High growth rate is associated with a short lifespan, but the physiological basis for this trade-off is not well known. Telomere length predicts individual lifespan and in this study we investigated whether embryonic growth rate, manipulated using incubation temperature, affects erythrocyte telomere length in a wild bird species, the common tern (). A 1°C lower incubation temperature decreased growth rate by 5%, without affecting size at hatching. The slower growth was associated with an average telomere length that was 147 base pairs longer at hatching. If carried through to adulthood, this effect would correspond with an approximately 3 year longer lifespan. Our results thus suggest that an effect of growth rate on lifespan may be mediated by telomere dynamics or a physiological process reflected by telomere length.

Genetic factors and early life developmental conditions affect growth, with long-term consequences for adult health and fitness, but the underlying proximate mechanisms remain elusive (Dmitriew, 2011). Biomarker variables could shed light on causal mechanisms, in particular when manipulated growth rate is reflected in the biomarker and when the biomarker variable in turn is predictive of

HMGB1 release is increased in the skin of SLE patients compared to HCs. Upon UVB exposure, HMGB1 release further increases in SLE patients and is related to the number of apoptotic cells. Our data suggest that HMGB1, probably released from apoptotic keratinocytes, contributes to the development of inflammatory lesions in the skin of SLE patients upon UVB exposure.

Birds exposed to food insecurity—defined as temporally variable access to food—respond adaptively by storing more energy. To do this, they may reduce energy allocation to other functions such as somatic maintenance and repair. To investigate this trade-off, we exposed juvenile European starlings ( Sturnus vulgaris , n = 69) to 19 weeks of either uninterrupted food availability or a regime where food was unpredictably unavailable for a 5-h period on 5 days each week. Our measures of energy storage were mass and fat scores. Our measures of somatic maintenance were the growth rate of a plucked feather, and erythrocyte telomere length (TL), measured by analysis of the terminal restriction fragment. The insecure birds were heavier than the controls, by an amount that varied over time. They also had higher fat scores. We found no evidence that they consumed more food overall, though our food consumption data were incomplete. Plucked feathers regrew more slowly in the insecure birds. TL was reduced in the insecure birds, specifically, in the longer percentiles of the within-individual TL distribution. We conclude that increased energy storage in response to food insecurity is achieved at the expense of investment in somatic maintenance and repair.