Figure 1.

Schematic representation of retrotransposons classes organization. Retrotransposons are divided in three major classes: long interspersed elements (LINE), short interspersed elements (SINE) and long terminal repeat (LTR). Left, full length retrotransposons: the regulatory sequences are represented in grey; RNA Pol II and Pol III promoters are indicated with arrows; the protein coding sequences are indicated with colors. Middle, most common transposable elements (TEs) in the human genome. Right, retrotransposon coverage of the human genome (see the main text for details).