Aging has been linked to telomeres, which are DNA segments at the ends of eukaryotic chromosomes. Telomere shortening to a critical length can trigger aging and shorten life spans through DNA damage at chromosome ends and loss of cellular viability. However, whether telomere length is a universal determinant of species longevity is unclear.

Researchers used a high-throughput quantitative fluorescence in situ hybridization technique to measure telomere length in peripheral blood mononuclear cells from a variety of bird and mammal species with different life spans and body sizes.

In a cross-sectional analysis, the authors sampled blood at one time point for individuals that varied widely in age. The animals included laboratory mice, bottlenose dolphins, goats, reindeer, American flamingos, griffon vultures, Audouin's gulls, and Sumatran elephants.

Telomere shortening rate, but not initial telomere length alone, appeared to be a predictor of species life span. Body weight and heart rate were less powerful than telomere shortening rate at predicting species life span.

According to the authors, the findings suggest that telomere shortening, and the resulting DNA damage and cellular senescence, may be a determinant of species life span.

https://www.pnas.org/content/early/2019/07/02/1902452116

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