Short Interspersed Elements (SINEs)


Short interspersed elements (SINEs) are highly repetitive sequences that retrotranspose into eukaryotic DNA through intermediates transcribed by RNA polymerase III (pol III). In many species, SINEs are a ubiquitously dispersed feature of the whole genome, often constituting a significant (∼10%) mass fraction of total DNA. SINEs cause mutations both by their retrotransposition within genes and by unequal recombination, and are widely considered to be examples of ‘selfish’ or ‘parasitic’ DNA.

Keywords: SINEs; Alu; retrotransposition; transposons; selfish DNA

Figure 1.

Interspersed repeat structure. (a) The primate Alu left and right monomers are shown relative to their ancestor, 7SL. The two monomers are linked by a short AT‐rich region. Only the left monomer contains functional A and B boxes that are essential for RNA polymerase III transcription. The right monomer contains an additional 31 nucleotides of 7SL sequence not found in the left monomer (numbering is approximate). (b) Structure of the tRNA‐related rodent B2 SINE. The ancestor of the B2 tRNA‐related portion is lysine tRNA. Other species contain SINEs derived from glycine or arginine tRNAs that have similar structures (see Okada and Ohshima, ).



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Schmid, Carl W, and Rubin, Carol M(Sep 2005) Short Interspersed Elements (SINEs). In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0005325]