The analysis of Circe, an LTR retrotransposon of Drosophila melanogaster, suggests that an insertion of non-LTR retrotransposons into LTR elements can create chimeric retroelements.
Circe is a transposable element recently identified in Drosophila melanogaster which appears to be mostly associated with the constitutive heterochromatin. This element shows the structural features of a long terminal repeat (LTR)-containing retrotransposon: It is flanked by 240-bp-long terminal repeats, and its two open reading frames encode putative proteins resembling the gag and pol polyproteins of retroviruses. However, Circe displays striking similarities of both LOA and Ulysses, a non-LTR element and an LTR element, respectively. The result of its phylogenetic and structural analysis has allowed us to propose a new mechanism for non-LTR retrotransposon evolution.
Losada
A
A
Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.
Abad
J P
JP
Agudo
M
M
Villasante
A
A
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D010802:Phylogeny; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D018626:Retroelements / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D020079:Terminal Repeat Sequences / Q000235:genetics*
D004251:DNA Transposable Elements; D018626:Retroelements; D012194:RNA-Directed DNA Polymerase