Meeting Abstract
The red-eared slider turtle Trachemys scripta elegans is equipped with impressive physiological adaptations to survive the extreme environmental condidtions of low temperature (5°C) and anoxia (lack of oxygen) it experiences while overwintering in ice-covered waters. These conditions hold the potential to impact the composition, diversity, and abundance of the turtle gut microbial community. We characterized trends in diversity (454 pyrosequencing) of the cecal mucosal microbial community of turtles that were either maintained at 21°C in normoxia, acclimated to 5°C for 5 weeks in normoxia, or acclimated to 5°C for 5 weeks in normoxia and then exposed to 2 weeks of anoxia at 5°C. Alpha diversity was lowest for 5° C anoxic turtles. Beta diversity was shifted for each exposure group, suggesting an effect of temperature, followed by an effect of anoxia on the mucosal microbiota. At the phylum level, the bacteria identified were typical of gut microbiotas of other vertebrates, but interesting differences existed among the treatment groups. The relative abundance of Aeromonadaceae was about 11 times greater in 5°C anoxic turtles compared to 21°C and 5°C normoxic turtles. By contrast, the relative abundance of Enterobacteriaceae was about 10 times higher in 5°C normoxic turtles compared to 21°C normoxic and 5°C anoxic turtles. The results add to the knowledge base on host-gut microbe interactions and provide a perspective on how gut microbiota is altered in a vertebrate host that is exposed to environmental stressors. The results may contribute to our understanding of the importance of the gut microbiota in health and disease.
