Genetic Architecture and Fitness of Bacterial Interspecies Hybrids

© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution..

Integration of a conjugative plasmid into a bacterial chromosome can promote the transfer of chromosomal DNA to other bacteria. Intraspecies chromosomal conjugation is believed responsible for creating the global pathogens Klebsiella pneumoniae ST258 and Escherichia coli ST1193. Interspecies conjugation is also possible but little is known about the genetic architecture or fitness of such hybrids. To study this, we generated by conjugation 14 hybrids of E. coli and Salmonella enterica. These species belong to different genera, diverged from a common ancestor >100 Ma, and share a conserved order of orthologous genes with ∼15% nucleotide divergence. Genomic analysis revealed that all but one hybrid had acquired a contiguous segment of donor E. coli DNA, replacing a homologous region of recipient Salmonella chromosome, and ranging in size from ∼100 to >4,000 kb. Recombination joints occurred in sequences with higher-than-average nucleotide identity. Most hybrid strains suffered a large reduction in growth rate, but the magnitude of this cost did not correlate with the length of foreign DNA. Compensatory evolution to ameliorate the cost of low-fitness hybrids pointed towards disruption of complex genetic networks as a cause. Most interestingly, 4 of the 14 hybrids, in which from 45% to 90% of the Salmonella chromosome was replaced with E. coli DNA, showed no significant reduction in growth fitness. These data suggest that the barriers to creating high-fitness interspecies hybrids may be significantly lower than generally appreciated with implications for the creation of novel species.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:38

Enthalten in:

Molecular biology and evolution - 38(2021), 4 vom: 13. Apr., Seite 1472-1481

Sprache:

Englisch

Beteiligte Personen:

Bartke, Katrin [VerfasserIn]
Garoff, Linnéa [VerfasserIn]
Huseby, Douglas L [VerfasserIn]
Brandis, Gerrit [VerfasserIn]
Hughes, Diarmaid [VerfasserIn]

Links:

Volltext

Themen:

Conjugation
Escherichia coli
Experimental evolution
Journal Article
Recombination
Relative fitness
Research Support, Non-U.S. Gov't
Salmonella Typhimurium

Anmerkungen:

Date Completed 15.07.2021

Date Revised 31.03.2024

published: Print

Citation Status MEDLINE

doi:

10.1093/molbev/msaa307

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM318141396