Carolina Carpenter1
1University of California San Diego, USA
The Giant Kelp, Macrocystis pyrifera, physically spans biologically relevant gradients in light, temperature and nutrients. We examine global transcriptional changes across these environmental gradients using a RNA-Seq approach. From a single water-column spanning individual, RNA was extracted from blades collected every 3m from the surface to 18m depth. Three technical replicates for each of the seven depth samples were prepared for cDNA library construction and sequenced on the Illumina Genome Analyzer IIx. 45 Gbp of raw sequence across the 21 libraries assembled into 23,400 transcripts, greatly expanding the number of annotated transcriptional units for this species. The resulting expression profiles cluster distinctly by depth. Transcripts involved in photosynthesis, carbon metabolism, and photoprotection were highly expressed in the upper canopy of the individual; alternatively, cellular maintenance processes and senescence related activities were dominant at depth in the older blades. Diversity and functional capabilities of associated microbes are also discussed. This work provides new insights into diversification of biochemical and cellular function according to vertical position in the water column in Macrocystis pyrifera and creates a new resource for genome-enabled studies of this ecologically important species.
Biography
Carolina Carpenter is a 5th year PhD student at Scripps Institution of Oceanography working with Prof. Andrew Allen to understand the role of microbial communities on Micro- and Macro algae. As an undergraduate at UC San Diego, she became interested in understanding how keystone species such as coral and algae respond to increases in ocean conditions. Her current research aims to bring insights into how microbial communities play a role in Stramenopiles, specifically in giant kelp and diatoms.