Guillaume Witz

I have spent most of my life on the shores of the Lac Léman in western Switzerland around the wine region of Lavaux. After classical latin-greek studies at high-school there, I took a sharp turn and obtained a Master in Physics from the Ecole Polytechnique Fédérale de Lausanne (EPFL). I then took yet another (smoother) turn towards biology by embarking on a Ph.D. in biophysics in the lab of Prof. Giovanni Dietler, still at EPFL, and in collaboration with Dr. Andrzej Stasiak at Lausanne University. Using atomic force microscopy and numerical simulations, I studied the effect of various topologies (knotting, catenation, supercoiling) on the bio- and polymer physics behavior of small circular DNA molecules.

To complete my turn in the direction of biology, I then moved to the USA to spend four years mostly as an SNF post-doc in the lab of Prof. Nancy Kleckner at Harvard University. There I learned the essential techniques of microbiology and fluorescence microscopy in order to study the structure and dynamics of a much larger DNA molecule, the E.coli chromosome (or nucleoid). Using 3D time-lapse microscopy and image processing software that I developed, I explored the connection between small scale events such as initiation of DNA replication and the larger nucleoid behavior.

While exploring that topic, I discovered that the essential question of how bacteria, and specifically E.coli, manage to coordinate their DNA replication cycle and their cellular division cycle remains unanswered. I obtained an SNF Ambizione Fellowship to study that question and joined the van Nimwegen lab at the Biozentrum of Basel University at the end of 2015. I plan to combine the labs’ expertise in controlled bacterial growth in microfluidics devices as well as its focus on regulatory mechanisms with my experience in microbiology and image processing in order to explore that open question.

While I’m coding at my computer or pipetting at my bench my passion for classical music follows me, but of course I prefer live concerts. To have a more personal connection to music I also (try to) play the harpsichord.