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Abstracts

  1. Amaia Green Etxabe
  2. Anders Blomberg
  3. Anna Kuparinen
  4. Chenyi Wu
  5. Christian Pansch
  6. Felix Mittermayer
  7. Fredrik Jutfelt
  8. Henrik Pavia
  9. Hitoshi Araki
  10. Irene Kalchhauser
  11. Kai Lohbeck
  12. Lars Bosshard 1
  13. Lars Bosshard 2
  14. Leon Green Ekelin
  15. Silva Uusi-Heikkilä
  16. Simon Cragg
  17. Xiaoxu Li

Borer culturing and transcriptomic studies (to cover capabilities, experiments, data sets and bioinformatic challenges)

Amaia Green Etxabe
Institute of Marine Sciences, Portsmouth, UK

Some crustacean species are able to consume wood as their primary food source without the aid of resident gut-flora. These crustaceans must have an endogenous suite of enzymes, produced in the hepatopancreas, that work synergistically to break down this recalcitrant lignocellulose complex. Comparing the hepatopancreatic transcriptomes of wood boring crustaceans to those of closely related algal feeding relatives promises to identify the molecular differences critical to the evolution of a lignocellulosic degrading capacity. This involves identifying possible gene duplication events by assessing the number of distinct gene orthologues, alterations in alternative splicing patterns, orthologous gene sequences and differences in gene expression levels.


Fisheries-induced evolution and its ecological feedbacks

Anna Kuparinen
Fisheries and Environmental Management Group (FEM), Dept Environmental Sciences, University of Helsinki, Finland

Harvesting of natural populations can lead to evolutionary changes in life histories through adaptation to altered mortality conditions and evolution driven by selection on life-history traits such as body size or growth rate. Harvested populations worldwide show trends towards lower age and size at maturation and smaller adult body size, and the magnitude of trait changes are positively correlated with harvesting intensity. From wildlife management and sustainable harvesting perspectives, it is important to understand how changes in species life histories translate to changes in population demography, ecosystem dynamics, and population and ecosystem resilience and ability to recover from low abundances. In my presentation, I will start by investigating phenotypic selection induced by fishing, associated life history trends, and reflect the expected ecological feedbacks using single- and multispecies-based projections.


Structure and function of novel GH7 and GH9 family glycoside hydrolases

Chenyi Wu
Biophysics Laboratories, University of Portsmouth, UK

Prospecting enzymes capable of digesting lignocellulosic biomass has focused on the relatively few types of microorganisms and animals that have wood-degrading capability. Of particular interest are the GH9-family enzymes that hydrolyze internal glycosidic bonds, and the GH7 cellobiohydrolase enzymes that processively hydrolyze cellulose polymers to cellobiose. We are exploring the rich resource of endogenous lignocellulose-degrading enzymes from the marine environment. Unlike animals such as termites that rely on symbionts to produce digestive enzymes, the marine crustacean Limnoria quadripunctata has a sterile gut and produces all the necessary enzymatic machinery to efficiently digest these challenging substrates. A detailed characterization of Limnoria GH7 revealed remarkable properties unseen in the well-studied fungal GH7 from Hypocrea jecorina.


The significance of summer Heat Waves - insights from a benthocosms community study

Christian Pansch
GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany

Christian Pansch, Yvonne Sawall, Martin Wahl 


Can Cod Cope - Epigenetic and Transgenerational Response to Ocean Acidification.

Felix Mittermayer

Mittermayer F.; Stiasny M. ; Clemmesen C. & Reusch TBH.
GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany

Evidence is accumulating that early life stages of fishes, for example Atlantic cod (Gadus morhua L.) are particularly vulnerable to increasing CO2 concentrations in the oceans also dubbed ocean acidification. Effects include increased mortalities and changed growth patterns, which are likely to have detrimental effects on the populations. Yet, results so far only address the direct effects of ocean acidification on larvae within a single generation while transgenerational effects have rarely been studied. Exceptions are tropical reef fish where transgenerational exposure has the potential to buffer detrimental effects of climate change. Regardless of the study species, the number of studies addressing the molecular mechanisms of transgenerational inheritance are even fewer. Of particular interest are the epigenetic mechanisms as they can potentially alter transcriptional regulation, for example through chromatin remodeling, small interfering RNA (siRNA) and DNA methylation. Such altered gene expression, in turn, may be the major mechanism by which adverse stress effects can be mitigated.

This poster presents an experimental setup and workflow to investigate transgenerational epigenetic effects and mechanisms, in particular changes of methylation patterns, on Atlantic cod under end-of-century pCO2 levels.


Evolution and mechanisms of thermal tolerance - a laboratory selection experiment in zebrafish

Fredrik Jutfelt
Department of Biology,
Norwegian University of Science and Technology (NTNU), Norway

Thermal biology is the study of how temperature shapes organisms and ecosystems. However, two central questions of thermal biology remain unresolved:

  1. What limits the thermal tolerance of ectothermic animals?
  2. How rapid is the evolution of thermal tolerance in a population?

I will attempt to answer these questions using multi-generation artificial selection experiments in wild-caught zebrafish (Danio rerio), and subsequent investigations of the thermal physiology of the adapted populations. My aims are: to identify the limiting physiological mechanisms underlying thermal tolerance, and to estimate the heritability and evolutionary rate of upper thermal tolerance. However, before starting this large experiment I would like to hear the experience and suggestions from the CeMEB assembly. Any thoughts on experimental design, follow-up experiments and suggestions for collaborations are welcome.


Fish stocking as a solution for local stock enhancement?

Hitoshi Araki
Professor, Animal Ecology Lab, Research Faculty of Agriculture, Hokkaido University, Japan

Fish stocking is widely accepted in fisheries as a solution for local stock enhancement. However, the demographic effect of fish stocking in the wild is often not evaluated. In addition, released fish from hatcheries can potentially have a negative impact onto genetic structure of the local populations. To date, however, little is known about the interaction between local fish stock and hatchery stock in the wild. In this presentation, I will briefly summarize my past studies on reproductive success of hatchery-reared fish in the wild and of their wild-born offspring. I also discuss theoretical predictions of the outcome from recurrent fish stocking, and future directions on wild fish survey.


Evolution and adaptation of a globally invasive fish

Irene Kalchhauser

Irene Adrian-Kalchhauser, Patricia Burkhardt-Holm
Department of Environmental Sciences, University of Basel, Switzerland

Invasive species represent genuine species success stories. They are on top of evolution: adaptive, highly reproductive, frugal, able to rebound quickly, with high dispersing abilities.
Therefore, invasive species offer unique opportunities for evolutionary biology research to investigate factors promoting evolutionary success.

I am using the round goby as invasive model organism. Round gobies are small, benthic fish with a characteristic pelvic fin and black fin dot. They have spread from the Ponto-Caspian region in Europe and North America, colonize freshwater and brackish habitats alike, and reach staggering densities within a few reproductive seasons.

I will describe two ongoing experiments on the evolutionary and adaptive potential of round goby. In one approach, I am investigating genetic processes at the invasion front of round goby in Switzerland. Using RAD-Seq, I will determine the success and failure of individual alleles during the early colonization process in the field. In another approach, I am investigating which maternal RNAs are passed from mother to offspring in the field. I have collected 1-cell embryos during the 2015 spawning season and am currently analyzing the transcriptome.


Assessing evolutionary adaptation to climate change in marine phytoplankton

Kai T. Lohbeck
Department of Marine Sciences, University of Gothenburg, Sweden

Global climate change is accompanied by acidification and warming of the surface ocean, rapid environmental changes that may have substantial consequences for ecosystem functioning. Our present understanding of the biological consequences of these changes is primarily based on short-term experiments while the potential for evolutionary adaptation is only slowly gaining attention. Fast reproducing planktonic organisms, such as phytoplankton, are particularly good candidates to study evolutionary adaptation to rapid environmental change. In my previous work I used experimental evolution to investigate the adaptive potential of the globally important coccolithophore Emiliania huxleyi to ocean acidification and warming. Experimental evolution is a valuable tool to study the potential for adaptation and the underlying mechanisms. However, adaptation observed in the laboratory has to be scrutinized in natural populations facing much more complex environmental changes. One outstanding opportunity to investigate evolutionary adaptation in natural phytoplankton populations can be found in Swedish coastal waters where cooling water discharges from nuclear power plants have resulted in well documented temperature perturbations. I plan to revive resting stages preserved in the sediments at such sites to establish clonal isolates of the common diatom Skeletonema marinoi. These isolates will be used in temperature assays to study adaptation to warming in pre- and post-power plant populations in the laboratory. To find reoccurring genetic differences in pre- and post-power plant genotypes I plan to use genome scans. In particular I want to make use of parallel genomic signatures from genotypes derived from two independent sites to identify candidate genes or genomic regions that are relevant for temperature adaptation against the noise of genetic diversity that is to be expected in natural populations.


Consequences of Spatial Expansions on Functional Genetic Diversity

Lars Bosshard

Lars Bosshard & Stephan Peischl
Institute of Ecology and Evolution, University of Bern, Switzerland

It is known that spatial expansions have had a major influence on population genetic diversity: some neutral variants can increase in frequency and spread over large areas in newly occupied territories. This is the phenomenon of gene surfing. However, selected variants can also surf and thus modify the fitness of expanding populations. We have studied this phenomenon by simulations and by analytical derivations in relatively simple models of expansions in homogeneous environments. Very generally, we find that the fitness of populations located on the expansion front decreases as a function of their distance from the origin of the expansion. The creation of this expansion load happens in 1D or 2D expansions, in case of hard or soft selection, and in presence or absence of recombination. However, the evolutionary dynamics of the expansion load differs between cases, and also depends on the level of dominance between variants.


Accumulation of Deleterious Mutation in Expanding Bacterial Populations

Lars Bosshard
Institute of Ecology and Evolution, University of Bern, Switzerland

In my presentation, I will show experimental evidence that expansion load indeed occurs in bacterial populations. We performed 40-day range expansion experiments on agar plates, corresponding to approximately 1700 generations of continuous range expansion. We compared bacteria from the expanding populations to a lower mutation strain but also to a strain that evolved in a large, well-mixed population (chemostat). In agreement with theoretical predictions we find (i) that the expansion speed of high mutation lines decreases over time, (ii) that individuals from expanding populations carry more mutations than individuals that evolved in large, well-mixed populations, (iii) evidence for an absence of selection against deleterious mutations on agar plates but not in chemostat, and (iv) high mutation line individuals from expanding populations are outcompeted by the ancestral strain both on agar plates and in chemostat, indicating that their fitness has indeed decreased during the range expansion.
 


Is sperm performance locally adapted in the invasive round goby?

Leon Green Ekelin
Department of Biological and Environmental Sciences, University of Gothenburg, Sweden

Charlotta Kvarnemo, Jonathan Havenhand, Erica Leder
Department of Biological and Environmental Sciences, University of Gothenburg

The round goby (Neogobius melanostomus), native to the Black and Caspian Seas is now an invasive species in North America and Europe with expansion ranges working their way towards saltier coastlines. In the Baltic Sea, it has been shown to rapidly differentiate genetically since the introduction 1990. Environmental effects on sensitive early life stages limit most organisms and selection is therefore likely to be strong on traits that enable survival of sperm, eggs and developing stages. Given that the round goby has already spread to salinities ranging from 0-12‰ points to an effective phenotypic plasticity or strong ability to adapt to local conditions. We aim to investigate their performance in different salinities by comparing expanding populations and traits related to fecundity and fertilization. This will be done using motility filming, assessing DNA damage and survival of sperm together with population genetics. Here we present sperm performance data from the localities sampled, and an introduction to our project at large.


The Molecular Mechanisms and Reversibility of Fisheries-Induced Evolution

Silva Uusi-Heikkilä
Department of Biology, University of Turku, Finland

Silva Uusi-Heikkilä1, Tiina Sävilammi1, Erica Leder1, Robert Arlinghaus2 and Craig R. Primmer1
1 Division of Genetics and Physiology, Department of Biology, University of Turku, Finland
2 Leigniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany

Large shifts in phenotypic traits have been observed in exploited fish populations, which have not always fully recovered despite fishing has been ceased. Fisheries-induced evolution (FIE) can explain these potentially slowly reversible changes. However, detecting signals of FIE and its reversibility has proven difficult. We study the molecular mechanisms of FIE by sequencing the transcriptome of experimental fish (wild-origin zebrafish, Danio rerio) that have been harvested size selectively for five generations and then maintained under no-selection for six generations. We studied 1) what are the molecular mechanisms underlying FIE, 2) does intensive size-selective harvesting affect gene expression variation, and 3) whether the genetic changes caused by size-selective harvesting are reversible. Our results show that five generations of size selection induced substantial changes in gene expression. In addition to expression evolution, we found signals of sequence evolution: a large number of SNPs were candidates for being subject to selection. We further show that size-selective harvesting generally reduced gene expression variation. Harvest-induced changes in gene expression were eroded after cessation of size-selective harvesting but there was no sign of full genetic recovery either at the gene expression or at the sequence level. Similarly, gene expression variation and sequence-level variation did not rebound back to the initial levels.


Enzyme discovery in marine wood borers

Simon Cragg
School of Biological Sciences, University of Portsmouth, UK

Lignocellulosic feedstocks are used for generation of 2nd generation biofuels. These woody materials are recalcitrant to enzymatic breakdown, so prospecting for novel enzymes and breakdown mechanisms offers the potential for innovation in fuel production processes. This presentation provides examples of the prospecting process. Marine wood borers, particularly members of the isopod Limnoriidae and the bivalve Teredinidae are promising sources of such enzymes and mechanisms. We have used gene identification and phylogenetic analysis to inform further searching and to provide sequences for heterologous gene expression. Soluble proteins have been expressed and crystallization conditions have been optimised. High-resolution protein structure have been generated from X-ray diffraction data collected at the Diamond Light Source. Comparisons of related protein structures and in-silico simulations have generated valuable insights into protein function.


Doubled Haploid Pacific Oysters – Techniques and Potential Applications

Xiaoxu Li
South Australian Research and Development Institute (SARDI), Australia

Doubled haploid is a genotype formed when haploid cells (n) undergo chromosome doubling (2n), resulting in complete homozygous individuals in one generation. The doubled haploid technique has been used in plant breeding programs for several decades and is currently the method of choice in all plant species where the technique is sufficiently developed.

Doubled haploids have also been used extensively in fundamental genetic studies, such as gene mapping and genomics.

Doubled haploid Pacific oysters could be produced by fertilizing eggs with genetically denatured sperm and then doubling the chromosome number of resultant haploid “zygotes” at the first mitotic division. However, to apply the doubled haploid technique in Pacific oyster genetic improvement programs, effective and efficient methods for genetic load confirmation in potential female broodstock and for establishment of homozygous families for F1 hybrid commercialization need to be validated or developed.

Page Manager: Eva Marie Rödström|Last update: 10/2/2015
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