Anthology of Human Repetitive DNA
253
LTR Retrotransposons
A class of retrotransposons that are reverse transcribed in the cytoplasm. The resulting
cDNA is integrated into the host genome, forming a provirus flanked by long
terminal repeats.
Microsatellites
DNA sequences, typically shorter than 1000 bp, composed of tandemly repeated units
1 to 10 bp long (1–6 bp or 1–13 bp ranges are also used). Microsatellites are also
known as short tandem repeats (STR) or simple sequence repeats (SSRs).
Minisatellites
DNA sequences composed of tandemly repeated units longer than in microsatellites.
Minisatellites span from 1 kb to 100 kb and are also known as variable number of
tandem repeats (VNTRs).
Non-LTR Retrotransposons
A class of retrotransposons that are transposed via target-primed reverse transcription.
Autonomous non-LTR retrotransposons encode reverse transcriptase.
Processed Pseudogene (Retropseudogene)
A pseudogene derived from usually spliced and polyandenylated host mRNA by
LINE-mediated reverse transcription.
Provirus
A DNA copy of a retrovirus inserted into the genome.
Pseudogene
A nonfunctional gene copy.
Recombination
The exchange of DNA or RNA molecules.
Repetitive Elements (Repeats)
DNA fragments present in multiple copies in the genome without clearly assigned
biological function.
Ribonuclease H (RNase H)
An enzyme that degrades the RNA strand of RNA–DNA hybrid molecules.
Retrotransposition (Retroposition)
A process involving transcription, processing of mRNA, translation, reverse
transcription of the transcribed mRNA, and integration of the resulting cDNA into the
host genome.
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