Time/date: 11am, January 26, 2009

Speaker:
Dr. Chinlin Guo
Department of Bioengineering and Applied Physics
Caltech, Pasadena, CA

Title: On the pattern formation of single epithelial cell

Abstract:
Pattern formation is one of the essential steps in morphogenesis.
Despite recent progress on in vivo studies of morphogenesis, much less
understood is how cells develop morphogenetic patterns from single to
multi-cell levels. Meanwhile, micro-fabrication technique has been used
to control cell shapes on in vitro systems, but it is not clear whether
cells can spontaneously develop different patterns and if so, what the
underlying mechanism is. Here, by tuning the strength of cell-matrix
interaction, we found that single epithelial cell spontaneously develops
and progressively changes morphological patterns from bipolar, tripolar,
quadropolar to multi-polar shapes. The pattern formation can be
explained by a simple Turing model, where filopodia/lamellipodia
formation serves as local positive feedback and actomyosin contraction
plays as global inhibitor. In addition, these patterns allow cells to
adopt different kinetic strategies for multi-cell sheet formation.
Surprisingly, the structure of the contractile machinery in single cell
resembles the actomyosin ring at cell-cell adhesion sites in multi-cell
sheets, suggesting that single epithelial cell has the intrinsic
built-in machinery that guides spontaneous 2-dimensional cell sheet
formation in 3-dimensional space.