Human genes contain many transposable elements

Numerous repetitive elements are found in the human gene (HGO) encoding homogentisate 1,2-dioxygenase, the enzyme whose deficiency causes alkaptonuria. The upper row diagrams the positions of the HGO exons. The locations of Alus (blue), other SINEs (purple), and LINEs (yellow) in the HGO sequence are indicated in the lower row.

[Data from B. Granadino, D. Beltrán-Valero de Bernabé, J. M. Fernández-Cañón, M. A. Peñalva, and S. Rodríguez de Córdoba, “The Human Homogentisate 1,2-dioxygenase (HGO) Gene,” Genomics 43, 1997, 115]