Sammanfattning

Genes that play key roles in host immunity such as the major histocompatibility complex (MHC) in vertebrates are expected to be major targets of selection. It is well known that environmental conditions can have an effect on host-parasite interactions and may thus influence the selection on MHC. We analyzed MHC class II ss variability over 35years in a population of perch (Perca fluviatilis) from the Baltic Sea that was split into two populations separated from each other. One population was subjected to heating from cooling water of a nuclear power plant and was isolated from the surrounding environment in an artificial lake, while the other population was not subjected to any change in water temperature (control). The isolated population experienced a change of the allelic composition and a decrease in allelic richness of MHC genes compared to the control population. The two most common MHC alleles showed cyclic patterns indicating ongoing parasite-host coevolution in both populations, but the alleles that showed a cyclic behavior differed between the two populations. No such patterns were observed at alleles from nine microsatellite loci, and no genetic differentiation was found between populations. We found no indications for a genetic bottleneck in the isolated population during the 35years. Additionally, differences in parasitism of the current perch populations suggest that a change of the parasite communities has occurred over the isolation period, although the evidence in form of in-depth knowledge of the change of the parasite community over time is lacking. Our results are consistent with the hypothesis of a selective sweep imposed by a change in the parasite community.

Nyckelord

MHC II; microsatellites; Perca fluviatilis; selection; time series; warming

Publicerad i

Ecology and Evolution
2015, Volym: 5, nummer: 7, sidor: 1440-1455
Utgivare: WILEY-BLACKWELL

SLU författare

• Aho, Teija

  • Institutionen för akvatiska resurser (SLU Aqua), Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Ekologi
Evolutionsbiologi


Publikationens identifierare

DOI: https://doi.org/10.1002/ece3.1426

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/67424