Monitoring the DNA Damage Response at Dysfunctional Telomeres.

Telomeres are repetitive DNA repeats that cap the ends of all eukaryotic chromosomes. Their proper maintenance is essential for genomic stability and cellular viability. Dysfunctional telomeres could arise through natural attrition of telomeric DNA or due to the removal of shelterin components. These uncapped chromosomal ends are recognized as DSBs by the DDR pathway, leading to the accumulation of DNA damage sensors at telomeres. The association of these DDR proteins with dysfunctional telomeres forms telomere dysfunction induced DNA damage foci (TIFs). Detection of TIFs at telomeres provides an opportunity to quantify the extent of telomere dysfunction and monitor downstream DNA damage signaling pathways. Here we describe a method for the detection of TIFs using a fluorescent in situ hybridization (FISH) approach.