SymbNET Online Seminar Series – Jordi Van Gestel (UCSF) & Jonathan Howard (FCG-IGC)

Dear all,

On 17th March (Thursday), we will have the next session of the SymbNET Seminar Series:

15:00 WET / 16:00 CET

Jordi Van Gestel
University California, San Francisco (UCSF)
Postdoctoral Scholar, Microbiology and Immunology at School of Medicin

Short-range quorum sensing controls horizontal gene transfer at micron scale in bacterial communities.
In bacterial communities, cells often communicate by the release and detection of small diffusible molecules, a process termed quorum-sensing. Signal molecules are thought to broadly diffuse in space; however, they often regulate traits such as conjugative transfer that strictly depend on the local community composition. This raises the question how nearby cells within the community can be detected. Here, we compare the range of communication of different quorum-sensing systems. While some systems support long-range communication, we show that others support a form of highly localized communication. In these systems, signal molecules propagate no more than a few microns away from signaling cells, due to the irreversible uptake of the signal molecules from the environment. This enables cells to accurately detect micron scale changes in the community composition. Several mobile genetic elements, including conjugative elements and phages, employ short-range communication to assess the fraction of susceptible host cells in their vicinity and adaptively trigger horizontal gene transfer in response. Our results underscore the complex spatial biology of bacteria, which can communicate and interact at widely different spatial scales.

15:30 WET / 16:30 CET

Jonathan Howard
Instituto Gulbenkian de Ciência (IGC-FCG)
Host-Pathogen Co-evolution

The maintenance of avirulence in Toxoplasma gondii.
The transmission of T. gondii is dependent on avirulence, guaranteeing lifelong parasitism. The selective cost of infection to the host is not balanced by any competing advantage; the optimum strategy for the host is to defeat the parasite. Thus the avirulent state has to defend itself against the Scylla of rapid elimination by host immunity and the Charybdis of virulence resulting in acute death of the host. I will discuss a novel aspect of this phenomenon, in which host and parasite conspire to limit the intensity of the initial immune attack, allowing the parasite to escape and encyst in the brain.

These will be monthly online seminars on host-microbe symbiosis, genomics, and metabolomics, with two talks from SymbNET researchers.

Slots of 30 minutes to talk with the speakers will be available after the seminars. Priority will be given to students and Postdocs from SymbNET members Institutions. If you are interested, please contact Mariana Simões at

These seminars are open and free of charge. You can find more information at

If you already registered for SymbNET activities before, you will receive a link to this seminar closer to the date. If not, please register at

We are looking forward to your participation.

SymbNET – Genomics and Metabolomics in a Host-Microbe Symbiosis Network

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 952537


Jordi Van Gestel (UCSF) & Jonathan Howard (FCG-IGC)


March 17th, 2022


Zoom Meeting

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