title: Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae).
abstract: Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼ 40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide synthase/non-ribosomal peptide synthase gene complex reported for an algal species, and encodes potential anti-microbial peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two "red" RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes.
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America.
authors.forename: Blake T
authors.initials: BT
authors.lastname: Hovde
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Chloe R
authors.initials: CR
authors.lastname: Deodato
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Hunsperger
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Ryken
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Will
authors.initials: W
authors.lastname: Yost
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America.
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Jha
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Johnathan
authors.initials: J
authors.lastname: Patterson
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America; University of Washington, Department of Pathology, Seattle, Washington, United States of America.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Monnat
authors.affiliation: Electron Microscope Facility, San Diego State University, San Diego, California, United States of America.
authors.forename: Steven B
authors.initials: SB
authors.lastname: Barlow
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Starkenburg
authors.affiliation: Department of Biology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Rose Ann
authors.initials: RA
authors.lastname: Cattolico
mesh_terms: D001483:Base Sequence; D020869:Gene Expression Profiling; D056084:Genetic Fitness; D016678:Genome / Q000235:genetics*; D058087:Haptophyta / Q000235:genetics*; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D012273:Ribulose-Bisphosphate Carboxylase