Two special courses this spring

Arnar Pálsson, 17/02/2023
The biology programme offers two short courses this spring.
2 ECTS 7-DAY SUMMER COURSE

This 7-day workshop will be based on the recently published Conservation and the Genomics of Populations (3rd edition, Allendorf et al. 2022). This established book provides a comprehensive overview of the essential background, concepts, and tools required to understand how genetics and genomics can be used to conserve species, reduce the threat of extinction, and manage species of ecological or commercial importance. Allendorf will present the subject of the book over three days and then students will prepare and present a short lecture of their project or article. New genomic techniques and statistical analyses are crucial tools for the conservation geneticist. This workshop will provide an essential toolkit grounded in population genetics theory, coupled with basic and applied research examples from plants, animals, and microbes. The workshop will examine genetic and phenotypic variation in natural populations, the principles and mechanisms of evolutionary change, evolutionary response to anthropogenic change, and applications in conservation and management. Topics 1. Introduction 2. Genomic variation in populations 3. Hardy-Weinberg principle 4. Genetic drift & effective population size 5. Natural selection 6. Mutation 7. Gene flow & population structure 8. Multiple loci 9. Hybridization 10. Inbreeding depression 11. Units of conservation 12. Demography and extinction 13. Exploited populations 14. Climate change 15. Genetic monitoring

Learning Outcomes:

At the end of the course, a students should be able to:

  • to describe the background and the concepts of population genetics with relation to conservation
  • to describe the main genetic and genomic methods which can be applied in species conservation
  • to describe applications of genetics and genomics in management of ecological and commercial importance.
For more info contact

Snæbjörn Pálsson
2 ECT 5-DAY SUMMER SCHOOL
The mesopelagic zone (between 200-1000m depth) is the habitat of the largest fish biomass in the ocean.
Mesopelagic fish likely hold a key role in global climate change by participating in the largest migration in the animal kingdom, transporting and storing carbon into the deep sea.

Credit: Leif Grimsmo, SINTEF Ocean

About the course
The SUMMER (Sustainable Management of Mesopelagic Resources, 2019-2024) EU project aims to evaluate if and how mesopelagic resources can be sustainably exploited.
To share the knowledge of the mesopelagic zone, experts from the SUMMER project have arranged a 5-day summer school course for 2 ECT credits, with the Marine and Freshwater Research Institute and the University of Iceland, in Iceland May 22nd – May 26th 2023.
The course will feature lectures from world-leading experts on mesopelagic research, engaging discussions, as well as hands-on laboratory work on mesopelagic fishes – in addition to the dissection of a marine mammal, apex predator of mesopelagic fish.
After completing the course
Students will be familiar with:
• Biology and Ecology of the Mesopelagic Zone
• Taxonomy and Diversity of Mesopelagic Fish
• Mesopelagic Fisheries (Economy, Governance,
Technology)
• Dissection of Mesopelagic Fish and Mammals
Students will develop valuable knowledge of one of the most understudied ecosystems in the world’s oceans, meet worldwide leaders in mesopelagic research, and study in an international group.
Students will also get to experience Reykjavik, the capital of Iceland in May – during a wonderfully bright spring.
The course itself is free for participatnts, but travel expenses (food, lodgings, and transport) must be covered individually.
International students are encouraged to apply, and housing is available on the university campus.
For more information
Website: www.summerh2020.eu
Email: hrandhawa@hi.is

The mesopelagic zone - 5 day course in May.

Arnar Pálsson, 20/01/2023
2 ECT 5-DAY SUMMER SCHOOL COURSE
The mesopelagic zone (between 200-1000m depth) is the habitat of the largest fish biomass in the ocean.
Mesopelagic fish likely hold a key role in global climate change by participating in the largest migration in the animal kingdom, transporting and storing carbon into the deep sea.

Credit: Leif Grimsmo, SINTEF Ocean

About the course
The SUMMER (Sustainable Management of Mesopelagic Resources, 2019-2024) EU project aims to evaluate if and how mesopelagic resources can be sustainably exploited.
To share the knowledge of the mesopelagic zone, experts from the SUMMER project have arranged a 5-day summer school course for 2 ECT credits, with the Marine and Freshwater Research Institute and the University of Iceland, in Iceland May 22nd – May 26th 2023.
The course will feature lectures from world-leading experts on mesopelagic research, engaging discussions, as well as hands-on laboratory work on mesopelagic fishes – in addition to the dissection of a marine mammal, apex predator of mesopelagic fish.
After completing the course
Students will be familiar with:
• Biology and Ecology of the Mesopelagic Zone
• Taxonomy and Diversity of Mesopelagic Fish
• Mesopelagic Fisheries (Economy, Governance,
Technology)
• Dissection of Mesopelagic Fish and Mammals
Students will develop valuable knowledge of one of the most understudied ecosystems in the world’s oceans, meet worldwide leaders in mesopelagic research, and study in an international group.
Students will also get to experience Reykjavik, the capital of Iceland in May – during a wonderfully bright spring.
The course itself is free for participatnts, but travel expenses (food, lodgings, and transport) must be covered individually.
International students are encouraged to apply, and housing is available on the university campus.
For more information
Website: www.summerh2020.eu
Email: hrandhawa@hi.is

Manuscript on craniofacial variation in sympatric ecomorphs of Arctic charr

Arnar Pálsson, 09/11/2022

This darling is nearly ready for submission. Very cool results from a study led by Guðbjörg Ósk Jónsdóttir and Sarah Steele, based on pioneering work by Finnur Ingimarsson and Sigurður S. Snorrason.

Diversity in the internal functional feeding elements of sympatric morphs of Arctic charr (Salvelinus alpinus) 

Jónsdóttir, G.Ó., von Elm, L-M, Ingimarsson, F., Tersigni, S., Snorrason, S.S, Pálsson, A. and Steele, S.E. 

One cool figure from the manuscript, showing shape variation in bones in the four sympatric morphs of Arctic charr in Lake Þingvallavatn.

Shape variation in the articular angular, part of the lower jaw, PCA of individuals and the first two axes of shape variation (after size correction).

Colour coding follows previous publications, large benthic (Green), small benthic (blue), planktivorous (red) and piscivorous charr (purple).

The morphs are genetically separable, with a twist...

Jóhannes Guðbrandsson, Kalina H. Kapralova, Sigríður R. Franzdóttir, Þóra Margrét Bergsveinsdóttir, Völundur Hafstað, Zophonías O. Jónsson, Sigurður S. Snorrason, Arnar Pálsson. 2019. Extensive genetic differentiation between recently evolved sympatric Arctic charr morphs Ecology and Evolution.  9:10964–10983. doi: 10.1002/ece3.5516.

A novel region within a conserved domain in ATG7 emerged in vertebrates.

Arnar Pálsson, 24/08/2022

A nice paper by Valgerður Hjaltalín and colleagues was accepted to Autophagy Reports. She worked on this during covid, with some help from us and others. Then added a nice experimental data to the manuscript during revisions. More on this as it emerges on the journal website.

A novel region within a conserved domain in ATG7 emerged in vertebrates.

Valgerdur J. Hjaltalin, Vivian Pogenberg, Kévin J. A. Ostacolo, Arnar Pálsson, Margrét Helga Ogmundsdottir

DNA methylation differences during development distinguish sympatric morphs of Arctic charr (Salvelinus alpinus)

Arnar Pálsson, 25/07/2022
DNA methylation differences during development distinguish sympatric morphs of Arctic charr (Salvelinus alpinus)
Accepted in Molecular Ecology, first published: 18 July 2022

Changes in DNA methylation in specific coding or non-coding regions can influence development and potentially divergence in traits within species and groups. While the impact of epigenetic variation on developmental pathways associated with evolutionary divergence is the focus of intense investigation, few studies have looked at recently diverged systems. Phenotypic diversity between closely related populations of Arctic charr (Salvelinus alpinus), which diverged within the last 10 000 years, offers an interesting ecological model to address such effects. Using bisulfite sequencing, we studied general DNA methylation patterns during development in the four sympatric morphs of Arctic charr from Lake Thingvallavatn. The data revealed strong differences between developmental timepoints and between morphs (mainly along the benthic – limnetic axis), both at single CpG sites and in 1,000bp-regions. Genes located close to differentially methylated CpG sites were involved in nucleosome assembly, regulation of osteoclast differentiation, and cell-matrix adhesion. Differentially methylated regions were enriched in tRNA and rRNA sequences, and half of them were located close to transcription start sites. The expression of 14 genes showing methylation differences over time or between morphs was further investigated by qPCR and nine of these were found to be differentially expressed between morphs. Four genes (ARHGEF37-like, H3-like, MPP3 and MEGF9) showed a correlation between methylation and expression. Lastly, histone gene clusters displayed interesting methylation differences between timepoints and morphs, as well as intragenic methylation variation. The results presented here provide a motivation for further studies on the contribution of epigenetic traits, such as DNA methylation, to phenotypic diversity and developmental mechanisms.

Acceptable ants and Atg7 on a run

Arnar Pálsson, 13/06/2022

European fire ants found in Iceland. / Evrópskir eldmaurar (Myrmica rubra) á Íslandi. Marco Mancini, Andreas Guðmundsson og Arnar Pálsson. Accepted by the Icelandic naturalist (Náttúrufræðingurinn).

Phylogenetic analyses revealed emergence in vertebrates of a novel region within a conserved domain in ATG7. Valgerdur J. Hjaltalin, Vivian Pogenberg, Arnar Pálsson, Margrét Helga Ogmundsdottir. (being revised).

DNA methylation differences during development distinguish sympatric morphs of Arctic charr

Arnar Pálsson, 25/03/2022

DNA methylation differences during development distinguish sympatric morphs of Arctic charr (Salvelinus alpinus). Sebastien Matlosz, Benjamin Sigurgeirsson, Sigrídur Rut Franzdóttir, Arnar Pálsson, Zophonías O. Jónsson. (not on bioRxiv, second revision sent in).

Sebastien sent the revised manuscript again. Must say I am very excited about this study and its implications.

From the abstract.

  • The data revealed strong differences between developmental timepoints and between morphs (mainly along the benthic – limnetic axis), both at single CpG sites and in 1000bp-regions. Genes located close to differentially methylated CpG sites were involved in nucleosome assembly, TGF-β regulation, and cell matrix adhesion.

Contributions to the Icebio2021

Arnar Pálsson, 22/12/2021

The lab had several contributions to the biannual Biology in Iceland conference. These were, in no particular order.

Talks

Experimental tests of unicoloniality in Hypoponera species (Hymenoptera: Formicidae) living underground Reykjavík
Marco Mancini, Andreas Guðmundsson, Mariana Lucia Tamayo, James K. Wetterer, Arnar Pálsson

Diversity in the internal functional feeding elements of Arctic charr, Salvelinus alpinus, morphs in Lake Thingvallavatn, Iceland.
Guðbjörg Ósk Jónsdóttir, Finnur Ingimarsson, Sigurður Sveinn Snorrason, Sarah Elizabeth Steeleand Arnar Pálsson

Correspondence of morphological divergence across genotypes in response to diet follows evolutionary divergence of ecologically specialized morphs
Sarah E. Steele, Arnar Pálsson

DNA methylation patterns separate sympatric morphs of Arctic charr
Sébastien Matlosz, Benjamín Sigurgeirsson, Arnar Pálsson, Sigríður R. Franzdóttir, Zophonías O. Jónsson

New wine in old bottles: Geometric morphometric analysis revealed shape and allometric variation among sympatric Arctic charr morphs in Lake Thingvallavatn
Han Xiao, Arnar Pálsson, Sigurður S. Snorrason, Zophonías O. Jónsson

Transcriptional rewiring following compensatory selection of major mutations
Baldur Kristjánsson, Dagný Á. Rúnarsdóttir, Sudarshan Chari, Ian Dworkin, Arnar Pálsson

Dragging skeletons on wings: the effects of strong selection on transcriptional landscapes
Arnar Pálsson, Baldur Kristjánsson, Lea Jerman Plesec, Dagný Ásta Rúnarsdóttir

 

Posters

Food availability of juvenile Atlantic salmon (Salmo salar) in rivers of Northeast Iceland Sum Yi Lai, Jón S. Ólafsson, Arnar Pálsson, James Rosindell, Guðni Guðbergsson, Ingi Rúnar Jónsson, Hlynur Bárðarson

Population genetics of stream populations of Arctic charr in North Iceland Sabrina Carli , Sabrina Carli, Irem Dogruoglu, Han Xiao, Marcos Lagunas, Dagny Ásta Rúnarsdóttir, Stefán Óli Steingrímsson, Sarah E. Steele, Arnar Pálsson

A region of ATG7 evolved in vertebrates and might account for a new function Valgerður Jakobína Hjaltalín, Margrét Helga Ögmundsdóttir, Arnar Pálsson

First results from scanning of charr juveniles

Arnar Pálsson, 06/09/2021

We have started a collaboration with Benedikt Hallgrimsson and his colleagues at University of Calgary, Marta Vidal-Garcia and Avrille Aiello.

They are scanning one year old Arctic charr that Sarah Steele raised in her plasticity experiment. That study focused on comparing morphological differences and plastic responses between derived and ancestral populations of charr, to understand differences in growth, allometric changes in shape and inheritance of these traits.

The pilot project with the Hallgrimsson lab focuses on comparing three morphs, the anadromous charr from Fljota (putative ancestral morph) and two derived morphs from Lake Thingvallavatn, the Large Benthic and Planktivorous charr. They were all raised on the same diet, and are similar in size. First scans from Avrille and Marta, of an LB individual, are shown below.

The top figure is lateral view (with an angle slightly from the front) and the lower figure is a view from the top of the head (first vertebrae can be seen on the right).

The fishes were about 1 year old when killed and frozen. Fixed in 10% NPF for 10 days, prior to CT scanning.

In this phase of the project we will scan 20 fishes per morph, and characterize the diversity in shape of the feeding related bones, snout area and the cranium.

And hopefully be able to scan the other treatment, wild fishes and progeny from crosses in the future if funding becomes available.

Contributions to the Icelandic Ecology Conference

Arnar Pálsson, 24/04/2021

Several members of our lab and students we help supervise contributed to the Icelandic Ecology Conference in April 2021.

 

Lasius niger ant dragging a larvae. Picture taken by Marco Mancini.

Marco Mancini - Unveiling the myrmecofauna (Hymenoptera: Formicidae) of Iceland. A survey of invasive ant species diversity and distribution

Arnar Pálsson - Unleashing of cryptic genetic variation by environmental challenges and genetic assimilation studied at level of gene expression

Sarah Steele - Correspondence of morphological divergence across genotypes in response to diet follows evolutionary divergence of ecologically specialized morphs

Sebastien Matlosz - DNA methylation in Arctic charr: Epigenetics to explain resource polymorphism.

Link to abstract book.