The rate of telomere loss is related to maximum lifespan in birds

Abstract

Telomeres are highly conserved regions of DNA that protect the ends of linear chromosomes. The loss of telomeres can signal an irreversible change to a cell's state, including cellular senescence. Senescent cells no longer divide and can damage nearby healthy cells, thus potentially placing them at the crossroads of cancer and ageing. While the epidemiology, cellular and molecular biology of telomeres are well studied, a newer field exploring telomere biology in the context of ecology and evolution is just emerging. With work to date focusing on how telomere shortening relates to individual mortality, less is known about how telomeres relate to ageing rates across species. Here, we investigated telomere length in cross-sectional samples from 19 bird species to determine how rates of telomere loss relate to interspecific variation in maximum lifespan. We found that bird species with longer lifespans lose fewer telomeric repeats each year compared with species with shorter lifespans. In addition, phylogenetic analysis revealed that the rate of telomere loss is evolutionarily conserved within bird families. This suggests that the physiological causes of telomere shortening, or the ability to maintain telomeres, are features that may be responsible for, or co-evolved with, different lifespans observed across species.This article is part of the theme issue ‘Understanding diversity in telomere dynamics'.

Dynamics of telomere length in captive Siamese cobra (Naja kaouthia) related to age and sex

“…Similar age-related telomere length sex differences were also found in water pythons and other vertebrates (Barrett & Richardson, 2011;Jemielity et al, 2007;Ujvari & Madsen, 2009), indicating a relationship between high mortality and telomere maintenance in somatic cells resulting in shorter life span (Hornsby, 2007;Kirkwood, 1977;Tricola et al, 2018). Similar age-related telomere length sex differences were also found in water pythons and other vertebrates (Barrett & Richardson, 2011;Jemielity et al, 2007;Ujvari & Madsen, 2009), indicating a relationship between high mortality and telomere maintenance in somatic cells resulting in shorter life span (Hornsby, 2007;Kirkwood, 1977;Tricola et al, 2018).…”

Understanding diversity in telomere dynamics

“…Two papers in this issue harness these emerging data on avian telomeres to provide important new insights into the relationship between telomere length and longevity. Tricola et al [19] compare average telomere length and rates of change in telomere length with age across 19 species of birds. They show that species with longer maximum lifespans have slower rates of telomere loss with age than species with shorter lifespans.…”

“…But longitudinal studies are difficult, especially in long-lived species. The comparative analysis of Tricola et al [19] and the meta-analysis of Wilbourn et al [20] are both limited to using cross-sectional data. For this reason, their conclusions regarding the importance of initial telomere length, and the rate of telomere loss over different time scales, for lifespan remain tentative.…”

Divergent patterns of telomere shortening in tropical compared to temperate stonechats

“…that, in general, older individuals have shorter telomeres than younger ones with the greatest loss in telomeres occurring early in life (Heidinger et al, 2012;Pauliny, Larsson, & Blomqvist, 2012;Salomons et al, 2009;Spurgin et al, 2018;Tricola et al, 2018).…”

“…In mammals, a comparative study found that short-lived, small species have longer telomeres and higher telomerase expression than long-lived, large species (Gomes et al, 2011). In birds, absolute telomere length does not seem to relate to variation in lifespan between species; however, longer-lived avian species seem to have lower rates of telomere shortening than shorter-lived species (Dantzer & Fletcher, 2015;Haussmann et al, 2003;Sudyka, Arct, Drobniak, Gustafsson, & Cichoan, 2016;Tricola et al, 2018). In birds, absolute telomere length does not seem to relate to variation in lifespan between species; however, longer-lived avian species seem to have lower rates of telomere shortening than shorter-lived species (Dantzer & Fletcher, 2015;Haussmann et al, 2003;Sudyka, Arct, Drobniak, Gustafsson, & Cichoan, 2016;Tricola et al, 2018).…”