title: Replication-biased genome organisation in the crenarchaeon Sulfolobus.
abstract: BACKGROUND
  Species of the crenarchaeon Sulfolobus harbour three replication origins in their single circular chromosome that are synchronously initiated during replication.
  
  
  RESULTS
  We demonstrate that global gene expression in two Sulfolobus species is highly biased, such that early replicating genome regions are more highly expressed at all three origins. The bias by far exceeds what would be anticipated by gene dosage effects alone. In addition, early replicating regions are denser in archaeal core genes (enriched in essential functions), display lower intergenic distances, and are devoid of mobile genetic elements.
  
  
  CONCLUSIONS
  The strong replication-biased structuring of the Sulfolobus chromosome implies that the multiple replication origins serve purposes other than simply shortening the time required for replication. The higher-level chromosomal organisation could be of importance for minimizing the impact of DNA damage, and may also be linked to transcriptional regulation.
authors.affiliation: Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden. doubleanders@gmail.com
authors.forename: Anders F
authors.initials: AF
authors.lastname: Andersson
authors.forename: Erik A
authors.initials: EA
authors.lastname: Pelve
authors.forename: Stefan
authors.initials: S
authors.lastname: Lindeberg
authors.forename: Magnus
authors.initials: M
authors.lastname: Lundgren
authors.forename: Peter
authors.initials: P
authors.lastname: Nilsson
authors.forename: Rolf
authors.initials: R
authors.lastname: Bernander
mesh_terms: D019847:Chromosomes, Archaeal / Q000235:genetics; D004261:DNA Replication; D019641:DNA, Archaeal / Q000235:genetics; D020869:Gene Expression Profiling; D020745:Genome, Archaeal / Q000235:genetics*; D023281:Genomics; D016944:Sulfolobus / Q000166:cytology / Q000235:genetics* / Q000254:growth & development
chemical_list: D019641:DNA, Archaeal