Description:

Richard Carthew is Director Emeritus of NITMB and a Professor in the Department of Molecular Biosciences at Northwestern University. 

Title:  Emergence of a hexagonal lattice of photoreceptor neurons by tissue-scale mechanics

Abstract:

Animal development is marked by a progressive emergence of ordered structures from disordered precursors. Various models are used to describe such developmental phenomena, and a long-standing model has been the Reaction-Diffusion Model. One such RD model nicely describes the emergence of a hexagonal lattice of photoreceptor neurons in the developing eye of the fruit fly Drosophila. The model relies on activator-inhibitor pairs that are essential for the patterning in vivo. Nevertheless, the RD model has not been tested by real-time observation of the developmental dynamics. We did so using live-imaging microscopy and discovered a completely unexpected mechanical component in eye development. Ordered periodic flows of cells within the eye epithelium create the hexagonal lattice from a pseudo-square lattice prepattern of greater disorder. Thus, an RD mechanism, if involved, is likely generating the prepattern, which then evolves by a mechanical mechanism into the mature hexagonal lattice of the compound eye.

Research Summary: Free-living cells navigate a challenging world using solitary solutions. In contrast, cells within a multicellular organism must act as a collective to carry out functions for the benefit of all. We study the unique and complex biology of cells in the context of tissues and organs. Model organisms such as the fruit fly Drosophila provide an unprecedented opportunity to understand the cell biology of multicellularity. Our lab uses a variety of high-throughput experimental tools such as genomics, genetics and quantitative imaging. We couple such data-intensive experiments with computational analysis and modeling. The goal is to gain a comprehensive and predictive understanding of how multicellular properties emerge from the collective of cells present in a tissue or organ. Such understanding has implications for diseases such as cancer, as well as methods of tissue regeneration to treat disease.

The NSF-Simons National Institute for Theory and Mathematics in Biology Seminar Series aims to bring together a mix of mathematicians and biologists to foster discussion and collaboration between the two fields. The seminar series will take place on Fridays from 10am - 11am at the NITMB in the John Hancock Center in downtown Chicago. There will be both an in-person and virtual component.

More information: https://www.nitmb.org/nitmb-seminar-series