Abstract
BackgroundHost specificity is one of the outputs of the coevolution between parasites and their associated hosts. Several scenarios have been proposed to explain the pattern of parasite distribution in parental and hybrid genotypes ranging from hybrid resistance to hybrid susceptibility. We hypothesized that host-parasite co-adaptation limits the infection of host-specific parasites in hybrid genotypes even under the condition of the high frequency of hybrids. The experimental monogenean infection in pure breeds of Blicca bjoerkna and Abramis brama and cross-breeds (the F1 generation of hybrids) under the condition of similar frequencies of pure and hybrid genotypes was investigated. We also examined the potential effect of the maternal origin of hybrids (potential co-adaptation at the level of mitochondrial genes) on monogenean abundance.MethodsPure breeds of two cyprinids and two cross-breeds (one with B. bjoerkna, the next with A. brama in the maternal positions) were exposed to infection by monogeneans naturally occurring in B. bjoerkna and A. brama. The experiment was run under similar frequencies of the four breed lines.ResultsWe showed similar levels of monogenean infection in B. bjoerkna and A. brama. However, each species harboured specific monogenean fauna. Hybrids harboured all monogenean species specifically infecting one or the other species. Monogenean infection levels, especially those of Dactylogyrus specific to A. brama, were lower in hybrids. For the majority of host-specific parasites, there was no effect of the maternal origin of hybrids on monogenean abundance. Asymmetry was found in the distribution of specific parasites in favour of specialists of B. bjoerkna in the monogenean communities of hybrids.ConclusionsOur results indicate that the maternal mtDNA of hybrids is not an important predictor of host-specific monogenean infection, which may suggest that mitochondrial genes are not strongly involved in the coadaptation between monogeneans and their associated hosts. The asymmetry of species-specific parasites suggests similarity between the molecular components of the immune mechanisms in hybrids and B. bjoerkna. Our results revealed a difference between the degree of host-parasite coadaptation in specific parasites of A. brama and the degree of host-parasite coadaptation in specific parasites of B. bjoerkna and their associated hosts.
Highlights
Host specificity is one of the outputs of the coevolution between parasites and their associated hosts
Dactylogurus parasites had the dominant position in the monogenean communities of all the investigated fish breed lines (A. brama, B. bjoerkna, F1 hybrids with A. brama maternal origin and F1 hybrids with B. bjoerkna maternal origin)
The monogenean communities of F1 hybrids exhibited higher monogenean species richness in comparison to those of parental species, i.e. all monogenean species found in breed lines of A. brama and B. bjoerkna were present in F1 hybrids
Summary
Host specificity is one of the outputs of the coevolution between parasites and their associated hosts. We hypothesized that host-parasite co-adaptation limits the infection of host-specific parasites in hybrid genotypes even under the condition of the high frequency of hybrids. Wolinska et al [9], in their dynamic scenario, hypothesized that hybrid genomes are more parasitized than parental genomes under the condition of the high frequency of hybrids. It seems that the maternal ancestry of hybrids may influence the infection level of some parasite species, as was shown for digenean and crustacean species in F1 hybrids of the evolutionarily divergent, and morphologically and ecologically different cyprinid species, the common bream (Abramis brama) and roach (Rutilus rutilus) [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
