Eternal sunshine of the spotless cycle?
In a recent study, Purvis and colleagues (Chao et al, 2019) quantify cell cycle phase durations in human cells and propose a model whereby cell cycle progression in single cells is a succession of uncoupled, memoryless phases, each composed of a characteristic rate and number of steps. They also suggest that having such memoryless phases is a feature of healthy cells, while cancer cells have correlated phases. Silvia Santos (Crick, London) and Lendert have written a News&Views piece about this article.
Do biological timers and sensors work together to coordinate processes in cell signaling?
In a perspective piece in BioEssays, Junbin Qian, Mathieu Bollen, and Lendert argue that this is indeed the case. Recent data suggest that timers and sensors can work together to guarantee correct timing and responsiveness. By exploring examples of cellular stress signaling from mitosis, DNA damage, and hypoxia, we discuss the common architecture of timer‐sensor integration, and how its added features contribute to the generation of desired signaling profiles when dealing with stresses of variable duration and strength.
Pedro reports on how quadratic soliton combs are formed in Optics Letters
In a joint effort with Tobias Hansson, Stefan Wabnitz, and François Leo, Pedro investigated theoretically the dynamics of quadratic frequency combs in a dispersive second-harmonic generation cavity system. We identified different dynamical regimes and demonstrated that the same system can exhibit both bright and dark localized cavity solitons in the absence of a temporal walk-off. These results are published in two Optics Letters papers, see here and here.
Stefan’s joint work with the Raes and De Vuyst lab has been published in eLife
In a collaboration with the lab of Jeroen Raes (KUL) and Luc De Vuyst (VUB), Stefan has helped exploring human gut community dynamics. We established a synthetic community composed of three representative human gut isolates (Roseburia intestinalis L1-82, Faecalibacterium prausnitzii A2-165 and Blautia hydrogenotrophica S5a33) and explored their interactions under well-controlled conditions in vitro. Using a mechanistic model as reference, we demonstrated that strains grown in co-culture behaved differently than those in mono-culture and confirmed their altered behavior at the transcriptional level. For more information, see the publication in eLife.
We're happy to welcome Arno to our lab! Arno studied biosystems engineering and he will be designing and using microfluidic devices to study various aspects of the spatiotemporal regulation of the cell cycle.
Stefan and Alexandra show how excitability can lie at the heart of toxin excitations in bacteria
Toxin-antitoxin (TA) systems in bacteria and archaea are small genetic elements consisting of the genes coding for an intracellular toxin and an antitoxin that can neutralize this toxin. In various cases, the toxins cleave the mRNA. Stefan and Alexandra have used deterministic and stochastic modeling to explain how toxin-induced cleavage of mRNA in TA systems can lead to excitability, allowing large transient spikes in toxin levels to be triggered. This work has been published in PLoS One .
Stefan publishes work on the dynamics of two interacting microbial species in the chemostat
In the context of Stefan’s joint PhD at the ULB (with D. Gonze) and VUB (with J. Danckaert) in Brussels, he has theoretically studied the dynamics of two interacting microbial species in the chemostat. These species are competitors for a common resource, as well as mutualists due to cross-feeding. He demonstrated that this system has a rich repertoire of dynamical behavior, including bistability, and showed that the different steady state solutions can be well captured by an extended Lotka-Volterra model. This work was published in PLoS One.
Pedro publishes detailed bifurcation study of localized light pulses in optical resonators
Pedro has studied the origin, stability, and bifurcation structure of different types of bright localized structures described by the Lugiato-Lefever equation. This mean field model describes the nonlinear dynamics of light circulating in fiber cavities and microresonators. In this work, published in Phys. Rev. E , we show how the organization (bifurcation structure) of these localized light patterns critically changes as one increases the cavity detuning, one of the important experimental control parameters in the system.
Commentary on the function of dynamic phosphorylation-dephosphorylation cycles published in Dev. Cell
Adrian Saurin (Dundee Univ.) and Lendert have written a commentary on the potential roles of dynamic phosphorylation-dephosphorylation cycles. They discuss how rapid cycles could underlie important signaling properties, including the ability to rapidly bind and release proteins.
Work on delay models for the embryonic cell cycle published in PLoS One
Jan's work on delay models for the early embryonic cell cycle oscillator has been published in PLoS One . We showed that different implementations of the time delay can have a large impact on the resulting oscillation, exploring a fixed time delay, a distribution of time delays, and a delay that is state-dependent. Well done Jan and Alexandra!