Physics Colloquium

How does a cell know how big it is?

In 1952, Alan Turing showed that diffusion coupled to chemical reactions can spontaneously generate spatial patterns whose wavelength, of order sqrt(D/k), is set by molecular parameters, the diffusion constant D and the reaction rate k. This intrinsic "ruler" was a key feature of his theory of morphogenesis. Yet many structures inside cells, famously the nucleus and the mitotic spindle, follow a different rule: their size is set by the size of the cell that contains them. A cell must therefore somehow measure its own size. I will describe mathematical models of chemical networks that accomplish this engineering feat and compare their predictions with quantitative experiments. Along the way, I hope to show that the physicist's approach works in cell biology as well as anywhere else: sharpen an idea by writing it in the language of mathematics, then test the math against quantitative measurements.

Join via Zoom: https://caltech.zoom.us/j/84497014003

Meeting ID: 844 9701 4003