scholarly journals Individual variation in early‐life telomere length and survival in a wild mammal

2019 ◽  
Vol 28 (18) ◽  
pp. 4152-4165 ◽  
Author(s):  
Sil H. J. Lieshout ◽  
Amanda Bretman ◽  
Chris Newman ◽  
Christina D. Buesching ◽  
David W. Macdonald ◽  
...  
2020 ◽  
Author(s):  
Sil H. J. van Lieshout ◽  
Alex Sparks ◽  
Amanda Bretman ◽  
Chris Newman ◽  
Christina D. Buesching ◽  
...  

Understanding individual variation in fitness-related traits requires separating the environmental and genetic determinants. Telomeres are protective caps at the ends of chromosomes that are thought to be a biomarker of senescence as their length predicts mortality risk and reflect the physiological consequences of environmental conditions. The relative contribution of genetic and environmental factors to individual variation in telomere length is however unclear, yet important for understanding its evolutionary dynamics. In particular, the evidence for transgenerational effects, in terms of parental age at conception, on telomere length is mixed. Here, we investigate the heritability of telomere length, using the ‘animal model’, and parental age at conception effects on offspring telomere length in a wild population of European badgers (Meles meles). While we found no heritability of telomere length, our power to detect heritability was low and a repeatability of 2% across individual lifetimes provides a low upper limit to ordinary heritability. However, year (25%) and cohort (3%) explained greater proportions of the phenotypic variance in telomere length. There was no support for parental age at conception effects, or for longitudinal within-parental age effects on offspring telomere length. Our results indicate a lack of transgenerational effects through parental age at conception and a low potential for evolutionary change in telomere length in this population. Instead, we provide evidence that individual variation in telomere length is largely driven by environmental variation in this wild mammal.


2016 ◽  
Vol 283 (1825) ◽  
pp. 20152949 ◽  
Author(s):  
Christopher Beirne ◽  
Laura Waring ◽  
Robbie A. McDonald ◽  
Richard Delahay ◽  
Andrew Young

Senescence has been hypothesized to arise in part from age-related declines in immune performance, but the patterns and drivers of within-individual age-related changes in immunity remain virtually unexplored in natural populations. Here, using a long-term epidemiological study of wild European badgers ( Meles meles ), we (i) present evidence of a within-individual age-related decline in the response of a key immune-signalling cytokine, interferon-gamma (IFN γ ), to ex vivo lymphocyte stimulation, and (ii) investigate three putative drivers of individual variation in the rate of this decline (sex, disease and immune cell telomere length; ICTL). That the within-individual rate of age-related decline markedly exceeded that at the population level suggests that individuals with weaker IFN γ responses are selectively lost from this population. IFN γ responses appeared to decrease with the progression of bovine tuberculosis infection (independent of age) and were weaker among males than females. However, neither sex nor disease influenced the rate of age-related decline in IFN γ response. Similarly, while ICTL also declines with age, variation in ICTL predicted neither among- nor within-individual variation in IFN γ response. Our findings provide evidence of within-individual age-related declines in immune performance in a wild mammal and highlight the likely complexity of the mechanisms that generate them.


2018 ◽  
Author(s):  
Sil H. J. van Lieshout ◽  
Amanda Bretman ◽  
Chris Newman ◽  
Christina D. Buesching ◽  
David W. Macdonald ◽  
...  

Telomeres, protective caps at the end of chromosomes, maintain genomic stability and function as a biomarker of senescence in many vertebrate species. Telomere length at different ages has been related to (subsequent) lifespan, but to date only one laboratory-based study has shown a direct link between early-life telomere length and lifespan. Whether this relationship holds in wild populations, where individuals are subject to variable natural conditions that may mask relationships seen in controlled laboratory settings, remains unknown. Here, we provide evidence that early-life telomere length predicts survival to adulthood in a wild population of European badgers (Meles meles). Furthermore, both early-life telomere length and telomere rate of change predict lifespan. We found a complex cross-sectional relationship between telomere length and age, where telomeres shortened over the first 38 months, but with no uniform loss after this point. We found little within-individual consistency in telomere length across lifespan, where telomere length did not predict residual lifespan. Importantly, we also observed increases in mean telomere length within individuals, which could not be explained by measurement error alone. Early-life telomere length varied distinctly among cohorts, indicating a role for early-life environment and additive genetic effects. Our results elaborate on the dynamic way that telomeres function as a biomarker of senescence in a wild mammal, where telomere length and rate of change can reflect short-term and lasting effects of early-life conditions on individual life-history.


2021 ◽  
Author(s):  
Sil H.J. van Lieshout ◽  
Elisa P. Badás ◽  
Julius G. Bright Ross ◽  
Amanda Bretman ◽  
Chris Newman ◽  
...  

2021 ◽  
Author(s):  
Elizabeth L. Sheldon ◽  
Riccardo Ton ◽  
Winnie Boner ◽  
Pat Monaghan ◽  
Shirley Raveh ◽  
...  

Author(s):  
Antoine Stier ◽  
Bin-Yan Hsu ◽  
Coline Marciau ◽  
Blandine Doligez ◽  
Lars Gustafsson ◽  
...  

AbstractPrenatal environmental conditions can have lifelong consequences on health and aging. The underlying mechanisms remain nonetheless little understood. Thyroid hormones (THs) are important regulators of embryogenesis transferred from the mother to the embryo. In an avian model, we manipulated embryo exposure to maternal THs through egg injection and investigated the consequences on postnatal growth and aging. We first report that mitochondrial DNA (mtDNA) copy number and telomere length significantly decrease from early-life to late adulthood, thus confirming that these two molecular markers are hallmarks of aging in our wild bird model. The experimental elevation of prenatal THs levels had a transient positive effect on postnatal growth. Elevated prenatal THs had no effect on mtDNA copy number but significantly increased telomere length both soon after birth and at the end of the growth period (equivalent to offsetting ca. 4 years of post-growth telomere shortening). These findings suggest that prenatal THs have a key role in setting the ‘biological’ age at birth, and thus might influence longevity.


2021 ◽  
Author(s):  
Sophie Bennett ◽  
Antje Girndt ◽  
Alfredo Sánchez-Tójar ◽  
Terry Burke ◽  
Mirre J. P. Simons ◽  
...  

Offspring of older parents in many species display decreased longevity, a faster ageing rate and lower fecundity than offspring born to younger parents. Biomarkers, such as telomeres, that tend to shorten as individual age, may provide insight into the mechanisms of parental age effects. Parental age could determine telomere length either through inheritance of shortened telomeres or through indirect effects, such as variation in parental care with parent ages, which in turn might lead to variation in offspring telomere length. There is no current consensus as to the heritability of telomere length, and the direction and extent of parental age effects however. To address this, here we experimentally investigate how parental age is associated with telomere length at two time points in early life in a captive population of house sparrows (Passer domesticus). We experimentally separated parental age from sex effects by allowing the parent birds to only mate with young, or old partners. We found that telomere length of the offspring increased between the age of 0.5 and 3 months at the group and individual level, which has been reported previously predominantly in non-avian taxa. We further show that older fathers produced daughters with a greater early-life increase in telomere length, supporting sex-specific inheritance, and or sex-specific non-genetic effects. Overall, our results highlight the need for more studies testing early-life telomere dynamics and sex-specific heritability of telomere length.


2021 ◽  
Author(s):  
Michael Le Pepke ◽  
Thomas Kvalnes ◽  
Sarah Lundregan ◽  
Winnie Boner ◽  
Pat Monaghan ◽  
...  

Author(s):  
Michael Pepke ◽  
Thomas Kvalnes ◽  
Sarah Lundregan ◽  
Winnie Boner ◽  
Pat Monaghan ◽  
...  

Early-life telomere length (TL) is associated with fitness in a range of organisms. Little is known about the genetic basis of variation in TL in wild animal populations, but to understand the evolutionary and ecological significance of TL it is important to quantify the relative importance of genetic and environmental variation in TL. In this study, we measured TL in 2746 house sparrow nestlings sampled across 20 years and used an animal model to show that there is a small heritable component of early-life TL (h2=0.04), but with a strong component of maternal inheritance. Variation in TL among individuals was mainly driven by environmental (year) variance, but also brood and parental effects. We did not find evidence for a negative genetic correlation underlying the observed negative phenotypic correlation between TL and structural body size. Thus, TL may evolve independently of body size and the negative phenotypic correlation is likely to be caused by non-genetic environmental effects. We further used genome‐wide association analysis to identify genomic regions associated with TL variation. We identified several putative genes underlying TL variation; these have been inferred to be involved in oxidative stress, cellular growth, skeletal development, cell differentiation and tumorigenesis in other species. Together, our results show that TL is a lowly heritable, polygenic trait which is strongly affected by environmental conditions in a free-living bird.


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