Author: mpolin

Myosin tracking with iSCAT and a Galaxy-recognition Python library

myosin_recognition

We recently had the great opportunity to collaborate with Darius Koester to study the behaviour of myosin II bundles and actin filaments. Our side of the work was spearheaded by Lewis Mosby, who adapted a Python library originally used to feature galaxies to recognise the myosin bundles, and analysed in great detail their motile behaviour. Part of this work is published in The Biophysical Journal  (preprint here). The detailed description of the myosin tracking can be found in a Special Issue of The Journal of Physics D, from the IOP (preprint here).

Confinement “diversifies” micro-swimmers

confined_flow

From soil bacteria to sperm swimming in the fallopian tubes, microorganisms are often found to swim within confined environments. What is the effect of confinement on their flow fields? In a new paper, recently published in Physical Review Letters, we combine experiment and modelling to show that -contrary to expectations- the variety of microbial flow fields is greatly increased under confinement. This can in turn have have qualitative effects on both the biology (e.g., feeding currents) and the physics (e.g., collective behaviour) of microorganisms in confinement. This work was done in collaboration with Raphael Jeanneret and Mitya Pushkin.

 

Dr. Henshaw!

Great news! On Friday Richard has successfully defended his PhD thesis 🙂 We were all very happy and wish Richard all the best in his future postdoc at Tufts! A couple of papers from his thesis work on micromonas will be submitted later this year 🙂

PhD and PDRA opening for biophysics of phototaxis

Leverhulme_Trust_CMYK_black

Currently seeking a PhD student  (UK/EU) and a PDRA (any nationality) to work on an exciting new international and interdisciplinary project exploring the link between light-induced motility and photosynthesis in microalgae.

The project is generously funded by The Leverhulme Trust, and is a collaboration with Idan Tuval (IMEDEA, Mallorca Spain) and Dimitris Petroutsos (CEA, Grenoble France). It will involve extensive travelling between the partners (all costs covered)!

Apply here or here for the PhD, and here for the PDRA. Starting date Sept 2019 (potentially flexibility). Project duration 3.5y.

For more informations, feel free to contact Marco.

In Phase or Out of Phase, that is the question

 

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How do cilia synchronise? Through hydrodynamics? Elasticity? Intracellular coupling? The mechanism seems to depend on whether these oscillators belong to same cell or not. In the latter case, we have shown that hydrodynamic interactions suffice; in the former, however, direct intracellular coupling between the flagella is necessary (see here, here, and here). How is this coupling acting? How can it promote opposite types of synchronisation? Our idea is that synchronisation states depend on the cell actively stiffening/relaxing the internal fibres joining the ciliary basal bodies. We explore this hypothesis in our new paper, recently accepted in J. Roy. Soc. Interface, looking at a  minimal model of “cilia coupled by intracellular connections”. (ArXiv preprint. Full version and Supplementary Informations including animations). A big Thank to U. Melbourne and its Department of Mathematics and Statistics for hosting Marco during the final developments of this work!!

Fluids CDT Summer School @ Imperial

Last week I gave a couple of lectures at the Fluids CDT Summer School, organised by Eric Keaveny and Chiu Fan Lee. It was great fun (for me, at least), and I would have liked to be able to stay more than just one day… In any event, if you’re interested, you can find a PDF of my presentation on bacterial and eukaryotic motility (…as in swimming) here and here. Enjoy! …and please let me know your thoughts/comments!