Use of Artemia as model organism to study epigenetic control of phenotypes relevant for aquaculture species

Epigenetics is the study of reversible changes in gene function that occur without modifications in the DNA sequence. Epigenetic variation that are environmentally determined, contributes to inter-individual variation in gene expression and thus to variation in development of phenotypes in an individual or even throughout the entire population. These epigenetic modifications can in some cases be inherited by subsequent generations, even when the initial external stimuli is no longer present in the environment of these organisms. Epigenetic modification occurs through different molecular mechanisms including non-coding small RNA molecules, DNA methylation or histone tail modifications. Among the environmental stressors animals (aquatic or terrestrial) can encounter, pathogen attack and heat stress are quite common. The work presented in this thesis indicated that, the organisms respond to biotic or abiotic environmental stressors with battery of adaptive phenotypes (i.e. increased resistance, different gene expression patterns and protein production). Interestingly, overall results leave no doubt on the role of epigenetic modifications, such as DNA methylation, histone H3 and H4 acetylation and H3K4Me3 on emergence of these new phenotypes