In the grip of algal genomics.

Algae are dominant primary producers on the Earth and have a major impact on global productivity and biogeochemical cycling. There are still few algal genomes that have been completely characterized, and resources directed toward algal genomic sequencing are limited. However, it is also becoming evident that algae and prokaryotic picoplankton have a critical role in the fixation and sequestration of carbon, and so the interest in algal genomics is expanding. There are some algae for which full or near-full genome sequences have been secured; these genomes include those of the red alga Cyanidioschyzon merolae, the green algae or chlorophytes Chlamydomonas reinhardtii and Volvox carteri, the marine picoeukaryote Ostreococcus tauri (two different strains of O. tauri have been sequenced), the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum, and the haptophyte Emiliania huxleyi. There is also a full sequence for the vestigal 'red' algal genome of the nucleomorph of the Cyptomonad Guillardia theta. In addition, numerous genomes of photosynthetic microbes, including marine Synechococcus and Prochlorococcus species have been sequenced. There have also been projects developed to define algal transcriptomes as determined by cDNA analysis, full genome sequences of numerous plastids, and the genomes of a variety of viruses that infect marine and freshwater algae. The recent efforts focused on acquiring and analyzing algal genome sequences have generated an influx of exciting data to a field that is in its infancy. In this review I discuss potential criteria for determining which organisms should be targeted for genome projects, successful forays into algal genomic sequencing, and some of the inferences generated from the analysis of the sequence information.