(Icelandic) Stökkbreytast veirur hraðar en flóknar lífverur?
covid 19 genetics and evolution background for Icelandic public.
Plastic charr at Oikos 2020
Sarah E. Steele presented her work in the Oikos meeting last week.
Mechanisms and axes of developmental plasticity and evolutionary divergence. Sarah Steele, Dagný Runarsdottir, Bjarni Kristjansson, Skuli Skulason, Prof Camille Leblanc, Sigridur R. Franzdottir, Zophonias Jonsson, Sigurdur Snorrason, Arnar Palsson.
Why are some species plastic and capable of rapid phenotypic diversification and polymorphism, while others are less flexible at the phenotype level and evolve more slowly? This question has puzzled geneticist and students of evolution for over a century, but new technologies have made it addressable. Here we set out to investigate the developmental and genetic basis of plasticity and polymorphism, applying experimental and molecular methods on the extremely diverse salmonid, Arctic charr (Salvelinus alpinus). Arctic charr has, in about 10,000 years following the ice age glacier retreat, invaded and adapted to diverse habitats, and in the process small benthic forms evolved in dozens of locations. Arctic charr is phenotypically very heterogeneous, to the extent that morphotypes were originally classified as distinct species, but also show high levels of phenotypic plasticity. We use a combination of genetic crosses, geometric morphometrics and next generation sequencing to characterize the plastic response to benthic or limnetic food. We compared wild stocks and their hybrids, reared in the laboratory, after hatching and while the juveniles are taking food. The results illuminate how we understand of the relationship of ecologically induced developmental plasticity and evolution of ecological specializations.
Marion Dellinger also presented data on behavioral phenotypes of the fishes from this experiment.
Tell me how you eat, I'll tell you who you are: how does feeding modalities affect personality distribution in the Arctic charr (Salvelinus alpinus)?
The Icelandic biology conference 2019
Late last year the lab took part in the Icelandic biology conference. The conference is biannual, and the largest aggregation of biological researchers in Iceland.
Our lab contributed several works to the meeting, and Im very proud of the students for their contributions.
Here is a list of the projects that they presented:
Can you save a mutant? Expressional rescue of 3 major wing defects in Drosophila melanogaster Baldur Kristjánsson, Dagný Á. Rúnarsdóttir, Sudarshan Chari, Ian Dworkin, Arnar Pálsson
Waddingtons landscapes explored: Expression changes associated with genetic assimilation of crossveinless phenotypes Dagný Ásta Rúnarsdóttir, Baldur Kristjánsson, Sarah Marzec, Ian Dworkin, Arnar Pálsson
Study of the genetic and developmental basis of phenotypic differences between sympatric Arctic charr (Salvelinus alpinus) morphs Nahal Eskafi, Alexander Guðjónsson, Sylvain Moinard, Lea J. Plesec, Sigurður S. Snorrason, Zophonias O. Jonsson, Arnar Palsson, Sigríður Rut Franzdóttir
Differential expression of transcription factors between Arctic charr morphsLea Jerman Plesec, Alexander Guðjónsson, Sébastien Matlosz, Jóhannes Guðbrandsson, Arnar Pálsson, Sigríður Rut Franzdóttir, Zophonías O. Jónsson
Videos from conference of Bioethics of clinical innovation and unproven methods, Copenhagen, 9 April 2019
Bioethics of clinical innovation and unproven methods, Copenhagen, 9 April 2019
Conference organized by the Nordic Committee on Bioethics in collaboration with Centre for Legal Studies in Welfare and Market at the University of Copenhagen. The central questions were:
How are clinical innovations and unproven methods developed and introduced in western Nordic health-care systems?
What is the legal and regulatory environment concerning unproven methods in medicine?
What ethical principles should guide work on emerging treatments and experimentation in hospitals?
These are questions that were addressed in the NCBio-conference in Copenhagen.
Videos of talks from the meeting on bioethics of clinical innovation and unproven methods Copenhagen, 9 April 2019 are available.
I had the great privilege of organizing this event with my colleagues in the Nordic Committee on Bioethics, in collaboration with the Centre for Legal Studies in Welfare and Market at the University of Copenhagen.
The conference is open to all interested, including medical doctors, clinical researchers, health committees in parliments, civil servants and hospital administrators.
(Icelandic) Ný grein um bleikjuafbrigðin í Þingvallavatni
Icelandic press about the paper on differentiation between the sympatric morphs in Lake Thingvallavatn.
Extensive genetic differentiation between recently evolved sympatric Arctic charr morphs
The availability of diverse ecological niches can promote adaptation of trophic specializations and related traits, as has been repeatedly observed in evolutionary radiations of freshwater fish. The role of genetics, environment and history in ecologically driven divergence and adaptation, can be studied on adaptive radiations or populations showing ecological polymorphism. Salmonids, especially the Salvelinus genus, are renowned for both phenotypic diversity and polymorphism. Arctic charr (Salvelinus alpinus) invaded Icelandic streams during the glacial retreat (about 10,000 years ago) and exhibits many instances of sympatric polymorphism. Particularly well studied are the four morphs in Lake Þingvallavatn in Iceland. The small benthic (SB), large benthic (LB), planktivorous (PL) and piscivorous (PI) charr differ in many regards, including size, form and life history traits. To investigate relatedness and genomic differentiation between morphs we identified variable sites from RNA-sequencing data from three of those morphs, and verified 22 variants in population samples. The data reveal genetic differences between the morphs, with the two benthic morphs being more similar and the PL-charr more genetically different. The markers with high differentiation map to all linkage groups, suggesting ancient and pervasive genetic separation of these three morphs. Furthermore, GO analyses suggest differences in collagen metabolism, odontogenesis and sensory systems between PL-charr and the benthic morphs. Genotyping in population samples from all four morphs confirms the genetic separation and indicates that the PI-charr are less genetically distinct than the other three morphs. The genetic separation of the other three morphs indicates certain degree of reproductive isolation. The extent of gene flow between the morphs and the nature of reproductive barriers between them remain to be elucidated.
Figure 2.
