Epitranscriptomics and epigenetics: two sides of the same coin?

Gene expression is an intricate biological process that bridges gap between the genotype and the phenotype. Canonical and hereditable epigenetic mechanisms, such as histone and DNA modifications, regulate the release of genetic information encoded in DNA without altering the underlying sequence. Many other non-canonical players, such as chromatin regulators and noncoding RNAs, are also involved in regulating gene expression. Recently, RNA modifications (epitranscriptomics) have been shown to hold enormous potential in shaping cellular transcriptomes. However, their co-transcriptional nature and uncertain heritability mean that they fall outside the current definition of epigenetics, sparking an ongoing debate in the field. Here we will discuss the relationship between canonical and non-canonical epigenetic mechanisms that govern gene expression and offer our perspective on whether (or not) epitranscriptomic modifications can be classified as epigenetic mechanisms.