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Joint PhD Position at the Department of Plant and Microbial Biology (IPMB) and the Department of Evolutionary Biology and Environmental Studies (EBES), University of Zurich

We are looking for a motivated student who is interested in applying molecular approaches to study questions in ecology and evolution. The project will be conducted under the joint supervision of an ecologist and molecular geneticist to investigate the role of epigenetic variation in adaptation (see project description below). Please send your application to Bernhard Schmid and Ueli Grossniklaus , including your CV and a short letter of motivation.

Population Epigenomics, Phenotypic Plasticity, and Environmental Adaptation, Bernhard Schmid (EBES), Ueli Grossniklaus (IPMB)

Despite the heritability of epigenetic variation (EV), its ecological and evolutionary significance is largely unknown and being controversially discussed [1-3]. In plants, epigenetic changes can be heritable over generations [e.g. 4,5] and occur more frequently than genetic ones [6,7]. Thus EV may allow rapid responses and has the potential to play a key role in the adaptation to environmental change. However, published results are contradictory, possibly because very small sample numbers were molecularly analyzed and experimental replication is insufficient [discussed in 3,8,9]. Over the last years, we have collected experimental data demonstrating a role for epigenetics in the response to changes in the biotic and abiotic environment using Arabidopsis thaliana as a model. We could demonstrate the selection of new, stable phenotypes in genetically uniform backgrounds in independent, replicated selection experiments, suggesting a role of EV in adaptation [see also 10]. The results, however, depended on the experimental set-up: while we found no evidence for a role in adaptation when starting with seeds from a single individual, stable phenotypes were selected when starting with seeds derived from a population. Although materials and selection scenarios used where highly diverse, this finding indicates that there is standing EV in genetically uniform populations that can be selected upon but that the rate of epigenetic change from generation to generation is too low to generate sufficient variation when starting from an individual. We will test this hypothesis in a highly replicated experiment involving 3 genotypes in 3 environments that should help to settle the controversy on the ecological and evolutionary significance of epigenetic variation.

1. Grossniklaus U, Kelly WG, Ferguson-Smith AC, Pembrey M, Lindquist S (2013) Transgenerational epigenetic inheritance: how important is it? Nat Rev Genet 14:228-235.
2. Heard E, Martienssen RA (2014) Transgenerational epigenetic inheritance: myths and mechanisms. Cell 157:95-109.
3. Hirsch S, Baumberger R, Grossniklaus U (2012) Epigenetic variation, inheritance, and selection in plant populations. Cold Spring Harb Symp Quant Biol 77:97-104.
4. Cubas P, Vincent C, Coen E (1999) An epigenetic mutation responsible for natural variation in floral symmetry. Nature 401:157-161.
5. Manning K, Tör M, Poole M, Hong Y, Thompson AJ, King GJ, Giovannoni JJ, Seymour GB (2006) A naturally occurring epigenetic mutation in a gene encoding an SBP-box transcription factor inhibits tomato fruit ripening. Nat Genet 38:948-952
6. Schmitz RJ, Schultz MD, Lewsey MG, O'Malley RC, Urich MA, Libiger O, Schork NJ, Ecker JR (2011) Transgenerational epigenetic instability is a source of novel methylation variants. Science 334:369-373.
7. Becker C, Hagmann J, Müller J, Koenig D, Stegle O, Borgwardt K, Weigel D (2011) Spontaneous epigenetic variation in the Arabidopsis thaliana methylome. Nature 480:245-249.
8. Pecinka A, Rosa M, Schikora A, Berlinger M, Hirt H, Luschnig C, Mittelsten Scheid O (2009) Transgenerational stress memory is not a general response in Arabidopsis. PLoS One 4:e5202.
9. Pecinka A, Mittelsten Scheid (2012) Stress-induced chromatin changes: a critical view on their heritability. Plant Cell Physiol 53:801-808.
10. Zuppinger-Dingley D, Schmid B, Petermann JS, Yadav V, de Deyn GB, Flynn D (2014) Selection for niche differentiation in plant communities increases biodiversity effects. Nature 515:108-111.

submitted for: Bernhard Schmid and Ueli Grossniklaus

last update: 2016-12-05

 

PhD student position in Evolutionary Ecology: on Ecology and Evolution of Cancer University of Zurich, Switzerland A PhD student position for the second phase of the URPP Evolution in Action, of 48 months duration, is available at the University of Zurich working with Prof Hanna Kokko and her international team www.kokkonuts.org. The PhD student will work to establish a proper understanding of evolutionary processes that include cancer risk as a factor that can terminate a reproductive career. This involves modelling life histories and growth schedules with cancer risk, examining trade-offs between reproduction and cancer in a wild house mouse population near Zurich (collaboration with Anna Lindholm), and collecting systematic data on long-lived animals protected from predation and parasitism (veterinary data from zoos). The PhD student will also benefit an established collaboration between Prof. Kokko's team and Prof. Carlo Maley's team at Arizona State University, as well as between Prof. Dr. Kokko and Dr. Kathleen Sprouffske. The ‘kokkonuts’ research group is also part of a Centre of Excellence in Biological Interactions, which will bring the PhD Student in contact with Universities of Helsinki and Jyväskylä in Finland Universities of Helsinki and Jyväskylä in Finland . We are a team that places a lot of emphasis on creating theoretical work that integrates well with empirical findings. The most up to date version of our current interests can be best described by the list of journal club articles that we discuss each week (www.kokkonuts.org, click on ‘journal club’). The working language in the group is English (German skills are not essential). The position is available from 01. January 2017. The target application date is 10.10.2016, but open until a suitable candidate has been found. Applicants should send a cover letter with a: Statement of their research interests, especially in relation to the journal club articles as mentioned above C.V. (including publication list) Reference letters of at least one referee should be added as a PDF. Applications should form a single PDF file and this should be sent to: hanna.kokko@ieu.uzh.ch more info (PDF, 199 KB) submitted for: Prof. Dr. Hanna Kokko