Research

During morphogenesis of multicellular organisms, cells assemble into tissues that are extensively remodeled to yield the characteristic size and shape of organs. Our Developmental Morphogenesis lab studies the patterned cell activities and the underlying physico-chemical mechanisms that orchestrate the emergence of biological form. We have introduced two genetically and optically tractable arthropod species, the shrimp-like crustacean Parhyale hawaiensis and the beetle Tribolium castaneum, as powerful and attractive model systems to study the molecular, cellular and mechanical basis of tissue and organ morphogenesis during animal development and evolution.

While the information about organismal form is encoded in the genome, the sculpting of living structures in 3D space over time is ultimately a physical process. We continue to develop functional genetic and imaging tools to meet the challenges of capturing and measuring the behaviors of thousands of cells, subcellular structures and gene expression dynamics in the normal context of Parhyale and Tribolium development. In addition to more traditional imaging methods, such as widefield and confocal microscopy, we have embraced multi-view light-sheet microscopy to image fluorescently labeled specimens in their entirety, over long periods of time, at high spatial and temporal resolution, and with minimal photo-bleaching and photo-toxicity. We use these multidisciplinary approaches to study the allometric growth of serially homologous limbs, the conservation and divergence in limb patterning mechanisms, and tissue mechanics driving early insect embryogenesis.

So far, quantification of cell behaviors in imaged wild-type or genetically and mechanically perturbed embryos has offered a bottom-up perspective of various morphogenetic processes in Parhyale and Tribolium. In the case of Parhyale, comprehensive reconstructions of fate maps using new open-source software available as a Fiji/ImageJ plugin has provided insights into the cell lineage restrictions and differential cell behaviors contributing to animal limb bud formation and outgrowth. In the case of Tribolium, combining imaging of nuclear, membrane, cytoskeletal actin and myosin dynamics with physical modeling has provided insights into the cell and tissue interactions and the forces contributing to widely conserved epithelial movements during animal gastrulation. Comparisons between Parhyale, Tribolium and other classic model systems in developmental biology, like flies, fish and the mouse, have started shedding light on the conservation and divergence of morphogenetic mechanisms by which animal tissues take shape during development.