RT Journal Article
SR Electronic
T1 Bacteria maintain Slightly Beneficial Genes and Selfish Genetic Elements through the evolution of Horizontal Gene Transfer
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.02.13.947077
DO 10.1101/2020.02.13.947077
A1 B. van Dijk
A1 P. Hogeweg
A1 H.M. Doekes
A1 N. Takeuchi
YR 2020
UL http://biorxiv.org/content/early/2020/02/14/2020.02.13.947077.abstract
AB Horizontal gene transfer (HGT) is a key component of bacterial evolution, which in concert with gene loss can result in rapid changes in gene content. While HGT can evidently aid bacteria to adapt to new environments, it also carries risks since bacteria may pick up selfish genetic elements (SGEs). Here, we use modeling to study how bacterial growth rates are affected by HGT of slightly beneficial genes, if bacteria can evolve HGT to improve their growth rates, and when HGT is evolutionarily maintained in light of harmful SGEs. We find that we can distinguish between four classes of slightly beneficial genes: indispensable, enrichable, rescuable, and unrescuable genes. Rescuable genes – genes that confer small fitness benefits and are lost in the absence of HGT — can be collectively retained by a bacterial community that engages in HGT. Although this ‘gene-sharing’ cannot evolve in well-mixed cultures, it does evolve in a spatially structured population such as a biofilm. Although HGT does indeed enable infection by harmful SGEs, HGT is nevertheless evolutionarily maintained by the hosts, explaining the stable coexistence and co-evolution of bacteria and SGEs.