TY - JOUR
T1 - Pathogen contingency loci and the evolution of host specificity
T2 - Simple sequence repeats mediate Bartonella adaptation to a wild rodent host
AU - Rodríguez-Pastor, Ruth
AU - Knossow, Nadav
AU - Shahar, Naama
AU - Hasik, Adam Z.
AU - Deatherage, Daniel E.
AU - Gutiérrez, Ricardo
AU - Harrus, Shimon
AU - Zaman, Luis
AU - Lenski, Richard E.
AU - Barrick, Jeffrey E.
AU - Hawlena, Hadas
N1 - Publisher Copyright:
© 2024 Rodríguez-Pastor et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2024/9
Y1 - 2024/9
N2 - Parasites, including pathogens, can adapt to better exploit their hosts on many scales, ranging from within an infection of a single individual to series of infections spanning multiple host species. However, little is known about how the genomes of parasites in natural communities evolve when they face diverse hosts. We investigated how Bartonella bacteria that circulate in rodent communities in the dunes of the Negev Desert in Israel adapt to different species of rodent hosts. We propagated 15 Bartonella populations through infections of either a single host species (Gerbillus andersoni or Gerbillus pyramidum) or alternating between the two. After 20 rodent passages, strains with de novo mutations replaced the ancestor in most populations. Mutations in two mononucleotide simple sequence repeats (SSRs) that caused frameshifts in the same adhesin gene dominated the evolutionary dynamics. They appeared exclusively in populations that encountered G. andersoni and altered the dynamics of infections of this host. Similar SSRs in other genes are conserved and exhibit ON/OFF variation in Bartonella isolates from the Negev Desert dunes. Our results suggest that SSR-based contingency loci could be important not only for rapidly and reversibly generating antigenic variation to escape immune responses but that they may also mediate the evolution of host specificity.
AB - Parasites, including pathogens, can adapt to better exploit their hosts on many scales, ranging from within an infection of a single individual to series of infections spanning multiple host species. However, little is known about how the genomes of parasites in natural communities evolve when they face diverse hosts. We investigated how Bartonella bacteria that circulate in rodent communities in the dunes of the Negev Desert in Israel adapt to different species of rodent hosts. We propagated 15 Bartonella populations through infections of either a single host species (Gerbillus andersoni or Gerbillus pyramidum) or alternating between the two. After 20 rodent passages, strains with de novo mutations replaced the ancestor in most populations. Mutations in two mononucleotide simple sequence repeats (SSRs) that caused frameshifts in the same adhesin gene dominated the evolutionary dynamics. They appeared exclusively in populations that encountered G. andersoni and altered the dynamics of infections of this host. Similar SSRs in other genes are conserved and exhibit ON/OFF variation in Bartonella isolates from the Negev Desert dunes. Our results suggest that SSR-based contingency loci could be important not only for rapidly and reversibly generating antigenic variation to escape immune responses but that they may also mediate the evolution of host specificity.
UR - http://www.scopus.com/inward/record.url?scp=85205561834&partnerID=8YFLogxK
U2 - 10.1371/journal.ppat.1012591
DO - 10.1371/journal.ppat.1012591
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C2 - 39348417
AN - SCOPUS:85205561834
SN - 1553-7366
VL - 20
JO - PLoS Pathogens
JF - PLoS Pathogens
IS - 9 September
M1 - e1012591
ER -