Dynamics of Wolbachia Spread in Rhagoletis cerasi
Abstract
Virtually all animal life depends on bacteria for survival and associations range from pathogenic to mutualistic. A good example of such interactions are bacterial endosymbionts of insects, such as Wolbachia, a ubiquitous maternally inherited microorganism which often induces reproductive manipulations in hosts like cytoplasmic incompatibility (CI). Only very few examples exist to confidently assert how endosymbionts spread through populations, i.e. Fisherian, with positive effects of host fitness or bistable with negative fitness effects where local infection frequencies tend to increase only once the infection becomes sufficiently common. The aim of this proposal is to test how the Wolbachia strain wCer2 spreads in the European cherry fruit fly, Rhagoletis cerasi, a univoltine species with a small dispersal capacity. wCer2 induces unidirectional CI, resulting in embryonic death when wCer2-infected males mate with wCer2-uninfected females. A transect between populations fixed for wCer2 and populations free of wCer2 has been described in 2015, with transitional populations showing a gradual increase of wCer2-infected individuals from south to north. This transect will be screened over ten years and the wCer2-dynamics will be determined. Fitness parameters will be elaborated and incorporated into the theoretical modelling. Furthermore, we aim to analyse the mitochondrial genome of R. cerasi from the transect populations to detect deviations from the associations of mitochondrial haplotypes and wCer2-infected individuals in transitional populations. By applying genome sequencing, we will also be able to compare the wCer1 and wCer2 genomes to detect if co-infecting Wolbachia variants positively interact. Finally, we aim to study the nuclear diversity of R. cerasi on the transect populations to study effects of wCer2 infections on the nuclear genome. Collections in Czech and German transects, PCR screenings, crossing studies, semi-field experiments and high-throughput sequencing of the host genomes and the endosymbiont genomes will provide a detailed understanding of the dynamics. The theoretical approach will test the wave modelling, besides others. Transitional populations are evolutionary hotspots to study Wolbachia dynamics and endosymbiont-host interactions. No comparable system to study the spatio-temporal spread of Wolbachia exists, and indeed, there are very few detailed data on the spread of infections in nature.
Publikationen
Project staff
Christian Stauffer
Ao.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Christian Stauffer
christian.stauffer@boku.ac.at
Tel: +43 1 47654-91631
Project Leader
01.06.2022 - 31.05.2026
Martin Schebeck
Priv.-Doz. Dr.nat.techn. Martin Schebeck MMSc.
martin.schebeck@boku.ac.at
Tel: +43 1 47654-91617
Project Staff
01.06.2022 - 31.05.2026