Readers of the m⁶A epitranscriptomic code

N⁶-methyl adenosine (m⁶A) is the most prevalent and evolutionarily conserved, modification of polymerase II transcribed RNAs. By post-transcriptionally controlling patterns of gene expression, m⁶A deposition is crucial for organism reproduction, development and likely stress responses. m⁶A mostly mediates its effect by recruiting reader proteins that either directly accommodate the modified residue in a hydrophobic pocket formed by their YTH domain, or otherwise have their affinity positively influenced by the presence of m⁶A. We firstly describe here the evolutionary history, and review known molecular and physiological roles of eukaryote YTH readers. In the second part, we present non YTH-proteins whose roles as m⁶A readers largely remain to be explored. The diversity and multiplicity of m⁶A readers together with the possibility to regulate their expression and function in response to various cues, offers a multitude of possible combinations to rapidly and finely tune gene expression patterns and hence cellular plasticity. This article is part of a Special Issue entitled: mRNA modifications in gene expression control edited by Dr. Soller Matthias and Dr. Fray Rupert.