An Investigation into the Transcriptomics of Macroalgal Blooms

The macroalgal genus Ulva, commonly known as “sea lettuce”, develops into harmful macroalgal blooms (dense, floating aggregations) in shallow coastal systems worldwide, including Narragansett Bay, RI. These blooms have significant negative ecological and economic impacts on coastal communities. However, little data exist on the genetic makeup and underling functional genetics that link bloom dynamics to environmental changes, especially with respect to global warming.  To this end, we embarked on a one-year genomics study to begin to understand the link between gene expression changes, bloom dynamics and environment.  This was completed by sampling two abundant bloom-forming Ulva species at three sites around the Narragansett Bay, RI at relevant stages of the bloom cycle.  After collection, species were identified and RNA was extracted and sequenced using HiSeq 2000 NGS technology.  The resulting sequence was assembled using Geneious, and was annotated using Blast2Go.  These data combined indicated large gene expression changes throughout the year that could be indicative of bloom formation providing one of the first insights to the transcriptional regualtion of this behavior.  Moreover, some individual gene expression profiles can be leveraged to act as markers to predict macroalgal blooms.