Abstract

During translation, ribosomes synthesize polypeptides using RNA molecules as templates. All cellular proteins are products of translation, and the identification of protein-coding regions is the primary goal of genome annotation. Beyond protein synthesis, translation has long been known to have regulatory functions independent of its products1,2. However, only with the advent of ribosome profiling was the broad scale and complexity of translated regions fully appreciated.

Recent interest in pervasive translation has exposed a lack of general terminology for translated regions that does not depend on the properties of their products or their sequence. In the absence of such terminology, a range of inconsistently defined terms are used to describe them. These terms are typically variations on ‘open reading frame’ (ORF) — for example, non-canonical ORF (ncORF), RiboSeq ORF, alternative ORF (altORF), translated ORF (tORF), small ORF (smORF), short ORF (sORF) and others. Such terms largely overlap and redundantly describe the same core concept: that the region in question is translated.

We intend the term translon to denote any region that is decoded by the ribosome.