Positive selection has shaped the evolution of Argentine ant immune genes both in native and introduced supercolonies
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Positive selection has shaped the evolution of Argentine ant immune genes both in native and introduced supercolonies. / Holmberg, Ida; Tolonen, Lassi; Paviala, Jenni; Pedersen, Jes Søe; Helanterä, Heikki; Viljakainen, Lumi.
In: Journal of Evolutionary Biology, Vol. 37, No. 2, 2024, p. 131–140.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Positive selection has shaped the evolution of Argentine ant immune genes both in native and introduced supercolonies
AU - Holmberg, Ida
AU - Tolonen, Lassi
AU - Paviala, Jenni
AU - Pedersen, Jes Søe
AU - Helanterä, Heikki
AU - Viljakainen, Lumi
PY - 2024
Y1 - 2024
N2 - The highly invasive Argentine ant (Linepithema humile) started its colonisation from the species’ native range in South America approximately 150 years ago and has since become one of the major pests in the world. We investigated how the shifts into new ranges have affected the evolution of Argentine ants’ immune genes. To the best of our knowledge, this is the first broadscale population genetic study focusing on ants’ immune genes. We analysed comprehensive targeted-seq data of immune and non-immune genes containing 174 genes from 18 Argentine ant supercolonies covering the species’ native and introduced ranges. We predicted that the immune gene evolution of introduced supercolonies differs from that of the native supercolonies and proposed two different, non-mutually exclusive hypotheses for this: 1) the enemy release hypothesis and 2) the higher pathogen pressure hypothesis – both of which seem to explain the observed evolutionary patterns on their behalf. Our results show that the introduced supercolonies were targeted by weaker selection than natives, but positive selection was evident among supercolonies of both ranges. Moreover, in some cases, such as the antiviral RNAi genes, introduced range supercolonies harboured a higher proportion of positively selected genes than natives. This observation was striking, knowing the recent demographic history and the detected generally lower selection efficacy of introduced supercolonies. In conclusion, it is evident that pathogen pressure is ubiquitous and strongly affects the immune gene evolution in Argentine ants.
AB - The highly invasive Argentine ant (Linepithema humile) started its colonisation from the species’ native range in South America approximately 150 years ago and has since become one of the major pests in the world. We investigated how the shifts into new ranges have affected the evolution of Argentine ants’ immune genes. To the best of our knowledge, this is the first broadscale population genetic study focusing on ants’ immune genes. We analysed comprehensive targeted-seq data of immune and non-immune genes containing 174 genes from 18 Argentine ant supercolonies covering the species’ native and introduced ranges. We predicted that the immune gene evolution of introduced supercolonies differs from that of the native supercolonies and proposed two different, non-mutually exclusive hypotheses for this: 1) the enemy release hypothesis and 2) the higher pathogen pressure hypothesis – both of which seem to explain the observed evolutionary patterns on their behalf. Our results show that the introduced supercolonies were targeted by weaker selection than natives, but positive selection was evident among supercolonies of both ranges. Moreover, in some cases, such as the antiviral RNAi genes, introduced range supercolonies harboured a higher proportion of positively selected genes than natives. This observation was striking, knowing the recent demographic history and the detected generally lower selection efficacy of introduced supercolonies. In conclusion, it is evident that pathogen pressure is ubiquitous and strongly affects the immune gene evolution in Argentine ants.
U2 - 10.1093/jeb/voad014
DO - 10.1093/jeb/voad014
M3 - Journal article
C2 - 38366252
VL - 37
SP - 131
EP - 140
JO - Journal of Evolutionary Biology
JF - Journal of Evolutionary Biology
SN - 1420-9101
IS - 2
ER -
ID: 381224966