A contiguous 60 kb genomic stretch from barley reveals molecular evidence for gene islands in a monocot genome

The contiguous DNA sequence of a 60 kb genomic interval of barley chromosome 4HL has been assembled, The region harbours a single and novel gypsy-like retrotransposon, designated BAGY-1. Only three genes appear to reside in the genomic stretch, One predicts a plant homologue of ribophorin I, a subunit of the oligosaccharyltransferase-protein complex located in the rough endoplasmatic reticulum, The second is similar to the Drosophila g1 gene encoding a ring finger protein involved in developmental processes, The observed gene density is similar to 5-fold lower than in the best characterized dicot genome of Arabidopsis but 6- to 10-fold higher than expected from an equidistant gene distribution in the complex barley genome, Our data suggest that the 60 kb genomic interval represents part of a gene island, a seemingly distinctive feature of grass genomes.