Browsing by Subject "Symbiosis"

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  • Pino-Bodas, Raquel; Stenroos, Soili (2021)
    The diversity of lichen photobionts is not fully known. We studied here the diversity of the photobionts associated with Cladonia, a sub-cosmopolitan genus ecologically important, whose photobionts belong to the green algae genus Asterochloris. The genetic diversity of Asterochloris was screened by using the ITS rDNA and actin type I regions in 223 specimens and 135 species of Cladonia collected all over the world. These data, added to those available in GenBank, were compiled in a dataset of altogether 545 Asterochloris sequences occurring in 172 species of Cladonia. A high diversity of Asterochloris associated with Cladonia was found. The commonest photobiont lineages associated with this genus are A. glomerata, A. italiana, and A. mediterranea. Analyses of partitioned variation were carried out in order to elucidate the relative influence on the photobiont genetic variation of the following factors: mycobiont identity, geographic distribution, climate, and mycobiont phylogeny. The mycobiont identity and climate were found to be the main drivers for the genetic variation of Asterochloris. The geographical distribution of the different Asterochloris lineages was described. Some lineages showed a clear dominance in one or several climatic regions. In addition, the specificity and the selectivity were studied for 18 species of Cladonia. Potentially specialist and generalist species of Cladonia were identified. A correlation was found between the sexual reproduction frequency of the host and the frequency of certain Asterochloris OTUs. Some Asterochloris lineages co-occur with higher frequency than randomly expected in the Cladonia species.
  • Amin, Md. Tarique (Helsingfors universitet, 2016)
    Plants interact with mutualists and antagonists both below- and aboveground. However, while we know much about the distribution of plants and their aboveground attackers, we lack a thorough understanding of the distribution of the belowground biota. Importantly, recent research shows that the below- and aboveground biota can interact, and there are numerous factors both belowground and aboveground that are involved in these interactions. It is difficult to assess these dynamic interactions that occur within complex communities and which may affect and alter community structure both belowground and aboveground. Here, I set out to investigate these ecological interactions within a plant-mycorrhiza-insect system. I concentrated exclusively on the role of mycorrhizae as the belowground player. I used the larvae of the Glanville fritillary butterfly (Melitaea cinxia) as an aboveground herbivore. I measured the performance of the herbaceous plant (Plantago lanceolata) and the insect larvae to make inference on the plant response and plant-mediated interactions. My results showed that the growth of the experimental plant, P. lanceolata, was, on average, not directly affected by mycorrhizal treatment. Instead, plant-lines responded differently to the impact of mycorrhizal inoculation. This outcome possibly suggests that plant genotypes coming from different populations are interacting differently (in terms of plant growth) to the mycorrhizal treatment. Similarly, aboveground larvae feeding on the same host plant also responded differently to the impact of mycorrhizal inoculation. Larval performance in terms of growth and days to diapause significantly differed between larval families. It may suggest that these features of larval performance might depend more on their family background compared to the type of host plants (with or without mycorrhizae) they are feeding on. Overall, my findings suggest that mycorrhizal fungi affect the performance of the plant and the insects that feed upon the plant, but that genetic variation exists among both plants and larvae in how they are affected by mycorrhizal infection.
  • Duplouy, Anne; Pranter, Robin; Warren-Gash, Haydon; Tropek, Robert; Wahlberg, Niklas (BioMed Central, 2020)
    Abstract Background Phylogenetically closely related strains of maternally inherited endosymbiotic bacteria are often found in phylogenetically divergent, and geographically distant insect host species. The interspecies transfer of the symbiont Wolbachia has been thought to have occurred repeatedly, facilitating its observed global pandemic. Few ecological interactions have been proposed as potential routes for the horizontal transfer of Wolbachia within natural insect communities. These routes are however likely to act only at the local scale, but how they may support the global distribution of some Wolbachia strains remains unclear. Results Here, we characterize the Wolbachia diversity in butterflies from the tropical forest regions of central Africa to discuss transfer at both local and global scales. We show that numerous species from both the Mylothris (family Pieridae) and Bicyclus (family Nymphalidae) butterfly genera are infected with similar Wolbachia strains, despite only minor interclade contacts across the life cycles of the species within their partially overlapping ecological niches. The phylogenetic distance and differences in resource use between these genera rule out the role of ancestry, hybridization, and shared host-plants in the interspecies transfer of the symbiont. Furthermore, we could not identify any shared ecological factors to explain the presence of the strains in other arthropod species from other habitats, or even ecoregions. Conclusion Only the systematic surveys of the Wolbachia strains from entire species communities may offer the material currently lacking for understanding how Wolbachia may transfer between highly different and unrelated hosts, as well as across environmental scales.
  • Duplouy, Anne; Pranter, Robin; Warren-Gash, Haydon; Tropek, Robert; Wahlberg, Niklas (2020)
    Background Phylogenetically closely related strains of maternally inherited endosymbiotic bacteria are often found in phylogenetically divergent, and geographically distant insect host species. The interspecies transfer of the symbiont Wolbachia has been thought to have occurred repeatedly, facilitating its observed global pandemic. Few ecological interactions have been proposed as potential routes for the horizontal transfer of Wolbachia within natural insect communities. These routes are however likely to act only at the local scale, but how they may support the global distribution of some Wolbachia strains remains unclear. Results Here, we characterize the Wolbachia diversity in butterflies from the tropical forest regions of central Africa to discuss transfer at both local and global scales. We show that numerous species from both the Mylothris (family Pieridae) and Bicyclus (family Nymphalidae) butterfly genera are infected with similar Wolbachia strains, despite only minor interclade contacts across the life cycles of the species within their partially overlapping ecological niches. The phylogenetic distance and differences in resource use between these genera rule out the role of ancestry, hybridization, and shared host-plants in the interspecies transfer of the symbiont. Furthermore, we could not identify any shared ecological factors to explain the presence of the strains in other arthropod species from other habitats, or even ecoregions. Conclusion Only the systematic surveys of the Wolbachia strains from entire species communities may offer the material currently lacking for understanding how Wolbachia may transfer between highly different and unrelated hosts, as well as across environmental scales.
  • Duplouy, Anne; Brattström, Oskar (2018)
    Bicyclus butterflies are key species for studies of wing pattern development, phenotypic plasticity, speciation and the genetics of Lepidoptera. One of the key endosymbionts in butterflies, the alpha-Proteobacterium Wolbachia pipientis, is affecting many of these biological processes; however, Bicyclus butterflies have not been investigated systematically as hosts to Wolbachia. In this study, we screen for Wolbachia infection in several Bicyclus species from natural populations across Africa as well as two laboratory populations. Out of the 24 species tested, 19 were found to be infected, and no double infection was found, but both A- and B-supergroup strains colonise this butterfly group. We also show that many of the Wolbachia strains identified in Bicyclus butterflies belong to the ST19 clonal complex. We discuss the importance of our results in regard to routinely screening for Wolbachia when using Bicyclus butterflies as the study organism of research in eco-evolutionary biology.