Homologous recombination between genetically divergent campylobacter fetus lineages supports host-associated speciation

Maarten J. Gilbert*, Birgitta Duim, Linda van der Graaf-van Bloois, Jaap A. Wagenaar, Aldert L. Zomer

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)

Abstract

Homologous recombination is a major driver of bacterial speciation. Genetic divergence and host association are important factors influencing homologous recombination. Here, we study these factors for Campylobacter fetus, which shows a distinct intraspecific host dichotomy. Campylobacter fetus subspecies fetus (Cff) and venerealis are associated with mammals, whereas C. fetus subsp. testudinum (Cft) is associated with reptiles. Recombination between these genetically divergent C. fetus lineages is extremely rare. Previously it was impossible to show whether this barrier to recombination was determined by the differential host preferences, by the genetic divergence between both lineages or by other factors influencing recombination, such as restriction-modification, CRISPR/Cas, and transformation systems. Fortuitously, a distinct C. fetus lineage (ST69) was found, which was highly related to mammal-associated C. fetus, yet isolated from a chelonian. The whole genome sequences of two C. fetus ST69 isolates were compared with those of mammal- and reptile-associated C. fetus strains for phylogenetic and recombination analysis. In total, 5.1-5.5% of the core genome of both ST69 isolates showed signs of recombination. Of the predicted recombination regions, 80.4% were most closely related to Cft, 14.3% to Cff, and 5.6% to C. iguaniorum. Recombination from C. fetus ST69 to Cft was also detected, but to a lesser extent and only in chelonian-associated Cft strains. This study shows that despite substantial genetic divergence no absolute barrier to homologous recombination exists between two distinct C. fetus lineages when occurring in the same host type, which provides valuable insights in bacterial speciation and evolution.

Original languageEnglish
Pages (from-to)716-722
JournalGenome Biology and Evolution
Volume10
Issue number3
DOIs
Publication statusPublished - 1 Mar 2018

Fingerprint

Campylobacter fetus
Homologous Recombination
homologous recombination
recombination
Genetic Recombination
mammal
Mammals
divergence
Reptiles
reptile
subspecies
CRISPR-Cas Systems
genome
mammals
Fetus
genetic variation
reptiles
host preference
Genome
fetus

Keywords

  • Campylobacter fetus
  • Homologous recombination
  • Host association
  • Reptile
  • Speciation
  • Whole genome sequencing

Cite this

Gilbert, Maarten J. ; Duim, Birgitta ; van der Graaf-van Bloois, Linda ; Wagenaar, Jaap A. ; Zomer, Aldert L. / Homologous recombination between genetically divergent campylobacter fetus lineages supports host-associated speciation. In: Genome Biology and Evolution. 2018 ; Vol. 10, No. 3. pp. 716-722.
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abstract = "Homologous recombination is a major driver of bacterial speciation. Genetic divergence and host association are important factors influencing homologous recombination. Here, we study these factors for Campylobacter fetus, which shows a distinct intraspecific host dichotomy. Campylobacter fetus subspecies fetus (Cff) and venerealis are associated with mammals, whereas C. fetus subsp. testudinum (Cft) is associated with reptiles. Recombination between these genetically divergent C. fetus lineages is extremely rare. Previously it was impossible to show whether this barrier to recombination was determined by the differential host preferences, by the genetic divergence between both lineages or by other factors influencing recombination, such as restriction-modification, CRISPR/Cas, and transformation systems. Fortuitously, a distinct C. fetus lineage (ST69) was found, which was highly related to mammal-associated C. fetus, yet isolated from a chelonian. The whole genome sequences of two C. fetus ST69 isolates were compared with those of mammal- and reptile-associated C. fetus strains for phylogenetic and recombination analysis. In total, 5.1-5.5{\%} of the core genome of both ST69 isolates showed signs of recombination. Of the predicted recombination regions, 80.4{\%} were most closely related to Cft, 14.3{\%} to Cff, and 5.6{\%} to C. iguaniorum. Recombination from C. fetus ST69 to Cft was also detected, but to a lesser extent and only in chelonian-associated Cft strains. This study shows that despite substantial genetic divergence no absolute barrier to homologous recombination exists between two distinct C. fetus lineages when occurring in the same host type, which provides valuable insights in bacterial speciation and evolution.",
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Homologous recombination between genetically divergent campylobacter fetus lineages supports host-associated speciation. / Gilbert, Maarten J.; Duim, Birgitta; van der Graaf-van Bloois, Linda; Wagenaar, Jaap A.; Zomer, Aldert L.

In: Genome Biology and Evolution, Vol. 10, No. 3, 01.03.2018, p. 716-722.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Homologous recombination between genetically divergent campylobacter fetus lineages supports host-associated speciation

AU - Gilbert, Maarten J.

AU - Duim, Birgitta

AU - van der Graaf-van Bloois, Linda

AU - Wagenaar, Jaap A.

AU - Zomer, Aldert L.

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N2 - Homologous recombination is a major driver of bacterial speciation. Genetic divergence and host association are important factors influencing homologous recombination. Here, we study these factors for Campylobacter fetus, which shows a distinct intraspecific host dichotomy. Campylobacter fetus subspecies fetus (Cff) and venerealis are associated with mammals, whereas C. fetus subsp. testudinum (Cft) is associated with reptiles. Recombination between these genetically divergent C. fetus lineages is extremely rare. Previously it was impossible to show whether this barrier to recombination was determined by the differential host preferences, by the genetic divergence between both lineages or by other factors influencing recombination, such as restriction-modification, CRISPR/Cas, and transformation systems. Fortuitously, a distinct C. fetus lineage (ST69) was found, which was highly related to mammal-associated C. fetus, yet isolated from a chelonian. The whole genome sequences of two C. fetus ST69 isolates were compared with those of mammal- and reptile-associated C. fetus strains for phylogenetic and recombination analysis. In total, 5.1-5.5% of the core genome of both ST69 isolates showed signs of recombination. Of the predicted recombination regions, 80.4% were most closely related to Cft, 14.3% to Cff, and 5.6% to C. iguaniorum. Recombination from C. fetus ST69 to Cft was also detected, but to a lesser extent and only in chelonian-associated Cft strains. This study shows that despite substantial genetic divergence no absolute barrier to homologous recombination exists between two distinct C. fetus lineages when occurring in the same host type, which provides valuable insights in bacterial speciation and evolution.

AB - Homologous recombination is a major driver of bacterial speciation. Genetic divergence and host association are important factors influencing homologous recombination. Here, we study these factors for Campylobacter fetus, which shows a distinct intraspecific host dichotomy. Campylobacter fetus subspecies fetus (Cff) and venerealis are associated with mammals, whereas C. fetus subsp. testudinum (Cft) is associated with reptiles. Recombination between these genetically divergent C. fetus lineages is extremely rare. Previously it was impossible to show whether this barrier to recombination was determined by the differential host preferences, by the genetic divergence between both lineages or by other factors influencing recombination, such as restriction-modification, CRISPR/Cas, and transformation systems. Fortuitously, a distinct C. fetus lineage (ST69) was found, which was highly related to mammal-associated C. fetus, yet isolated from a chelonian. The whole genome sequences of two C. fetus ST69 isolates were compared with those of mammal- and reptile-associated C. fetus strains for phylogenetic and recombination analysis. In total, 5.1-5.5% of the core genome of both ST69 isolates showed signs of recombination. Of the predicted recombination regions, 80.4% were most closely related to Cft, 14.3% to Cff, and 5.6% to C. iguaniorum. Recombination from C. fetus ST69 to Cft was also detected, but to a lesser extent and only in chelonian-associated Cft strains. This study shows that despite substantial genetic divergence no absolute barrier to homologous recombination exists between two distinct C. fetus lineages when occurring in the same host type, which provides valuable insights in bacterial speciation and evolution.

KW - Campylobacter fetus

KW - Homologous recombination

KW - Host association

KW - Reptile

KW - Speciation

KW - Whole genome sequencing

U2 - 10.1093/gbe/evy048

DO - 10.1093/gbe/evy048

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SP - 716

EP - 722

JO - Genome Biology and Evolution

JF - Genome Biology and Evolution

SN - 1759-6653

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