As interest grows in treating human aging and extending life, there is also a corresponding interest in investigating long-lived species so as to establish the factors that determine differing length of life. As a companion piece to last month's post on investigations into the biology of long-lived ocean quahog clams, the species Arctica islandica, here is another paper on the subject. This one focuses on teleomere biology, with results that are largely to be expected given other studies demonstrating a very consistent stability of metabolism across the potentially centuries-long life span of this species:
The shortening of telomeres as a causative factor in ageing is a widely discussed hypothesis in ageing research. The study of telomere length and its regenerating enzyme telomerase in the longest-lived non-colonial animal on earth, Arctica islandica, should inform whether the maintenance of telomere length plays a role in reaching the extreme maximum lifespan (MLSP) of more than 500 years in this species.
Since longitudinal measurements on living animals cannot be achieved, a cross-sectional analysis of a short-lived (MLSP 40 years from the Baltic Sea) and a long-lived population (MLSP 226 years Northeast of Iceland) and in different tissues of young and old animals from the Irish Sea was performed. A high heterogeneity of telomere length was observed in investigated A. islandica over a wide age range (10-36 years for the Baltic Sea, 11-194 years for Irish Sea, 6-226 years for Iceland). Constant telomerase activity and telomere lengths were detected at any age and in different tissues; neither correlated with age or population habitat.
Stable telomere maintenance might contribute to the long lifespan of A. islandica. Telomere dynamics are no explanation for the distinct MLSPs of the examined populations and thus the cause of it remains to be investigated.