In this talk, I’ll discuss two recent lines of research in my group, related by the common element of being a multiscale problem of spatial organization.
(1) For over a century, the development and replacement of reptile teeth has been of interest in comparative anatomy and evolutionary biology due to the prevalence of teeth in the fossil record and, more recently, for understanding spatiotemporal patterning in developmental biology as well as the fundamentals of tooth replacement for a clinical context. In collaboration with the Richman Lab (UBC Dentistry), we are using the Leopard Gecko as a model organism to understand the mechanisms underlying the regular and long-lasting spatiotemporal patterns of tooth replacement seen in many polyphyodonts. I will describe the data and our implementation and analysis of several mechanisms that have been proposed in the past to explain the observations. Finding shortcomings in these models, we propose a new model, the Phase Inhibition Model, a coupled phase oscillator model, which does better at explaining the data.
(2) Many externally bilaterally-symmetric animals, including both vertebrates and invertebrates, have an internal left-right asymmetry that is established during embryo development. This asymmetry can be critical for proper organ function (e.g. the mammalian heart). In C. elegans, left-right asymmetry (chirality) arises during cell division at the four-cell stage and eventually manifests in a consistent handedness in the twisting of intestine and gonad in the adult. In collaboration with the Sugioka Lab (UBC Zoology), we are developing models to explain the onset of chirality. Chirality appears intracellularly during cell division in the form of chiral flow of the actomysosin cortex. We hypothesize that this flow induces friction forces between neighbouring cells mediated by adhesions. The model takes the form of force balance differential equations and does well in comparison with quantitative data extracted from live-cell and in vitro imaging.