title: Telomerase expression is differentially regulated in birds of differing life span.
abstract: Cellular senescence caused by telomere shortening has been suggested as one potential causal agent of aging. In some tissues, telomeres are maintained by telomerase; however, telomerase promotes tumor formation, suggesting a trade-off between aging and cancer. We predicted that telomerase activity should vary directly with life span. We determined telomerase activity in bone marrow in cross-sectional samples from two short-lived bird species and two long-lived bird species. The two short-lived species had high telomerase activity as hatchlings but showed a sharp downregulation in both the young and old adults, whereas the two long-lived species had relatively high telomerase activity in bone marrow that did not decrease with age. In zebra finches, the age-related change in telomerase activity varied in different tissues. Telomerase activity increased late in life in skeletal muscle, liver, and gonad, but not in blood or bone marrow.
authors.affiliation: Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA. hauss@iastate.edu
authors.forename: Mark F
authors.initials: MF
authors.lastname: Haussmann
authors.forename: David W
authors.initials: DW
authors.lastname: Winkler
authors.forename: Charles E
authors.initials: CE
authors.lastname: Huntington
authors.forename: Ian C T
authors.initials: IC
authors.lastname: Nisbet
authors.forename: Carol M
authors.initials: CM
authors.lastname: Vleck
mesh_terms: D000375:Aging; D000818:Animals; D001717:Birds; D001854:Bone Marrow Cells / Q000378:metabolism; D008136:Longevity; D020308:Songbirds; D013045:Species Specificity; D019098:Telomerase / Q000096:biosynthesis*; D016615:Telomere / Q000648:ultrastructure*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D019098:Telomerase