XVI International Botanical Congess

The highly organized and defined arrangement of DNA in the cell nucleus is an important attribution to a timely and spatially correct gene expression. Detailed cytological investigations with improved molecular and cytological techniques elucidated the higher order structure of the chromosomes. Here we concentrate on the role of repetitive DNA in maintaining this order. Repetitive DNA elements mainly responsible for the phenomenon of the C-value paradox are represented by centromeric, subtelomeric and intercalated heterochromatic blocks of satellite DNA, telomeric repeats and dispersely distributed retrotransposon-like elements. New insights in structure and function of these elements are gained which are fruitful and stimulating for plant cell research especially in evolutionary studies and plant breeding.