The tarnished silver spoon? Trade-off between prenatal growth and telomere length in wild boar

Abstract

Life-history theory predicts a trade-off between growth rates and lifespan, which is reflected by telomere length, a biomarker of somatic state. We investigated the correlation between telomere length and early-life growth of wild boar piglets, Sus scrofa, kept under semi-natural conditions with high food availability to examine our hypothesis that increased pre- and postnatal growth will lead to telomere length attrition, but that a high supply of nutrient may provide the possibility to compensate telomere loss via telomere repair mechanisms. As predicted, our data showed a clear negative correlation between birth body mass and initial telomere length: heavier neonates had shorter telomeres at birth, and we did not find an influence of the mother on initial telomere length. Body mass at birth correlated with body mass later in life and postnatal growth rate did not affect telomere length. We observed an increase in telomere length during postnatal development, suggesting that high food availability allowed piglets to invest into both, growth and telomere restoration. The increase in telomere length over the duration of the study was not accompanied by telomerase activity; thus, telomere elongation was caused either by alternative mechanisms or by short pulses of telomerase activity that we missed. Taken together, this study suggests a trade-off between investment into growth and telomere maintenance even before birth and the possibility to compensate telomere attrition during growth under high amounts of available energy.

Keywords: Sus scrofa; early life; life history; prenatal growth; somatic maintenance; telomere attrition; trade-off.

FIGURE 1

Relationship between body mass at birth and body mass in five‐ to 127‐day‐old wild boar piglets (Sus scrofa). Females depicted in red, males in blue. Raw data with model predicted relationship shown. Grey area indicating standard error. Statistics were corrected for repeated measurements. Piglets with a higher birth body mass also showed higher body mass at later sampling points (day 5 to day 127) (χ² = 5.54, df = 1, p = 0.02, R ² m = 0.92, R ² c = 0.95, N = 24, n = 104)

FIGURE 2

Relationship between initial RTL (ie relative telomere length) and body mass of wild boar piglets (Sus scrofa) at birth. Females depicted in red, males in blue. There was a negative effect of body mass at birth on initial RTL (χ² = 5.02, df = 1, p = 0.03, R ² m = 0.21, R ² c = 0.21, N = 20). Raw data with model predicted relationship shown. Grey area indicating standard error

FIGURE 3

Relationship between RTL (ie relative telomere length; sampling points between day 5 and day 127) and birth body mass of wild boar piglets (Sus scrofa). The figure shows 81 data points from 19 individuals, females depicted in red, males in blue. There was a negative effect of high birth mass on RTL over the whole sampling period(χ² = 14.81, df = 1, p < 0.001, R ² m = 0.33, R ² c = 0.4, N = 19, n = 81). Statistics were corrected for repeated measurements. ‘Mother’ was included as random effect and ‘ID’ as nested random effect. Raw data with model predicted relationship shown. Grey area indicating standard error