Telomere shortening and survival in free-living corvids

Abstract

Evidence accumulates that telomere shortening reflects lifestyle and predicts remaining lifespan, but little is known of telomere dynamics and their relation to survival under natural conditions. We present longitudinal telomere data in free-living jackdaws (Corvus monedula) and test hypotheses on telomere shortening and survival. Telomeres in erythrocytes were measured using pulsed-field gel electrophoresis. Telomere shortening rates within individuals were twice as high as the population level slope, demonstrating that individuals with short telomeres are less likely to survive. Further analysis showed that shortening rate in particular predicted survival, because telomere shortening was much accelerated during a bird's last year in the colony. Telomere shortening was also faster early in life, even after growth was completed. It was previously shown that the lengths of the shortest telomeres best predict cellular senescence, suggesting that shorter telomeres should be better protected. We test the latter hypothesis and show that, within individuals, long telomeres shorten faster than short telomeres in adults and nestlings, a result not previously shown in vivo. Moreover, survival selection in adults was most conspicuous on relatively long telomeres. In conclusion, our longitudinal data indicate that the shortening rate of long telomeres may be a measure of 'life stress' and hence holds promise as a biomarker of remaining lifespan.

Mother–offspring and nest-mate resemblance but no heritability in early-life telomere length in white-throated dippers

“…Indeed, early development is a period characterized by rapid telomere shortening [59], and faster telomere shortening early in life has been demonstrated in the wild, e.g. in jackdaws (Corvus monedula) [8]. Similarly, Andrew et al [61] showed that 49% of the variation in telomere length could be attributed to (environmental) family effects in a human twin study.…”

“…Telomere length has been shown to significantly predict life-history parameters in a number of organisms, both when telomeres are measured early in life [4] and during adulthood [5]. For example, telomere length (or their rate of shortening) has been linked to lifespan in humans [6] and several bird species, both in captivity [4] and in natural populations [5,7,8]. More recently, it has been found that telomere length may not only be positively related to individual fitness through its link with lifespan, but also as a mediator of reproductive trade-offs [9].…”

Telomere length reflects phenotypic quality and costs of reproduction in a long-lived seabird

“…Class II telomere length [50] was analysed as described in Salomons et al [17], with some modifications. Briefly, we removed the glycerol buffer, washed the blood cells with 2 per cent EDTA and isolated DNA from erythrocytes (7 ml cells) using a CHEF Genomic DNA Plug kit (Bio-Rad, Hercules, CA, USA).…”

Seasonal variation in telomere length of a hibernating rodent

“…Telomere length dynamics have been correlated with rates of ageing and can predict future survival [11,12]. However, whether telomeres directly contribute to, or merely are affected by, the processes causing ageing is not known [13].…”