POST-DOCTORAL PROJECT
Characterization of epigenetic profiles in organisms exposed to ,ionizing radiations
2-years post-doctoral position at IRSN (France)
Background
Evaluating the effects of low dose radiation on organisms is clearly a shared challenge in research on
human and non-human species. This topic of common interest in radioecology and radiobiology is driven
by the mutual need of knowledge in human and eco-toxicology of the impact of radioactive substances on
man and the environment.
Understanding the role of primary mechanisms at the cellular and sub-cellular level when organisms are
exposed to low dose radiation will help to explain the potential consequences on physiological functions
and health at the individual and population level. Of equal importance to studying the immediate effects
of exposure to low dose radiation is the need to understand a number of related issues such as the
possible induction of long-term or transgenerational effects and the capacity of organisms to adapt to
stress.
The fact that certain species (e.g., plants and invertebrates) can evolve resistance or tolerance to
pollutants through trans-generational heritable adaptive processes is well established. On the other hand,
hereditary transfer of effects might lead to reduced fitness or increased sensitivity of offspring to stress.
Genetic and epigenetic mechanisms are thought to play a role in both cases.
Recently, the Fukushima Dai-ichi nuclear power plant (NPP) accident has impacted a large area in Japan,
including a 80-km Nord-West area contaminated from radionuclide deposition. Pale blue grass butterfly
Zizeeria maha was used as an indicator species to evaluate the environmental impact of ionizing
radiations (Hiyama et al., 2012). Mild morphological abnormalities were observed on some individuals of
adult butterflies collected in May 2011 but an increase of the severity of these abnormalities occurred in
the F1 generation, which were inherited in the F2 generation. These abnormalities may be explained by
random mutation on important genes or by epigenetic mechanisms.
These results show that the understanding of trans-generational effects induced after long-term exposure
to chronic low levels of ionizing radiations, is needed to evaluate the risk transmitted to future
generations. New data within this framework will help to test the robustness of threshold values used for
radiological protection of ecosystems.
Objectives
The proposed research project is integrated in the framework of the European project COMET
(COordination and iMplementation of a pan-European instrumenT for radioecology, 7th PCRD – Fission 2013). This project aims at characterizing epigenetic mechanisms induced in vertebrates exposed to
ionizing radiations, from DNA methylation (MS-AFLP) and DNA methylome (use of ME-DIP-chips)
measurement, to characterization of the impact on gene expression. These experiments will be
performed in the laboratory but samples from native species exposed in the Fukushima prefecture will
also be studied.
The applicant will be involved in these general analyses, from laboratory studies to possible field
applications. The work will be focused on applying and developing epigenetic biomarkers on biological
models chosen in the COMET project (fish, frogs and birds). Other complementary endpoints will also be
studied (e.g. genotoxicity, reprotoxicity), in order to be able to establish a possible correlation between
epigenetic modifications and physiological alterations.
Skills and conditions
As this post-doctoral position is proposed within the framework of the European research project
(COMET), interactions with other European, Ukrainian and Japanese partners of the project will be
favoured.
The post-doctoral applicant will have a solid formation in molecular biology to perform analyses of
epigenetic parameters . Minimum required experience will be a PhD. Salary will be commensurate with
applicant's experience but will be within 25-35 k€ per year.
He (she) will benefit from IRSN experimental platform (LRE, Cadarache, South of France – ca. 35km north
from Aix-en-Provence – http://www.irsn.fr). An 18 month post-doctoral contract will be concluded
between IRSN and the applicant.
For application, please send a curriculum vitae and a motivation letter before 15th of July 2014 to :
christelle.adam-guillermin@irsn.fr