Effects of environmental stress on developmental plasticity of behavioral traits in the mangrove rivulus. Anchoring the phenotype with the methylome, proteome and transcriptome in brain and gonads

The present project aims to investigate the developmental plasticity of
behavioral traits in an isogenic lineage of the mangrove rivulus, Kryptolebias
marmoratus, and the role of DNA methylation in the regulation of this
plasticity. Rivulus is one of the two self-fertilizing hermaphrodite vertebrate
species presenting the unique advantage to show high level of behavioral
plasticity with very low level of genetic diversity. This particularity allows the
precise identification of genetic and environmental sources of plasticity. We
will investigate how environmental factors (salinity and exposure to 17-α-
ethinylestradiol) during early life stages (ELS) can affect aggressiveness
and boldness in adults. After personality traits assessment using videotracking,
the role of molecular mechanisms underlying developmental
behavioral plasticity in brain will be investigated. The cellular phenotype will
be analysed at the protein expression level using a quantitative label- and
gel-free proteomic approach in collaboration with Prof. D. Kuëltz (UC
Davis), and at the transcriptomic level using RNA-seq. Simultaneously, we
will analyse genome-wide level of DNA methylation in adult’s brain using an
original workflow of Reduced Representation Bisulfite Sequencing (RRBS).
This methodology will be developed in collaboration with Dr. A. Chatterjee
and Dr. P. Stockwell (University of Otago). Specific bioinformatics tools will
be developed for this purpose. The proteome, transcriptome and methylome
will then be characterized in ovotestis of hermaphrodite adult fish by clearly
distinguishing male and female tissues using laser microdissection.
Therefore, a clear comparison between somatic and germ cells will be
established for the first time in response to environmental stimuli during
ELS. This exploratory research project will open the door to future
researches on the mechanisms of transgenerational epigenetic inheritance
in vertebrates. It will be the first to anchor behavioral traits with three levels
of OMICS analysis with the aim to mechanistically explain phenotypic
variability in this promising model species.