Sigridur Helga Thorbjarnardottir passed away late 2015. She was my main advisor during my master studies at the University of Iceland. The other advisor was Gudmundur Eggertsson. Sigridur was also the head of the Icelandic biological society in the eighties. The eulogy in icelandic appeared in the local paper and on the website of the society.
In the beginning of November the Icelandic biological society and associates organized a conference on biological research in Iceland. This event has run biannually since 2009, and before that it was organized by the society and the Institute of Biology at the University of Iceland (every 5 years).
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.
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
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.
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.
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 'Bones in motion: Ontogeny of craniofacial development in sympatric Arctic charr morphs - accepted in Developmental dynamics'»
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 'Hvað þýðir það að erfðavísar séu ónýtir og hafa þeir áhrif á svipfar?'»
