Structure and evolution of Cyclops: a novel giant retrotransposon of the Ty3/Gypsy family highly amplified in pea and other legume species.

摘要: We characterized a novel giant Gypsy-like retrotransposon, Cyclops, present in about 5000 copies the genome of Pisum sativum. The individual element Cyclops-2 measures 12 314 bp including long terminal repeats (LTRs) 1504 and 1594 bp, respectively, showing 4.1% sequence divergence between one another. carries polypurine tract (PPT) an unusual primer binding site (PBS) complementary to tRNA-Glu. is bounded by 5 target duplications harbors three successive internal regions with homology retroviral genes gag (424 codons) pol (1382 additional open reading frame (423 unknown function indicating element's potential capacity for gene transduction. region contains motifs related enzymes protease, reverse transcriptase, RNAse H integrase same typical order (5′-PR-RT-RH-IN-3′) known retroviruses retrotransposons. disrupted several mutations suggesting that does not encode functional enzymes. A phylogenetic analysis transcriptase domain confirms our differential genetic assessment Cyclops from pea no specific relationship previously described elements plants. Genomic Southern hybridizations show abundant only but also common bean, mung broad soybean nut may be useful tool analyzing genomes agronomically important legumes.