Student Research - Biology

Lisa Warner

Sponges as an evolutionary model

Abstract: The sponge has many characteristics associated with complex species, however, they lack a nervous system, sensory organs, and a defined body axis. The sponge occupies a unique phylogenetic position, which makes this them an ideal model for studying the evolutionary development of sensory systems. We have isolated a Six1/2 gene from sponge. Since more complex animals possess multiple Six gene family members, our data supports the hypothesis that Six1/2 was the ancestral gene that later became involved in the eye pathway. We also have demonstrated that Six1/2 is expressed throughout larval development and in adult tissue, during cellular aggregation and as well as during differentiation. Additionally, the Six1/2 gene is expressed in the atrial pinacoderm and regions surrounding choanocyte chambers. Choanoctye chambers permit sponges to respond to external stimuli and be acting as a primitive "sensory system."

Click here to view Lisa's paper on Shigella, published in Infection and Immunity.