DROSOPHILA SCAFFOLD-ATTACHED REGIONS BIND NUCLEAR SCAFFOLDS AND CAN FUNCTION AS ARS ELEMENTS IN BOTH BUDDING AND FISSION YEASTS

Histone-depleted nuclei maintain sequence-specific interactions with genomic DNA at sites known as scaffold attachment regions (SARs) or matric attachment regions. We have previously shown that in Saccharomyces cerevisiae, autonomously replicating sequence elements bind the nuclear scaffold. Here, we extend these observations to the fission yeast Schizosaccharomyces pombe. In addition, we show that four SARs previously mapped in the genomic DNA of Drosophila melanogaster bind in vitro to nuclear scaffolds from both yeast species. In view of these results, we have assayed the ability of the Drosophila SARs have autonomously replicating sequence activity in budding yeast, and three function in fission yeast, while four flanking non-SAR sequences are totally inactive in both.