Polarity: 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 (left) 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?

We are using cell and molecular techniques to approach this question in several species, but foremost in the young sponges of Ephydatia muelleri hatched from gemmules

Epithelia separate the animal from its external environment. Do sponges have a true epithelium? What is a 'true' epithelium. Using cell biology and physiology methods Emily Adams assesses the integrity of the sponge epithelium. If sponges do seal and maintain integrity, what are the molecules that allow them to do this? Are they different than those in other animals, and if so, do other animals also perhaps use the same techniques?

For recent discussion of this see: Leys, Nichols & Adams, 2009 ICB 49:167-177

Coordination in sponges:Cellular sponges inflate and contract their canals (like a sneeze) to expel wastes, gametes, and perhaps just to 'sigh'. Using Ephydatia muelleri Glen Elliott found that this stereotypical response can be triggered by particulates and by Glutamate.

Glass sponges don't sneeze they just hold their breath by arresting the flagella that pump water through the body. They do this by sending electrical signals (action potentials) throughout the animal. Gabrielle Tompkins-MacDonald studied the mechanism of this behaviour with live animals in tanks. She has then cloned inward rectifier K channels from sponges and expressed them in frog oocytes to determine their physiological characteristics, and specifically to see what they can tell us about the glass sponge action potential.