vrije Universiteit Brussel and the Université Libre de Bruxelles, Rossana Bettoni investigated how cells in an embryo know exactly what they should become. Her work highlights a surprising element: the shape and position of a cell are at least as important as the chemical signals it receives.
“When an embryo develops, cells must specialize – some become skin, others the brain. But how do those cells know what to do? That’s what I looked into,” Bettoni explains. She studied these processes in a small sea creature, the ascidian, which is often used in biological research because it has a simple yet predictable embryo.
One of the striking discoveries in her research is that the way cells touch each other influences what they become. It’s not only about which signal they receive, but also about how large the contact surface is with the cells sending that signal. “We discovered that cells don’t just listen to the strength of the signal, but also to how they are positioned and make contact with their neighbors,” she says. “Their geometry, how they fit together, turns out to be essential.”
At the core of her research was the so-called ERK pathway, a signaling route that determines whether a cell develops into a nerve cell. But remarkably: even when cells received the same amount of signal, this did not always lead to the same outcome.
“What we saw is that only a few cells respond by activating a gene called Otx – a sign that they will develop into neural cells,” Bettoni says. “And that difference could be explained with mathematical models that take into account the shape of the embryo.”
The dissertation combines biological experiments with mathematical models. These models showed that cells with a larger contact surface with ‘signaling’ neighbors were more likely to respond – even when the chemical signals were the same. “Even with a single source of signaling, the shape of the cell can change everything,” says Bettoni. “A small shift in how a cell is positioned can determine whether it acquires neural identity or not.”
Her findings have been published in international journals such as Developmental Cell, PLoS Computational Biology and PRX-Life. In May 2024, Bettoni presented her work at the renowned symposium Physics of cell fate decisions in Vienna (ISTA). This year she also presented her research at the prestigious European Molecular Biology Laboratory (EMBL) with a poster presentation.
Dr. Bettoni’s research demonstrates the precision of the interplay between biology and physics in the emergence of life. It also opens new doors for applications, such as tissue engineering or guiding cell growth in medical technology.
“What fascinates me is that a cell – without consciousness – still knows exactly what to do, simply because of its position in the whole,” Bettoni concludes. “It’s a beautiful example of how the laws of nature at the microscale govern our greatest biological processes.”
About the researcher
Dr. Bettoni obtained her PhD at the Faculty of Sciences and Bioengineering of the VUB, in collaboration with ULB. She conducted her research under the supervision of Professor Sophie de Buyl in the Data Analytics Lab. Her work has been recognized through open-access publications and presentations at international conferences.
More info
Rossana Bettoni: rossana.bettoni@vib.be
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