Molecular Organization of 5S Ribosomal DNА of Deschapmpsia antarctica

Deschampsіa antarctіca, one of the two angiosperm species growing in the extreme conditions of Antarctica, is a unique model for studying the relationship between genetic polymorphism and such factors of evolution as isolation, migration and adaptation to new environmental conditions. Molecular markers represent a useful tool for the investigation of these questions. To examine the potential of 5S rDNA to be used for the discrimination of D. antarctica populations we cloned and sequenced this genomic region for plants from three populations of this species from Maritime Antarctica. It was shown that in the genome of D. antarctica at least two structural classes of 5S rDNA are present, which differ by numerous base substitutions and insertions/deletions in the intergenic spacer. Based on this structural polymorphism we propose to apply this region for the evaluation of the intraspecific genetic diversity of D. antarctica.