16 Works

Data from: Conjugation is necessary for a bacterial plasmid to survive under protozoan predation

Johannes Cairns, Matti Jalasvuori, Ville Ojala, Michael Brockhurst & Teppo Hiltunen
Horizontal gene transfer by conjugative plasmids plays a critical role in the evolution of antibiotic resistance. Interactions between bacteria and other organisms can affect the persistence and spread of conjugative plasmids. Here we show that protozoan predation increased the persistence and spread of the antibiotic resistance plasmid RP4 in populations of the opportunist bacterial pathogen Serratia marcescens. A conjugation-defective mutant plasmid was unable to survive under predation, suggesting that conjugative transfer is required for plasmid...

Data from: Temporal dynamics of Puumala hantavirus infection in cyclic populations of bank voles

Liina Voutilainen, Eva R. Kallio, Jukka Niemimaa, Olli Vapalahti & Heikki Henttonen
Understanding the dynamics of zoonotic pathogens in their reservoir host populations is a prerequisite for predicting and preventing human disease epidemics. The human infection risk of Puumala hantavirus (PUUV) is highest in northern Europe, where populations of the rodent host (bank vole, Myodes glareolus) undergo cyclic fluctuations. We conducted a 7-year capture-mark-recapture study to monitor seasonal and multiannual patterns of the PUUV infection rate in bank vole populations exhibiting a 3-year density cycle. Infected bank...

Data from: DNA methylation and potential for epigenetic regulation in Pygospio elegans

Jenni E. Kesäniemi, Liisa Heikkinen & K. Emily Knott
Transitions in developmental mode are common evolutionarily, but how and why they occur is not understood. Developmental mode describes larval phenotypes, including morphology, ecology and behavior of larvae, which typically are generalized across different species. The polychaete worm Pygospio elegans is one of few species polymorphic in developmental mode, with multiple larval phenotypes, providing a possibility to examine the potential mechanisms allowing transitions in developmental mode. We investigated the presence of DNA methylation in P....

Data from: Evolution of bacterial life history traits is sensitive to community structure

Tarmo Ketola, Lauri Mikonranta & Johanna Mappes
Very few studies have experimentally assessed the evolutionary effects of species interactions within the same trophic level. Here we show that when Serratia marcescens evolve in multispecies communities, their growth rate exceeds the growth rate of the bacteria that evolved alone, whereas the biomass yield gets lower. In addition to the community effects per se, we found that few species in the communities caused strong effects on S. marcescens evolution. The results indicate that evolutionary...

Data from: Genomic evolution of bacterial populations under co-selection by antibiotics and phage

Johannes Cairns, Jens Frickel, Matti Jalasvuori, Teppo Hiltunen & Lutz Becks
Bacteria live in dynamic systems where selection pressures can alter rapidly, forcing adaptation to the prevailing conditions. In particular, bacteriophages and antibiotics of anthropogenic origin are major bacterial stressors in many environments. We previously observed that populations of the bacterium Pseudomonas fluorescens SBW25 exposed to the lytic bacteriophage SBW25Φ2 and a non-inhibitive concentration of the antibiotic streptomycin (co-selection) achieved higher levels of phage resistance compared to populations exposed to the phage alone. In addition, the...

Data from: Food limitation constrains host immune responses to nematode infections

Kristian M. Forbes, Tapio Mappes, Tarja Sironen, Tomas Strandin, Peter Stuart, Seppo Meri, Olli Vapalahti, Heikki Henttonen & Otso Huitu
Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles (Microtus agrestis) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal...

Data from: Different food sources elicit fast changes to bacterial virulence

Tarmo Ketola, L. Mikonranta, Jouni Laakso & Johanna Mappes
Environmentally transmitted, opportunistic bacterial pathogens have a life cycle that alternates between hosts and environmental reservoirs. Resources are often scarce and fluctuating in the outside-host environment, whereas overcoming the host immune system could allow pathogens to establish a new, resource abundant and stable niche within the host. We tested if shortterm exposure to different outside-host resource types and concentrations affect Serratia marcescens—(bacterium)’s virulence in Galleria mellonella (moth). As expected, virulence was mostly dictated by the...

Data from: Intensive aquaculture selects for increased virulence and interference competition in bacteria

Lotta-Riina Sundberg, Tarmo Ketola, Elina Laanto, Hanna Kinnula, Reetta Penttinen, Jaana K. H. Bamford & Johanna Mappes
Although increased disease severity driven by intensive farming practices is problematic in food production, the role of evolutionary change in disease is not well understood in these environments. Experiments on parasite evolution are traditionally conducted using laboratory models, often unrelated to economically important systems. We compared how the virulence, growth and competitive ability of a globally important fish pathogen, Flavobacterium columnare, change under intensive aquaculture. We characterized bacterial isolates from disease outbreaks at fish farms...

Data from: Carry-over effects of conditions at the wintering grounds on breeding plumage signals in a migratory bird: roles of phenotypic plasticity and selection

Pauliina E. Järvistö, Sara Calhim, Wiebke Schuett, Päivi Maria Sirkiä, William Velmala & Toni Laaksonen
To understand the consequences of ever-changing environment on the dynamics of phenotypic traits, distinguishing between selection processes and individual plasticity is crucial. We examined individual consistency/plasticity in several male secondary sexual traits expressed during the breeding season (white wing and forehead patch size, UV reflectance of white wing patch and dorsal melanin colouration) in a migratory pied flycatcher (Ficedula hypoleuca) population over an 11-year period. Furthermore, we studied carry-over effects of three environmental variables (NAO,...

Data from: Parasite infection in a central sensory organ of fish does not affect host personality

Ines Klemme, Raine Kortet & Anssi Karvonen
Among the ecological factors acting on the evolution and expression of animal personalities and behavioral syndromes, parasitism has received comparatively little attention. However, infection and host behavior are often strongly intertwined, because host behavior can predict the risk of infection and can also be changed by an infection. We conducted a controlled experimental infection study to explore the effects of infection on host boldness, exploration and activity using rainbow trout Oncorhynchus mykiss and its trematode...

Data from: Learned parasite avoidance is driven by host personality and resistance to infection in a fish–trematode interaction

Ines Klemme & Anssi Karvonen
Cognitive abilities related to the assessment of risk improve survival. While earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. In a series of behavioural trials with the trematode parasite Diplostomum pseudospathaceum, we asked whether sea trout (Salmo trutta trutta) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection mediated through...

Data from: A mechanistic underpinning for sigmoid dose-dependent infection

Jani Anttila, Lauri Mikonranta, Tarmo Ketola, Veijo Kaitala, Jouni Laakso & Lasse Ruokolainen
Theoretical models of environmentally transmitted diseases often assume that transmission is a constant process, which scales linearly with pathogen dose. Here we question the applicability of such an assumption and propose a sigmoidal form for the pathogens infectivity response. In our formulation, this response arises under two assumptions: 1) multiple invasion events are required for a successful pathogen infection and 2) the host invasion state is reversible. The first assumption reduces pathogen infection rates at...

Data from: Wood-inhabiting fungi with tight associations with other species have declined as a response to forest management

Nerea Abrego, David Dunson, Panu Halme, Isabel Salcedo & Otso Ovaskainen
Research on mutualistic and antagonistic networks, such as plant–pollinator and host–parasite networks, has shown that species interactions can influence and be influenced by the responses of species to environmental perturbations. Here we examine whether results obtained for directly observable networks generalize to more complex networks in which species interactions cannot be observed directly. As a case study, we consider data on the occurrences of 98 wood-inhabiting fungal species in managed and natural forests. We specifically...

Data from: Postmating-prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition

Outi Ala-Honkola, Michael G. Ritchie & Paris Veltsos
Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early-stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate...

Data from: Sublethal streptomycin concentrations and lytic bacteriophage together promote resistance evolution

Johannes Cairns, Lutz Becks, Matti Jalasvuori & Teppo Hiltunen
Sub-minimum inhibiting concentrations (sub-MICs) of antibiotics frequently occur in natural environments owing to wide-spread antibiotic leakage by human action. Even though the concentrations are very low, these sub-MICs have recently been shown to alter bacterial populations by selecting for antibiotic resistance and increasing the rate of adaptive evolution. However, studies are lacking on how these effects reverberate into key ecological interactions, such as bacteria–phage interactions. Previously, co-selection of bacteria by phages and antibiotic concentrations exceeding...

Data from: Primary production calculations for sea ice from bio-optical observations in the Baltic Sea

Susann Müller, Anssi V. Vähätalo, Jari Uusikivi, Markus Majaneva, Sanna Majaneva, Riitta Autio & Janne-Markus Rintala
Bio-optics is a powerful approach for estimating photosynthesis rates, but has seldom been applied to sea ice, where measuring photosynthesis is a challenge. We measured absorption coefficients of chromophoric dissolved organic matter (CDOM), algae, and non-algal particles along with solar radiation, albedo and transmittance at four sea-ice stations in the Gulf of Finland, Baltic Sea. This unique compilation of optical and biological data for Baltic Sea ice was used to build a radiative transfer model...

Registration Year

  • 2016

Resource Types

  • Dataset


  • University of Jyväskylä
  • University of Helsinki
  • Natural Resources Institute Finland
  • Max Planck Institute for Evolutionary Biology
  • University of the Basque Country
  • University of Eastern Finland
  • University of Hamburg
  • Duke University
  • Finnish Environment Institute
  • University of Lausanne