Astyanax International Meeting for Cavefish

Athula Wikramanayake, Ph.D., is an evolutionary developmental biologist whose laboratory at the University of Miami uses embryological, molecular, genomic and phylogenetic approaches to investigate the evolution of pattern formation in metazoan embryos. A major focus of his laboratory is to investigate the molecular basis for the evolution, specification and patterning of the animal-vegetal (AV) axis. The AV axis is a cytoplasmic/cytoarchitectural polarity that is present in most animal eggs, and is specified maternally by largely unknown mechanisms. This maternally deposited developmental information is used during embryogenesis to specify the primary germ layers.

The Wikramanayake Lab uses embryos of sea urchins, which are basal deuterostomes from the phylum Echinodermata, as a model system for studies on AV axis specification and patterning. In parallel with these studies in sea urchins, the lab use's this information in a phylogenetic context to gain insight into the mechanisms that may have led to the evolution of the AV axis and the evolution of the germ layers. For these comparative studies his team uses the new genomic cnidarian model system, Nematostella vectensis.

Cnidarians are thought to be the sister group to the bilaterians, making Nematostella an excellent model system for gaining insight into the conserved developmental mechanisms shared by the last common ancestor to bilaterians and cnidarians. This phylogenetic approach has yielded important insight into the evolutionarily conserved role of the Wnt signaling pathway in early pattern formation in animal embryos. Additionally, these simple marine invertebrate embryos are proving to be excellent model systems for studying the regulation and evolution of the Wnt pathway, a pathway of considerable biomedical significance.