[Genome organization and primary structure of the BamHI fragment of highly repetitive DNA from Hordeum vulgare].

The primary structure of three highly repetitive DNA sequences, which are: the most widespread repeats in a number of Hordeum species, represented by 10(5) copies in the genome of Hordeum vulgare, and belong to the BamHI fragment, was studied. The organization of this fragment in the barley genome was described. The computer analysis of the primary structure indicated a great number of inverted repeats (two of them are flanked by short direct repeats) in the BamHI fragment and revealed the short subrepeats of the A, B, C types, five potential RNA-polymerase II sites, one site for RNA polymerase III, open reading frame of 294 b.p. or 210 b.p., sites for polyadenylation and enhancer sequence. The presence of a mobile element (95-568 bp) is very likely in the BamHI fragment, taking into account the location of the mentioned structures along the fragment. This mobile element contains the subrepeats of only A and B types, all sites of transcription initiation, the open reading frame and the inverted repeats on both ends, flanked by the short direct repeats. The transposition mechanisms probably play an essential part in the origin and propagation of the studied BamHI fragment. The presence of potential functional sites in the fragment indicates the possibility of transcription and translation of some highly repetitive Hordeum vulgare DNA.