Shifting metabolic priorities among key protistan taxa within and below the euphotic zone

Dataset for submitted publication: Sarah K. Hu, Zhenfeng Liu, Harriet Alexander, Victoria Campbell, Paige Connell, Karla B. Heidelberg, Sonya Dyhrman, & David A. Caron. Shifting metabolic priorities among key protistan taxonomic groups within and below the euphotic zone. In press. Environmental Microbiology. https://doi.org/10.1111/1462-2920.14259 See associated GitHub repository: https://github.com/shu251/SPOT_metatranscriptome Abstract A metatranscriptome study targeting the protistan community was conducted off the coast of Southern California, at the San Pedro Ocean Time-series station at the surface, 150 m (oxycline), and 890 m to link putative metabolic patterns to distinct protistan lineages. Comparison of relative transcript abundances revealed depth-related shifts in the nutritional modes of key taxonomic groups. Eukaryotic gene expression in the sunlit surface environment was dominated by phototrophs, such as diatoms and chlorophytes, and high abundances of transcripts associated with synthesis pathways (e.g. photosynthesis, carbon fixation, fatty acid synthesis). Sub-euphotic depths (150 m and 890 m) exhibited strong contributions from dinoflagellates and ciliates, and were characterized by transcripts relating to digestion or intracellular nutrient recycling (e.g. breakdown of fatty acids and V-type ATPases). These transcriptional patterns underlie the distinct nutritional modes of ecologically important protistan lineages that drive marine food webs, and provide a framework to investigate trophic dynamics across diverse protistan communities. Most recent version - March 16, 201