It is often considered that early animals and their modern day representatives, sponges, lack polarity. This distinction is uncomfortable, because it is clear that the larva of a sponge (above) is highly polarized, and in fact polarity is necessary to coordinate swimming to a preferred site to settle. Some then say that only certain sponges (e.g. Calcarea and Homoscleromorphs) have polarity as adults. Are other adult sponges really unpolarized? What is polarity, why do animals have it, and how can we recognize it?
Pam Windsor
I am interested in the evolution of developmental genetic mechanisms that operate to pattern the early embryo, specifically the embryonic axis and certain types of polarity.
My research involves the identification of genes in sponges that are known in other metazoans to be involved in this early patterning. By understanding gene expression and function in sponges, we hope to be able to relate unconventional sponge development and body plan to those of other metazoans.
Projects I’m involved in are:
1) Embryology of a freshwater sponge, Eunapius fragilis. Analysis by SEM, TEM and antibody labeling (tubulin, b-catenin)
2) Lithium chloride and alsterpaullone treatment of a developing sponge juvenile (Ephydatia muelleri). These treatments affect the Wnt signaling pathway in other metazoans.
3) Gene identification and expression in a diversity of sponge species: Eunapius fragilis, Ephydatia muelleri (Haplosclerida; Demospongiae); and Sycon coactum (Calcaronea; Calcarea). Candidates include Wnt pathway components, T-boxes and Brachyury, Notch and Delta, Sonic hedgehog, and several mesoderm-specifying genes.