title: Pan genome of the phytoplankton Emiliania underpins its global distribution.
abstract: Coccolithophores have influenced the global climate for over 200 million years. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering them visible from space. Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate that E. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.
authors.affiliation: Department of Biological Sciences, California State University San Marcos, San Marcos, California 92096, USA.
authors.forename: Betsy A
authors.initials: BA
authors.lastname: Read
authors.forename: Jessica
authors.initials: J
authors.lastname: Kegel
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Klute
authors.forename: Alan
authors.initials: A
authors.lastname: Kuo
authors.forename: Stephane C
authors.initials: SC
authors.lastname: Lefebvre
authors.forename: Florian
authors.initials: F
authors.lastname: Maumus
authors.forename: Christoph
authors.initials: C
authors.lastname: Mayer
authors.forename: John
authors.initials: J
authors.lastname: Miller
authors.forename: Adam
authors.initials: A
authors.lastname: Monier
authors.forename: Asaf
authors.initials: A
authors.lastname: Salamov
authors.forename: Jeremy
authors.initials: J
authors.lastname: Young
authors.forename: Maria
authors.initials: M
authors.lastname: Aguilar
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Claverie
authors.forename: Stephan
authors.initials: S
authors.lastname: Frickenhaus
authors.forename: Karina
authors.initials: K
authors.lastname: Gonzalez
authors.forename: Emily K
authors.initials: EK
authors.lastname: Herman
authors.forename: Yao-Cheng
authors.initials: YC
authors.lastname: Lin
authors.forename: Johnathan
authors.initials: J
authors.lastname: Napier
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ogata
authors.forename: Analissa F
authors.initials: AF
authors.lastname: Sarno
authors.forename: Jeremy
authors.initials: J
authors.lastname: Shmutz
authors.forename: Declan
authors.initials: D
authors.lastname: Schroeder
authors.forename: Colomban
authors.initials: C
authors.lastname: de Vargas
authors.forename: Frederic
authors.initials: F
authors.lastname: Verret
authors.forename: Peter
authors.initials: P
authors.lastname: von Dassow
authors.forename: Klaus
authors.initials: K
authors.lastname: Valentin
authors.forename: Yves
authors.initials: Y
authors.lastname: Van de Peer
authors.forename: Glen
authors.initials: G
authors.lastname: Wheeler
authors.forename: Joel B
authors.initials: JB
authors.lastname: Dacks
authors.forename: Charles F
authors.initials: CF
authors.lastname: Delwiche
authors.forename: Sonya T
authors.initials: ST
authors.lastname: Dyhrman
authors.forename: Gernot
authors.initials: G
authors.lastname: Glöckner
authors.forename: Uwe
authors.initials: U
authors.lastname: John
authors.forename: Thomas
authors.initials: T
authors.lastname: Richards
authors.forename: Alexandra Z
authors.initials: AZ
authors.lastname: Worden
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Igor V
authors.initials: IV
authors.lastname: Grigoriev
mesh_terms: D002113:Calcification, Physiologic; D002118:Calcium / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000235:genetics / Q000378:metabolism; D017753:Ecosystem; D016678:Genome / Q000235:genetics*; D058087:Haptophyta / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D009792:Oceans and Seas; D010802:Phylogeny; D010839:Phytoplankton / Q000235:genetics*; D020543:Proteome / Q000235:genetics; D012623:Seawater
chemical_list: D020543:Proteome; D002256:Carbonic Anhydrases; D002118:Calcium