University of California, Los Angeles
621 Charles E. Young Dr. South
Los Angeles CA 90095-1606
Phone: 310 206-7885
Photo © Winston Macdonald 2014
In our effort to examine the evolution of metazoan complexity, we have focused on the development of sensory structures in scyphozoan cnidarians. These jellyfish have eyes, statocysts, and complex neural organization, as well as a relatively comprehensive suite of developmental molecules, which function in sensory, neural and cephalic development in Bilateria. We also have complementary work in progress on polychaete and acoel flatworm neural and sensory organization, and incipient work on sponges. Thus we are characterizing the similarities in neural and sensory development and cell-type differentiation across the basal Metazoa to better understand the evolution of animal complexity, with particular regard to neural organization.
To date our work on jellyfish involves examination of neural and sensory development and developmental genetics in all three developmental stages: planula, polyp and medusa. In this effort we are using a range of techniques. We employ: TEM to assess ultrastructural details of cell types and neural anatomy; Confocal microscopy to mark and visualize structural components of sensory cells, nerves, and muscles (small neuropeptides, tubulins, and actin, respectively); and additional markers to track cell division (BrdU) and cell death (caspase). In combination these permit a three-dimensional understanding of morphology and developmental process. We then determine the locus of gene expression, using in situ hybridization, of developmental genes know to be involved in the differentiation of sense organs and sensory cell types in bilaterians. These results are also visualized using confocal microscopy, in combination with other markers so that the detailed tissue and cellular context of gene expression can be determined.