title: Cryptic ecology among host generalist Campylobacter jejuni in domestic animals.
abstract: Homologous recombination between bacterial strains is theoretically capable of preventing the separation of daughter clusters, and producing cohesive clouds of genotypes in sequence space. However, numerous barriers to recombination are known. Barriers may be essential such as adaptive incompatibility, or ecological, which is associated with the opportunities for recombination in the natural habitat. Campylobacter jejuni is a gut colonizer of numerous animal species and a major human enteric pathogen. We demonstrate that the two major generalist lineages of C. jejuni do not show evidence of recombination with each other in nature, despite having a high degree of host niche overlap and recombining extensively with specialist lineages. However, transformation experiments show that the generalist lineages readily recombine with one another in vitro. This suggests ecological rather than essential barriers to recombination, caused by a cryptic niche structure within the hosts.
authors.affiliation: Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK; Institute of Life Science, College of Medicine, Swansea University, Swansea, SA2 8PP, UK.
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Sheppard
authors.forename: Lu
authors.initials: L
authors.lastname: Cheng
authors.forename: Guillaume
authors.initials: G
authors.lastname: Méric
authors.forename: Caroline P A
authors.initials: CP
authors.lastname: de Haan
authors.forename: Ann-Katrin
authors.initials: AK
authors.lastname: Llarena
authors.forename: Pekka
authors.initials: P
authors.lastname: Marttinen
authors.forename: Ana
authors.initials: A
authors.lastname: Vidal
authors.forename: Anne
authors.initials: A
authors.lastname: Ridley
authors.forename: Felicity
authors.initials: F
authors.lastname: Clifton-Hadley
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Connor
authors.forename: Norval J C
authors.initials: NJ
authors.lastname: Strachan
authors.forename: Ken
authors.initials: K
authors.lastname: Forbes
authors.forename: Frances M
authors.initials: FM
authors.lastname: Colles
authors.forename: Keith A
authors.initials: KA
authors.lastname: Jolley
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Bentley
authors.forename: Martin C J
authors.initials: MC
authors.lastname: Maiden
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Hänninen
authors.forename: Julian
authors.initials: J
authors.lastname: Parkhill
authors.forename: William P
authors.initials: WP
authors.lastname: Hanage
authors.forename: Jukka
authors.initials: J
authors.lastname: Corander
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D001717:Birds / Q000382:microbiology; D016123:Campylobacter jejuni / Q000145:classification / Q000235:genetics*; D002417:Cattle / Q000382:microbiology; D002645:Chickens / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D016680:Genome, Bacterial; D005838:Genotype; D059765:Homologous Recombination; D058885:Multilocus Sequence Typing; D010802:Phylogeny
chemical_list: D004269:DNA, Bacterial
keywords: Campylobacter; adaptation; genomics; recombination barriers