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Within-individual repeatability in telomere length: a meta-analysis in non-mammalian vertebrates
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  • Tiia Kärkkäinen,
  • Michael Briga,
  • Toni Laaksonen,
  • Antoine Stier
Tiia Kärkkäinen
University of Turku
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Michael Briga
University of Turku
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Toni Laaksonen
University of Turku
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Antoine Stier
University of Turku
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Abstract

Telomere length is increasingly used as a biomarker of long-term life history costs, ageing and future survival prospects. Yet, to have the potential to predict long-term outcomes, telomere length should exhibit a relatively high within-individual repeatability over time, which has been largely overlooked in past studies. To fill this gap, we conducted a meta-analysis on 74 studies reporting longitudinal telomere length assessment in non-mammalian vertebrates, with the aim to establish the current pattern of within-individual repeatability in telomere length and to identify the methodological (e.g. qPCR/TRF, study length) and biological factors (e.g. taxon, wild/captive, age class, species lifespan, phylogeny) that may affect it. While the median within-individual repeatability of telomere length was moderate to high (R = 0.55; 95% CI: 0.05-0.95; N = 82), marked heterogeneity between studies was evident. Measurement method affected strongly repeatability estimate, with TRF-based studies exhibiting high repeatability (R = 0.80; 95% CI: 0.34-0.96; N = 25), while repeatability of qPCR-based studies was only half of that and more variable (R = 0.46; 95% CI: 0.04-0.82; N = 57). While phylogeny explained some variance in repeatability, phylogenetic signal was not significant (λ = 0.32; 95% CI: 0.00-0.83). None of the biological factors investigated here had a statistically significant association with the repeatability of telomere length, being potentially obscured by methodological noise. Our meta-analysis highlights the need to carefully evaluate and consider within-individual repeatability in telomere studies to ensure the robustness of using telomere length as a biomarker of long-term survival and fitness prospects.

Peer review status:IN REVISION

14 Jan 2021Submitted to Molecular Ecology
15 Jan 2021Assigned to Editor
15 Jan 2021Submission Checks Completed
24 Jan 2021Reviewer(s) Assigned
08 Apr 2021Review(s) Completed, Editorial Evaluation Pending
27 Apr 2021Editorial Decision: Revise Minor