Program > Browse abstracts by author > Vallier Agnès

Phenotypic plasticity is the ability for one genotype to yield different phenotypes in response to environmental changes. This process may provide organisms with the capacity to adjust their phenotype to better fit their environment as it changes. Most of the mechanisms that are at play in generating phenotypic plasticity are epigenetic mechanisms, such as histone marks, DNA methylation or small RNAs, allowing differential expression of genes, and eventually result in phenotypic changes. Epigenetic mechanisms have often been documented to fluctuate with the environment. Not only these mechanisms regulate gene expression, but they are also involved in the repression of transposable elements (TEs). TEs are repeated DNA sequences potentially capable of moving within genomes. Thanks to their transposition mechanisms, but also to their inherent regulatory sequences, TEs are known to impact gene expression, genome architecture and integrity. We hypothesize that TEs' control mechanisms and regulatory components, might also vary with the environment and potentially lead to changes in TE expression and transposition rate, and in turn alter gene expression. To test this hypothesis, we investigated the influence of TE content on phenotypes in Drosophila melanogaster, and as a potential driver of phenotypic plasticity. We took advantage of genetically engineered fruit flies that bear different TE content but identical genetic background, to tackle this question in a controlled manner. First, phenotypic tests were conducted and revealed significant differences between the lines harbouring different TE content. We further investigated the plastic response of these phenotypes in a variety of environments and stressors. Results depict genotype by environment interactions for multiple traits measured in variable environments, suggesting that indeed TEs contribute to plasticity.