title: Gene transfer from bacteria and archaea facilitated evolution of an extremophilic eukaryote.
abstract: Some microbial eukaryotes, such as the extremophilic red alga Galdieria sulphuraria, live in hot, toxic metal-rich, acidic environments. To elucidate the underlying molecular mechanisms of adaptation, we sequenced the 13.7-megabase genome of G. sulphuraria. This alga shows an enormous metabolic flexibility, growing either photoautotrophically or heterotrophically on more than 50 carbon sources. Environmental adaptation seems to have been facilitated by horizontal gene transfer from various bacteria and archaea, often followed by gene family expansion. At least 5% of protein-coding genes of G. sulphuraria were probably acquired horizontally. These proteins are involved in ecologically important processes ranging from heavy-metal detoxification to glycerol uptake and metabolism. Thus, our findings show that a pan-domain gene pool has facilitated environmental adaptation in this unicellular eukaryote.
authors.affiliation: Department of Botany, Oklahoma State University, Stillwater, OK 74078, USA. gerald.schoenknecht@okstate.edu
authors.forename: Gerald
authors.initials: G
authors.lastname: Schönknecht
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Chen
authors.forename: Chad M
authors.initials: CM
authors.lastname: Ternes
authors.forename: Guillaume G
authors.initials: GG
authors.lastname: Barbier
authors.forename: Roshan P
authors.initials: RP
authors.lastname: Shrestha
authors.forename: Mario
authors.initials: M
authors.lastname: Stanke
authors.forename: Andrea
authors.initials: A
authors.lastname: Bräutigam
authors.forename: Brett J
authors.initials: BJ
authors.lastname: Baker
authors.forename: Jillian F
authors.initials: JF
authors.lastname: Banfield
authors.forename: R Michael
authors.initials: RM
authors.lastname: Garavito
authors.forename: Kevin
authors.initials: K
authors.lastname: Carr
authors.forename: Curtis
authors.initials: C
authors.lastname: Wilkerson
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Rensing
authors.forename: David
authors.initials: D
authors.lastname: Gagneul
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Dickenson
authors.forename: Christine
authors.initials: C
authors.lastname: Oesterhelt
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Lercher
authors.forename: Andreas P M
authors.initials: AP
authors.lastname: Weber
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000251:Adenosine Triphosphatases / Q000235:genetics; D001105:Archaea / Q000145:classification / Q000235:genetics; D001419:Bacteria / Q000145:classification / Q000235:genetics; D048028:DNA, Algal; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D019766:Genes, Archaeal; D005798:Genes, Bacterial; D018745:Genome, Plant / Q000235:genetics*; D010802:Phylogeny; D000461:Rhodophyta / Q000235:genetics* / Q000382:microbiology* / Q000502:physiology
chemical_list: D048028:DNA, Algal; D000251:Adenosine Triphosphatases