FIGURE 1.

Schematic representation of sense and antisense transcripts from bi-directionally transcribed loci. Commonly used descriptions are head-to-head, tail-to-tail, embedded and intronic (from top). The percent representation in the human genome is from Balbin et al. (2015). Importantly, transcripts in tail-to-tail and full overlap configuration potentially form double-stranded RNA whereas the other two categories do not. Other terms used are ‘convergent’ (tail-to-tail), divergent (head-to-head), or ‘non-overlapping’ (embedded).