Fig. 1

NAT structural features and action models. NATs may originate from shared bidirectional promoters, independent, or latent promoters found within genes. Based on the orientation with reference to sense genes, NATs can be classified as head-to-head (5′-regions overlap), tail-to-tail (3′-regions overlap), or embedded (one transcript is completely incorporated within the other). Based on the action model, NATs can also be divided into cis-NATs and trans-NATs