RIVAgE : Epitranscriptomic regulation in adaptation to environmental stress in the oyster Crassostrea gigas

Epitranscriptomic modifications (RNA methylation, N6-mA or m6A) emerge as an additional level of regulation of gene expression, especially in response to stress in many animals. In oysters, the conditions of the maternal environment are reflected by specific signatures in oocyte epitranscriptomes which are transmitted to the next generation. We hypothesize that epitranscriptomic regulation would participate in the adaptation of the oyster Crassostrea gigas in one hand in short term by modulating the adaptive response of gene expression during environmental stresses and in the other hand in longer term by conditioning the development of the next generation.

The RIVAgE thesis project therefore aims to address the following questions:

• Objective 1: Does epitranscriptomic regulation participate in the regulation of gene expression during environmental stress in oysters? If so, is chromatin lockdown by non-coding RNA methylation (m6A-carRNA) involved?
• Objective 2: Do epitranscriptomic signatures induced by the maternal environment in oocytes affect the development of the next generation?

This knowledge will allow a better understanding of oyster adaptation at the individual and population levels, which are crucial issues at the fundamental level but also in the context of shellfish farming under increasing environmental pressure.