Telomere biology and telomerase regulation across species: evolutionary insights into aging, longevity, and genome stability.

Telomeres are protective DNA-protein structures at chromosome ends that play a crucial role in maintaining genome stability and regulating cellular aging. Their progressive shortening during cell division is counteracted by telomerase, a ribonucleoprotein enzyme composed of a catalytic subunit namely, telomerase reverse transcriptase catalytic subunit (TERT) and an RNA template i.e., telomerase RNA component (TERC), which restores telomeric repeats. Telomerase activity varies across species and is closely associated with differences in longevity. This review synthesizes current knowledge on telomere biology across diverse taxa, focusing on evolutionary selection patterns, age-related gene expression, and key regulatory mechanisms. By integrating insights from comparative genomics, functional studies, and computational approaches, it highlights both conserved and species-specific factors influencing lifespan and age-related processes. The review also discusses emerging computational frameworks for predicting telomere dynamics and outlines their potential applications in telomere-based therapies, livestock improvement, and conservation biology.