TY  - JOUR
A1  - Schmitz, Jürgen
A1  - Churakov, Gennady
A1  - Zischler, Hans
A1  - Brosius, Jürgen
T1  - A Novel Class of Mammalian-Specific Tailless Retropseudogenes
Y1  - 2004/10/01 
JF  - Genome Research 
JO  - Genome Research 
SP  - 1911 
EP  - 1915 
DO  - 10.1101/gr.2720104 
VL  - 14 
IS  - 10a 
UR  - http://genome.cshlp.org/content/14/10a/1911.abstract 
N2  - In addition to their central function in protein biosynthesis, tRNAs also play a pervasive role in genome evolution and architecture because of their extensive ability to serve as templates for retroposition. Close to half of the human genome consists of discernible transposable elements, a vast majority of which are derived from RNA via reverse transcription and genomic integration. Apart from the presence of direct repeats (DRs) that flank the integrated sequence of retroposons, genomic integrations are usually marked by an oligo(A) tail. Here, we describe a novel class of retroposons that lack A-tails and are therefore termed tailless retropseudogenes. Analysis of ∼2500 tRNA-related young tailless retropseudogene sequences revealed that they comprise processed and unprocessed (pre-)tRNAs, 3′-truncated in their loop regions, or truncated tRNA-derived SINE RNAs. Surprisingly, their mostly nonrandom integration is dependent on the priming of reverse transcription at sites determined by their 3′-terminal 2-18 nucleotides and completely independent from oligoadenylation of the template RNA. Thus, tailless retropseudogenes point to a novel, variant mechanism for the biogenesis of retrosequences. 
ER  -