HAUSSMANN, M.F.; WINKLER, D.W.; O’REILLY, K.M.; HUNTINGTON, C.E.; VLECK, C.M.; Iowa St. Univ., Ames; Cornell Univ., Ithaca, NY; Univ. of Portland, OR; Harpswell, ME; Iowa St. Univ., Ames: Telomere shortening in birds varies with life span

The senescent decline in survival and reproductive performance with advancing age is a nearly universal pattern in the life history of animals. Birds live longer than mammals of similar body size but the mechanisms that dictate lifespan in birds are not well known. Cell survival in all vertebrates is dependent on the presence of telomeric DNA at the ends of linear chromosomes and cellular aging is normally accompanied by telomere shortening. We investigated telomere length in four bird species to determine whether telomeres shorten with age and at what rate. Blood samples were taken from known age zebra finches (Taeniopygia guttata), tree swallows (Tachycineta bicolor), Ad�lie penguins (Pygoscelis adeliae) and Leach’s storm-petrels (Oceanodroma leucorhoa) for telomere length analysis. Mean telomere lengths decrease as age increases in zebra finches, tree swallows, and Ad�lie penguins. Surprisingly, telomeres do not shorten with age in Leach’s storm-petrels but in contrast lengthen. Additionally, there was a strong, positive correlation between the maximum observed life span and the rate of change in telomere length for each species. These results are particularly interesting because telomeres shorten with age in essentially all other organisms that have been examined. Leach’s storm-petrels are long-lived for their body size, whereas the other birds are relatively short-lived. If storm-petrels have evolved other age-combating adaptations such as active telomere elongation by up-regulation of telomerase, freeing them from the constraint on cellular replicative life span normally imposed by shortening telomeres, then they may provide insight into other fundamental questions in aging biology.