What is telomere length, and how does it relate to cellular processes?

Telomere length is the protective cap at the end of chromosomes that shortens with each cell division.

Telomeres are repetitive DNA sequences that protect the ends of chromosomes from degradation and fusion with other chromosomes. As cells divide, telomeres shorten until they reach a critical length, triggering cellular senescence or apoptosis. Telomere length is therefore a crucial factor in regulating cellular lifespan and preventing genomic instability.

Telomere length is maintained by the enzyme telomerase, which adds telomeric repeats to the ends of chromosomes. Telomerase activity is high in stem cells and germ cells, which have the ability to divide indefinitely, but is low in most somatic cells, leading to telomere shortening and eventual cell death.

Short telomeres have been associated with ageing, age-related diseases, and cancer. Telomere dysfunction can lead to chromosomal abnormalities, DNA damage response, and cellular senescence, which contribute to the development of cancer and other diseases.

Understanding telomere length and its regulation is therefore important for understanding cellular processes such as ageing, disease, and cancer. Research into telomere biology has led to the development of telomerase-targeted therapies for cancer and potential interventions for age-related diseases.