Understanding aging is a grand challenge in biology. Exceptionally
long-lived animals have mechanisms that underpin extreme longevity.
Telomeres are protective nucleotide repeats on chromosome tips that
shorten with cell division, potentially limiting life span. Bats are the
longest-lived mammals for their size, but it is unknown whether their
telomeres shorten. Using >60 years of cumulative mark-recapture field
data, we show that telomeres shorten with age in Rhinolophus ferrumequinum and Miniopterus schreibersii, but not in the bat genus with greatest longevity, Myotis. As in humans, telomerase is not expressed in Myotis myotis blood or fibroblasts. Selection tests on telomere maintenance genes show that ATM and SETX, which repair and prevent DNA damage, potentially mediate telomere dynamics in Myotis bats. Twenty-one telomere maintenance genes are differentially expressed in Myotis,
of which 14 are enriched for DNA repair, and 5 for alternative
telomere-lengthening mechanisms. We demonstrate how telomeres,
telomerase, and DNA repair genes have contributed to the evolution of
exceptional longevity in Myotis bats, advancing our understanding of healthy aging.