Diatoms are photosynthetic microorganisms found in both freshwater and marine ecosystems. They fix as much as 40 percent of the global ocean carbon. The DOE JGI has sequenced two diatoms: Thalassiosira pseudonana and Phaeodactylum tricornutum, and has made available the complete draft genome of a third, Fragillariopsis cylindrus. Neither of these species demonstrate a typical diatom life cycle however so researchers intend to remedy this by sequencing four genomes representative of two types of diatoms, centric and pinnate. They also intend to specifically study the transcriptomes of these four diatoms that are related to the three whose genomes are already available.
If the genome is the complete genetic sequence of an organism, then the transcriptome is the portion of the genome that is transcribed into RNA molecules to carry out instructions to build and maintain cells. Studying the transcriptome allows researchers to learn more about the makeup of particular cell types and how they function. Additionally, by comparing the transcriptomes of these cell types to the genomes as a whole, the researchers gain insight into what genes are active in each cell type, which could help them determine the functions of specific genes.
Photo: T. pseudonana by Nils Kröger, Universität Regensburg
Principal Investigators: Jeroen Gillard, Ghent University
Program: CSP 2010