Figure 1.

Schematic of Alu structure and transcript. (A) Representation of a typical transcript of a genomic Alu element with functional segments defined as the left and right monomers, A-tail, and 3′ unique region. (B) Schematic of the Alu base construct used in this study with 7SL promoter-enhancer sequence upstream of the Alu and the necessary restriction enzymes used for construct manipulation. The neomycin selection cassette in reverse orientation with a self-splicing intron that allows for the retrotransposition studies is introduced after the Alu and before the A-tail. The selection cassette contains a Pol III terminator (TTTT) at the 3′ end.