Meeting Abstract
All animals must coordinate multiple different cell types in response to environmental stimuli. Rapid responses to environmental stimuli in eumetazoans are performed by the nervous and neuroendocrine systems. However, poriferans lack nerves and so must use other coordination mechanisms. The demosponge Ephydatia muelleri uses the local secretion of a variety of small molecules to coordinate responses of tissues. One major response coordinated by small molecules is the inflation-contraction response to rid the sponge of irritants that may interfere with water filtration. A previous study found that glutamate triggers contractions that propagate throughout the body of E. muelleri. The same study detected D-aspartate within E. muelleri. In eumetazoans D-aspartate is known as a neurotransmitter and modulator of reproductive functions, but its signaling role within E. muelleri is currently unknown. We hypothesize that D-aspartate is used, like glutamate, to propagate the inflation-contraction response along tissues in E. muelleri. We will first examine E. muelleri transcriptome data to verify if the sponge produces transcripts for enzymes necessary in the biosynthesis of D-aspartate. Then we will determine the effect of the application of exogenous D-aspartate on E. muelleri individuals in which inflation-contraction is induced. Finally, in-silico analyses on E. muelleri enzymes involved in the synthesis or degradation of D-aspartate will be used to select compounds that are most likely to inhibit these enzymes. The effect of these compounds on E. muelleri inflation-contraction will then be evaluated. This study will provide insights into the signaling toolkits used by sponges to respond to the selective pressure of avoiding clogging the filter.
