Tissue-specific temperature dependence of RNA editing levels in zebrafish

RNA editing by adenosine deaminase acting on RNA (ADAR) occurs in all metazoans and fulfils several functions. Here, we examined effects of acclimation temperature (27 °C, 18 °C,13 °C) on editing patterns in six tissues of zebrafish (Danio rerio). Sites and total amounts of editing differed among tissues. Brain showed the highest levels, followed by gill and skin. In these highly edited tissues, decreases in temperatures led to large increases in total amounts of editing and changes in specific edited sites. Gene ontology analysis showed both similarities (e.g., endoplasmic reticulum stress response) and differences in editing among tissues. The majority of edited sites were in transcripts of transposable elements and the 3'UTR regions of protein coding genes. By experimental validation, translation efficiency was directly related to extent of editing of the 3'UTR region of an mRNA. RNA editing increases 3'UTR polymorphism and affects efficiency of translation. Such editing may lead to temperature-adaptive changes in the proteome through altering relative amounts of synthesis of different proteins.