Evolutionary developmental biology is an interdisciplinary field that merges developmental genetics with evolutionary biology to address questions concerning how changes at molecular level lead to morphological diversity. This course is designed to teach the general principles for students who are interested in this field. In addition, we will development innovative hands-on activities to allow students gain practical experiences. The main topic for this course is gastrulation.
Gastrulation is the first morphogenetic event of the developing animal embryo. In the metazoan embryo, the three germ layers – ectoderm, mesoderm and endoderm – are specified during gastrulation, as they undergo a distinct series of morphogenetic movements to differentiate and form lineage-specific tissue and organ structures. Drosophila melanogaster, one of the best known genetic model organisms, has been serving as a preeminent platform for the study of gastrulation morphogenesis. Not only have the studies in this species established a wealth of knowledge concerning cell fate patterning and tissue mechanics during gastrulation, they have also invited comparative studies using other insect species. Strikingly, gastrulation morphogenetic movements have been shown to substantially diverge within the lineage of Diptera, to which Drosophila belongs, raising the question of whether the divergences occurred incrementally or abruptly during the course of evolution. To address this question, we have conceived a research program that aims at a comparative analysis of gastrulation movement among the closely related Drosophila species. This program will seek a detailed sampling of representative species in the phylogenetic void between Drosophila melanogaster and the scuttle fly Megaselia abdita, the closest relative whose gastrulation has been previously examined. It will aim at identifying the conserved and diverged components of gastrulation morphogenesis within this phylogenetic spectrum and yielding a first look at the phylogenetic profile of gastrulation morphogenesis at the evolutionary timescale.