Emergence of the cytokinetic Rho zone that orchestrates formation and ingression of the cleavage furrow had been explained previously via microtubule-dependent cortical concentration of Ect2, a guanine nucleotide exchange factor for Rho. Recently we found that, en route from resting cortex to fully established furrow, there lies a regime of cortical excitability in which Rho activity and F-actin play the roles of the prototypical activator and inhibitor, respectively. This cortical excitability is manifest as dramatic traveling waves on the cortex of oocytes and embryos of frogs and starfish. We propose that cortical excitability explains the ability of cytokinetic furrow to rapidly follow the position of the cell division spindle.
Andrew Goryachev is a computational cell biologist specializing in mathematical modelling of biological systems. Trained as a biophysicist, he received his Ph.D. for studies of self-organization and pattern-formation in complex chemical systems. After establishing his own research group in 2003, Andrew began to develop a unique research program in understanding the role of small GTPases, monomeric G-proteins considered “molecular switches”, in intracellular morphogenesis and pattern-formation. His whole-cell model of yeast bud emergence proposed a novel biophysical paradigm to explain the pattern-forming role of the Rho-family GTPase Cdc42. Andrew established a number of successful collaborations with cell and developmental biologists worldwide with whom he works on the elucidating the role of small Rho GTPases in the fundamental processes of cellular morphogenesis, such as establishment of cell polarity, formation of cytokinetic furrow and asymmetric cell division. Currently he is a Reader at the School of Biological Sciences, University of Edinburgh.