Conservative Protein RCC1 is a New Component of Black Bands of Drosophila Melanogaster Polytene Chromosomes

Previously, the RCC1 gene (Regulator of Chromosome Condensation 1), which is considered a regulator of chromosome condensation in the cell cycle, was characterized. This gene encodes a nuclear protein whose amino acid sequence is highly conserved among all eukaryotes and consists of seven repeating units. The authors have shown that all the most prominent black bands of polytene chromosomes (260 bands) and the chromocenter bind antibodies to this protein. Antibodies to the xenopus RCC1 protein specifically bind to the Drosophila and human RCC1 protein, while the relative amount of the RCC1 protein increases in Drosophila lines with under-replication suppression compared to the wild type.