Three Saccharomyces cerevisiae strains lacking the telomerase RNA gene (tlc1) were generated by tetrad dissection from a heterozygous diploid (TLC1/tlc1). This results in strains whose telomeres are gradually shortened with each round of replication, thus mimicking telomere-attrition induced senescence. Next genomic DNA samples were collected before the telomeres became critically short, during telomere crises, and after so-called survivors have arisen through alternative telomere lengthening. The nine samples were treated with Micrococcal-nuclease to generate mononucleosomes, followed by paired-end sequencing, a procedure known as MnaseSeq. The purpose of the experiment is to explore how senescence affects nucleosome positioning/occupancy.