Meeting Abstract
Without tissues or organs dedicated to osmoregulation, cnidarians, such as the sea anemone Nematostella vectensis, cope with environmental salinity stress on a cellular level. To explore the means by which N. vectensis is able to tolerate a wide haline window, we sought to describe aquaporin (AQP) water channel transcription and protein function in transport. Using quantitative PCR we found that a subset of identified AQPs are up- and downregulated in response to salinity fluctuations that occur in their natural estuarine habitats. The pattern of expression for these genes varied when comparing over development, suggesting differential regulation for particular stages. In order to test for transport function of AQP proteins, we performed heterologous expression of anemone AQPs in the Xenopus laevis oocyte system. We demonstrate that select AQPs from N. vectensis transport water, as well as other cellular metabolites, reflecting their phylogenetic relationship with other AQP proteins from vertebrate species. Our data suggest that the aquaporin gene family underwent an independent radiation in cnidarians that is mirrored in the transcriptional dynamics and transport functions in osmotic response.
