Telomere

Definition

Telomeres are repetitive nucleotide sequences (TTAGGG in humans) and associated shelterin protein complexes located at the ends of linear chromosomes. They serve as protective caps that prevent chromosomal end fusion, degradation, and recognition as double-strand DNA breaks. With each somatic cell division, telomere sequences shorten due to the end-replication problem, and cells eventually reach a critically short telomere length that triggers replicative senescence or apoptosis. In germline and stem cells, the enzyme telomerase (encoded by hTERT) maintains telomere length by synthesizing new TTAGGG repeats. Telomere attrition is recognized as one of the hallmarks of cellular aging.

Research Context

Telomere biology is directly relevant to longevity and cellular aging research involving peptides such as Epithalon. Epithalon has been studied for its ability to activate telomerase (hTERT) in somatic cell types that normally exhibit low telomerase expression, with documented telomere elongation in human fetal fibroblasts and extended replicative lifespan in cell culture models. Measurement of telomere length in preclinical research uses methods including TRF (terminal restriction fragment) Southern blotting, quantitative PCR-based relative telomere length assay (qPCR-TLA), and FISH (fluorescence in situ hybridization) with telomere-specific probes.