Retrotransposon BARE-1 is a major, dispersed component of the barley (Hordeum vulgare L) genome

The barley BARE-1 is a transcribed, copia-like retroelement with well-conserved functional domains, an active promoter, and a copy number of at least 3 x 10(4). We examined its chromosomal localization by in situ hybridization. The long terminal repeat (LTR) probe displayed a uniform hybridization pattern over the whole of all chromosomes, excepting paracentromeric regions, telomeres, and nucleolar organizer (NOR) regions. The integrase probe showed a similar pattern. The 5'-untranslated leader (UTL) probe, expected to be the most rapidly evolving component, labeled chromosomes in a dispersed and non-uniform manner, concentrated in the distal regions, possibly indicating a targe site preference.