Abstract

Chemotaxis allows cells to sense and migrate towards chemicals, and is fundamental to single-cell organisms, our immune response, cancer metastasis, learning and development. Interestingly, the process is remarkably accurate, allowing cells to chemotax in extremely shallow concentration gradients, corresponding to a difference of only a few ligand-bound receptors across cell length. What is the fundamental physical limit of detection for cells, and how can cells reach this limit? In this talk, I will present recent results on quantitatively describing data of Dictyostelium amoeba in a microfluidic chamber with highly controlled chemical gradients. Specifically, I will demonstrate that the chemotactic index, a measure of the accuracy of chemotaxis, is just a function of the signal-to-noise ratio (SNR) of cell sensing, not the chemical gradient steepness or the average chemical concentration. Furthermore, mathematical analysis shows that cell shape and behaviour, although highly variable, are a function of the SNR . This links cell shape and behaviour with the cell’s strategy to reach the physical limit of detection.

http://www3.imperial.ac.uk/people/r.endres