Retrotransposon BARE-1 and Its Role in Genome Evolution in the Genus Hordeum.
AUTOR(ES)
Vicient, CM
RESUMO
The replicative retrotransposon life cycle offers the potential for explosive increases in copy number and consequent inflation of genome size. The BARE-1 retrotransposon family of barley is conserved, disperse, and transcriptionally active. To assess the role of BARE-1 in genome evolution, we determined the copy number of its integrase, its reverse transcriptase, and its long terminal repeat (LTR) domains throughout the genus Hordeum. On average, BARE-1 contributes 13.7 x 10(3) full-length copies, amounting to 2.9% of the genome. The number increases with genome size. Two LTRs are associated with each internal domain in intact retrotransposons, but surprisingly, BARE-1 LTRs were considerably more prevalent than would be expected from the numbers of intact elements. The excess in LTRs increases as both genome size and BARE-1 genomic fraction decrease. Intrachromosomal homologous recombination between LTRs could explain the excess, removing BARE-1 elements and leaving behind solo LTRs, thereby reducing the complement of functional retrotransposons in the genome and providing at least a partial "return ticket from genomic obesity."
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=144304Documentos Relacionados
- Genome evolution of wild barley (Hordeum spontaneum) by BARE-1 retrotransposon dynamics in response to sharp microclimatic divergence
- Chloroplast Genome Evolution in the Genus Avena
- Retrotransposon-mediated genome evolution on a local ecological scale
- Molecular evolution of the Adh1 locus in the genus Zea.
- Contribution of ultra-short invasive elements to the evolution of the mitochondrial genome in the genus Podospora.