Meeting Abstract
Demosponges share eight orthologous microRNAs (miRNAs), with none in common with Bilateria. While the biological functions of these demosponge miRNAs are unknown, bilaterian miRNAs function in the regulation of cellular processes including cell cycle, differentiation, and metabolism. Here, a newly developed qPCR assay to test for differential miRNA expression during dissociation and reaggregation in Spongosorites, gemmule hatching and development in Ephydatia. During Spongosorites dissociation and reaggregation, miRNA expression exhibits a global, statistically significant decrease in expression, with no recovery of miRNA expression. In Ephydatia, overall increase in miRNA expression in gemmule-hatched Stage 4 juveniles relative gemmules is observed. Differential miRNA expression during dissociation in Spongosorites (lowered global expression, and during activation, growth, and differentiation of Ephydatia gemmules (increased global expression) is a possible indication that miRNA expression is responsive to physiological changes related to heightened cellular activity, providing an interesting direction for future research. Continuing investigation into the molecular, cellular, developmental mechanisms of Porifera provides important comparative model for understanding evolutionary dynamics of the early-branching metazoan phyla.
