Long terminal repeat retrotransposons of Mus musculus.
BACKGROUND
Long terminal repeat (LTR) retrotransposons make up a large fraction of the typical mammalian genome. They comprise about 8% of the human genome and approximately 10% of the mouse genome. On account of their abundance, LTR retrotransposons are believed to hold major significance for genome structure and function. Recent advances in genome sequencing of a variety of model organisms has provided an unprecedented opportunity to evaluate better the diversity of LTR retrotransposons resident in eukaryotic genomes.


RESULTS
Using a new data-mining program, LTR_STRUC, in conjunction with conventional techniques, we have mined the GenBank mouse (Mus musculus) database and the more complete Ensembl mouse dataset for LTR retrotransposons. We report here that the M. musculus genome contains at least 21 separate families of LTR retrotransposons; 13 of these families are described here for the first time.


CONCLUSIONS
All families of mouse LTR retrotransposons are members of the gypsy-like superfamily of retroviral-like elements. Several different families of unrelated non-autonomous elements were identified, suggesting that the evolution of non-autonomy may be a common event. High sequence similarity between several LTR retrotransposons identified in this study and those found in distantly-related species suggests that horizontal transfer has been a significant factor in the evolution of mouse LTR retrotransposons.
Genetics Department, University of Georgia, Athens, GA 30602, USA. mccarthy@uga.edu
Eugene M
EM
McCarthy
John F
JF
McDonald
D000818:Animals; D004247:DNA / Q000145:classification / Q000235:genetics; D030541:Databases, Genetic / Q000145:classification; D016678:Genome; D051379:Mice; D005810:Multigene Family / Q000235:genetics; D018626:Retroelements / Q000235:genetics*; D020079:Terminal Repeat Sequences / Q000235:genetics*; D009626:Terminology as Topic
D018626:Retroelements; D004247:DNA