Sex specific data from The relationship between telomere length and mortality risk in non-model vertebrate systems: a meta-analysis

Telomere length (TL) has become a biomarker of increasing interest within ecology and evolutionary biology, and has been found to predict subsequent survival in some recent avian studies but not others. Here, we undertake the first formal meta-analysis to test whether there is an overall association between TL and subsequent mortality risk in vertebrates other than humans and model laboratory rodents. We identified 27 suitable studies and obtained standardized estimates of the hazard ratio associated with TL from each. We performed a meta-analysis on these estimates and found an overall significant negative association implying that short telomeres are associated with increased mortality risk, which was robust to evident publication bias. While we found that heterogeneity in the hazard ratios was not explained by sex, follow-up period, maximum lifespan or the age group of the study animals, the TL–mortality risk association was stronger in studies using qPCR compared to terminal restriction fragment methodologies. Our results provide support for a consistent association between short telomeres and increased mortality risk in birds, but also highlight the need for more research into non-avian vertebrates and the reasons why different telomere measurement methods may yield different results.This article is part of the theme issue ‘Understanding diversity in telomere dynamics’

International journal of forest engineering

R script used to calculate hazard ratio

Supplementary Table 1 from The relationship between telomere length and mortality risk in non-model vertebrate systems: a meta-analysis

List of studies assess for eligibility in full, with reasons for exclusio

Heritability estimate of RLTL by month of age; standard errors in dotted lines (SE = 0.045–0.078).

<p>Heritability estimate of RLTL by month of age; standard errors in dotted lines (SE = 0.045–0.078).</p

Fixed curve of logarithmically transformed relative leukocyte telomere (RLTL) data.

<p>Blue line: quadratic Legendre polynomial function of age; black solid line: phenotypic RLTL measurements for each month.</p

Individual RLTL profiles (grey) and five cluster curves.

<p>Of all animals 31% shortened their RLTL slightly in early life (red curve), 30% maintained their RLTL over life (green curve), 22% showed mild elongation in early life (blue curve), 12% more obvious elongation (pink curve) and 4% more obvious telomere attrition (cyan curve).</p

Genetic correlation of RLTL measurements at birth with measurements in later life.

<p>standard errors in dotted lines (maximal SE = 0.087).</p

Survival probability of different RLTL profile cluster groups.

<p>Colours correspond to colours in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192864#pone.0192864.g005" target="_blank">Fig 5</a>.</p