cell-biology
Telomere
Definition
Telomeres are repetitive nucleotide sequences (TTAGGG in vertebrates) capped by a protein complex called shelterin that protect the ends of chromosomes from degradation, end-to-end fusion, and recognition as DNA damage. Telomeres shorten with each cell division due to the end-replication problem, and critically short telomeres trigger cellular senescence or apoptosis. Telomere length is considered a biomarker of biological aging, and interventions that preserve or extend telomeres, including the peptide epithalon, are actively studied in gerontological research.