Meeting Abstract
The temperate aggregating anemone Anthopleura elegantissima occurs in the symbiotic state while developing and residing in direct light exposure and the aposymbiotic state on the undersides of rock benches that consistently block light. Present in diverse intertidal and sub-tidal environments, it is adapted to relatively cool water temperatures in light deprived regions and to endure desiccating environments characterized by large temperature variability. Cnidarians, corals and anemones, possessing symbionts may undergo more extreme environmental changes than their aposymbiotic counterparts. Facultative symbiosis allows A. elegantissima to act as a model system for analyzing the physiology, ecology, and molecular biology of temperate cnidarian-dinoflagellate symbioses. To further understand the interactions between symbiosis and environment in temperate cnidarians, symbiotic and aposymbiotic A. elegantissima were subjected to light and temperature variations and sampled over several days to examine the mitotic index and relative gene expression between symbiotic states. Haemocytometer counts were used to calculate the mitotic index, percentage of dividing symbionts. Relative gene expression was determined by qPCR analysis. Two of the analyzed genes are associated with the vitamin K cycle: sym32, which is related to symbiosis and encodes a fasciclin domain protein and calumenin, an inhibitory protein. HSP90 and ferritin genes were analyzed for heat stress effects. The consequent mitotic indices and relative gene expressions demonstrate an involved story of symbiosis in relation to light and temperature in A. elegantissima.
