Ephydatia muelleri is a green or yellow sponge that is found in lakes and rivers throughout the northern hemisphere. We chose to sequence its genome because - among freshwater sponges - it has a couple of characteristics that are very practical. First it has been studied in Japan, Europe, and North America, for several decades. Its gemmules are robust and tolerate freezing to -80C meaning we can ship them across continents for others to work on. It can be easily cultured in the lab and each gemmule is a clone of the adult sponge, meaning thousands of clones can be cultured from the same genotype.
And...it sneezes! What could be more cool than a sponge with no nervous system 'sneezing'? The sneeze can be triggered in the lab and so this behaviour is a very tractable system to study.
What is the evolutionary history of sensory cells in metazoans?
This project aims to understand the physiology, cytology and molecular biology of cells that receive information from the environment and transmit it to an effector. We are studying larval sponges as well as juvenile and adult sponges. This work involves video imaging of adult animals in their native habitat, lab work with larval cultures (also at field stations), molecular work to study genes expressed in particular tissues, and ultrastructure to understand the tissues and cell connections that underlie these behaviours.
What were the first animals like? What were early oceans like for light, phytoplankton, bacteria, oxygen? What did the first animals eat?
We have a rich set of fossils from the Burgess Shale which should reveal the lifestyle of the early Cambrian filter feeding fauna. By understanding the ecology of that fauna and other fossil sponge and ctenophore fauna we will have a better grasp of what was possible in those seas.
Vauxia (left) is a cool sponge that lived in what is now the Burgess Shale British Columbia. [See Pablo Aragones' project description]
Glass sponges are stunning pillars of golden animals. They are silent in filtering thousands of liters of water - removing bacteria and other pico-plankton - for food, and excreting the wastes as CO2, ammonium, and particulates for others to use. They are a hugely important factor in recycling water, especially where large numbers exist. On the west coast of British Columbia glass sponges form vast reefs, some under the flight path into the Vancouver Airport. Why do reefs form where they do, why glass sponges live only in deep, cold, silica rich water?
[See Nikita Sergeenko's project description]