Lucas Ribaudo, advised by Professor Andrew Mugler, presented his research, “A general mechanism for cell size control in yeast,” at the Emil Sanielevici Research Award Seminar on February 12, 2025. This scholarship is awarded annually to an undergraduate major in the Department of Physics and Astronomy in memory of our student, Emil Sanielevici (1979-2000), whose enthusiasm and love of scientific research continue to inspire us all. Each year, the winner of the award will present their research at this seminar.

Watch Lucas' presentation of his research here. 

A general mechanism for cell size control in yeast

Size is a key physiological variable for cell growth. Subjected to noise, cells must employ active size control. However, the mechanistic origins of size control remain elusive. One possibility is that cells have molecular thresholds for key molecules that must be reached for division to commence. Eukaryotic cells (e.g., fission yeast) are believed to reach a concentration-based threshold. Additionally, it has been found that yeast cells follow a “sizer” control mechanism, targeting a specific size before division, but the origins of this control strategy remain unclear. Here, we introduce a generic model that relies on multiple concentration checkpoints for different cell components. Our results show that if at least one checkpoint relies on a molecule whose concentration is proportional to volume, then sizer control dominates the control strategy. We show that this model is consistent with experimental data and suggests that size control is separate from division control in yeast.

Congratulations Lucas! And thank you to Sergiu Sanielevici for continuing to join us in preserving Emil's memory through this award.

Apply for the 2025-26 Award! Applications are due on March 10, 2025.