Published: Differential expression of the aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr

Posted on: 28/09/2015 by Arnar Pálsson

Differential expression of the aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr. Ahi EP, Steinhäuser SS, Pálsson A, Franzdóttir SR, Snorrason SS, Maier VH, Jónsson ZO. Evodevo. 2015 Sep 16;6:27. doi: 10.1186/s13227-015-0022-6.

BACKGROUND:

The developmental basis of craniofacial morphology hinges on interactions of numerous signalling systems. Extensive craniofacial variation in the polymorphic Arctic charr, a member of the salmonid family, from Lake Thingvallavatn (Iceland), offers opportunities to find and study such signalling pathways and their key regulators, thereby shedding light on the developmental pathways, and the genetics of trophic divergence.

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Posted in Publications

(Icelandic) Minning um taugalíffræðingin Oliver Sacks

Posted on: 28/09/2015 by Arnar Pálsson

Sorry, this entry is only available in Icelandic.

Posted in General biology

Accepted: Differential expression of the Aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr

Posted on: 05/09/2015 by Arnar Pálsson

Just accepted in EvoDevo

Differential expression of the Aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr
Ehsan Pashay Ahi; Sophie S Steinhäuser; Arnar Pálsson; Sigrídur Rut Franzdóttir; Sigurdur S Snorrason; Valerie Helene Maier, Zophonías O Jónsson

Posted in Publications

Mitf is a master regulator of the v-ATPase, forming a control module for cellular homeostasis with v-ATPase and TORC1.

Posted on: 05/08/2015 by Arnar Pálsson
Im quite proud of helping with evolutionary and statistical analyses for a recent paper from Francesca Pignoni and colleagues.
Zhang T, Zhou Q, Ogmundsdottir MH, Möller K, Siddaway R, Larue L, Hsing M, Kong SW, Goding CR, Palsson A, Steingrimsson E, Pignoni F. Mitf is a master regulator of the v-ATPase, forming a control module for cellular homeostasis with v-ATPase and TORC1. J Cell Sci. 2015 Aug 1;128(15):2938-50. doi: 10.1242/jcs.173807. Epub 2015 Jun 19.

Abstract

The v-ATPase is a fundamental eukaryotic enzyme that is central to cellular homeostasis. Although its impact on key metabolic regulators such as TORC1 is well documented, our knowledge of mechanisms that regulate v-ATPase activity is limited. Here, we report that the Drosophila transcription factor Mitf is a master regulator of this holoenzyme. Mitf directly controls transcription of all 15 v-ATPase components through M-box cis-sites and this coordinated regulation affects holoenzyme activity in vivo. In addition, through the v-ATPase, Mitf promotes the activity of TORC1, which in turn negatively regulates Mitf. We provide evidence that Mitf, v-ATPase and TORC1 form a negative regulatory loop that maintains each of these important metabolic regulators in relative balance. Interestingly, direct regulation of v-ATPase genes by human MITF also occurs in cells of the melanocytic lineage, showing mechanistic conservation in the regulation of the v-ATPase by MITF family proteins in fly and mammals. Collectively, this evidence points to an ancient module comprising Mitf, v-ATPase and TORC1 that serves as a dynamic modulator of metabolism for cellular homeostasis.

Posted in Publications

Post doc available: The role of transcriptional and regulatory changes during compensatory evolution

Posted on: 02/07/2015 by Arnar Pálsson

Which principles influence the rewiring and tuning of gene regulatory networks? How do those network react to genetic perturbations? We are seeking a post-doc to tackle those and related questions in project utilizing populations of Drosophila (fruit flies) that have undergone compensatory adaptation using experimental evolution and artificial selection. The project involves the analysis of tissue specific RNA-seq and numerical analyses. The ideal candidate is strong in evolutionary genetics, statistical and bioinformatic analyses and with capable hands for molecular biology. Excellent communication skills, main focus on writing, are required, as is a solid publication record. The candidate will be encouraged (and given time) to develop their own research program.

This project is built on hypothesis that sprung out of work on indel polymorphism in the even skipped stripes 3+7 enhancer.

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Posted in Uncategorized

Bones in motion: Ontogeny of craniofacial development in sympatric Arctic charr morphs - accepted in Developmental dynamics

Posted on: 08/06/2015 by Arnar Pálsson

Bones in motion: Ontogeny of craniofacial development in sympatric Arctic charr morphs

Kalina H. Kapralova, Zophonías O. Jónsson, Arnar Palsson, Sigrídur Rut Franzdóttir, Soizic Le Deuff, Bjarni K. Kristjanson, Sigurður S. Snorrason.

Background: The impressive diversity in the feeding apparatus often seen among related fish species clearly reflects differences in feeding modes and habitat utilization. Such variation can also be found within species. One example of such intraspecific diversity is the Arctic charr in Lake Thingvallavatn, where four distinct morphs coexist: two limnetic with evenly protruding jaws and two benthic with subterminal lower jaws. We used these recently evolved morphs to study the role of ontogenetic variation for craniofacial diversity. Continue reading →

Posted in Publications

Hvað þýðir það að erfðavísar séu ónýtir og hafa þeir áhrif á svipfar?

Posted on: 13/05/2015 by Arnar Pálsson

Hvað þýðir það að erfðavísar séu ónýtir og hafa þeir áhrif á svipfar? Gen (erfðavísar) eru mikilvægasti hluti erfðaefnisins. Erfðaefnið DNA eru tvíþátta þræðir sem mynda litningana. Við manneskjurnar fáum eitt sett af litningum frá móður og eitt sett frá föður. Því höfum við tvö heil eintök af flestum okkar genum - eitt frá hvoru foreldri. Það er kallað að vera tvílitna. Algengast er að dýr séu tvílitna en bakteríur eru flestar einlitna. Continue reading →

Posted in Vísindavefur - svör

The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus) morphs - sent to F1000research

Posted on: 17/04/2015 by Arnar Pálsson

Lets hope we are lucky third time around. Now we send this little baby to F1000research. The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus) morphs Johannes Gudbrandsson*, Ehsan P. Ahi, Sigridur R. Franzdottir, Kalina. H. Kapralova, Bjarni K. Kristjansson#, S. Sophie Steinhaeuser, Isak M. Johannesson, Valerie H. Maier, Sigurdur S. Snorrason, Zophonias O. Jonsson, and Arnar Palsson* Institute of Life and Environmental Sciences, University of Iceland, 101 Reykjavik, Iceland #Holar University College, 551 Saudarkrokur, Iceland *Corresponding authors.

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Posted in Publications

Vísindavefur: Hvað eru HeLa-frumur?

Posted on: 26/03/2015 by Arnar Pálsson

Hvað eru HeLa-frumur? Arnar Pálsson. „Hvað eru HeLa-frumur?“. Vísindavefurinn 9.3.2015. http://visindavefur.is/?id=69338. Árið 1951 innritaðist rúmlega þrítug kona, Henrietta Lacks (1920–1951), á John Hopkins-spítalann í Baltimore sem á þessum tíma var einn fárra spítala sem meðhöndluðu blökkufólk. Ástæða spítalavistarinnar var hnútur í kviðarholi sem læknar greindu síðan sem krabbamein á leginu. Því miður dugði meðferð ekki til að bjarga lífi hennar en hún lést október þetta sama ár. Seinna kom í ljós að orsökin var HPV-sýking sem er ein algengasta orsök leghálskrabbameins. Á meðan á meðferð Henríettu stóð voru frumur fjarlægðar úr æxlinu og setti vísindamaðurinn George Gey (1899-1970) þær í rækt, að Henríettu forspurðri.

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Posted in Vísindavefur - svör

Submitted to Plos One: The developmental transcriptome of contrasting Arctic charr (Salvelinus alpinus) morphs

Posted on: 24/02/2015 by Arnar Pálsson

We just sent this manuscript to PLoS One, after G3 decided they did not like it. (Main sticking point is that they wanted de novo assembly - but we argued it was not a good idea with the 36bp non paired end reads) At any rate, I like PLoS One, and would like to publish one paper there a year...

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Posted in Publications