Transcriptomic Analysis of Grazing by Marine Nanoflagellates

Synechococcus is an important contributor to coastal and open ocean primary productivity. It is thought to be consumed by heterotrophic nanoflagellates and ciliates. To better understand if such predators adapt to the consumption of different prey, we obtained transcriptomes from five nanoflagellate grazers provided with or without Synechococcus prey. Transcriptomes were sequenced as part of the Moore Foundation Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP) program. All transcriptomes showed differential gene expression in the presence of Synechococcus CC9311. No genes were found to be up-regulated in all five grazers, but 18 genes were up-regulated more than two fold in at least three grazers grown with CC9311, and two of the 18 genes were up-regulated in four grazers. These were a c-type lectin-like gene and an ankyrin repeat gene and the respective proteins would be likely candidates for Synechococcus binding/recognition by grazers. These results will likely help to interpret metatranscriptome studies in marine environments.