Age-associated telomere shortening in Thoroughbred horses

Telomeres are genetically conserved repetitive terminal DNA that protect against genomic instability and shorten with ageing. Here, we reveal the leukocyte telomere length of Equus caballus by measuring terminal restriction fragments (TRFs) using Southern Blot analysis in a cohort of 43 Thoroughbred horses (age: 24 h–25 years). Heterogeneous TRFs were observed in each animal and large inter-animal variation in mean TRF was observed (range: 10.5–18.7 kbp). Mean TRFs were inversely correlated with age (r = −0.47). The estimated yearly rate of telomere attrition was 134 bp. Horses should be considered as an alternative animal model to investigate environmental and lifestyle factors that regulate telomeres and promote healthy ageing.