Krympande telomerer: orsaker och verkan

Current research on telomeres, the non-coding DNA-protein ‘caps’ at the end of chromosomes, shows some intriguing relationships between their attrition (´shortening´) and important components of fitness; in our model system, the sand lizard (Lacerta agilis), embryos that grow faster have shorter telomeres, those that die in incubation have shorter telomeres than hatchlings, and hatchlings with longer telomeres are more likely to become recruited into the breeding population.

Adult females have longer telomeres than males and female lifetime reproductive success is predicted by telomere length. In both sexes, climatic extremes, warmer summers and colder winters, results in more profound telomere attrition. What may explain these relationships?

The ´metabolic rate attrition´ hypothesis suggests a causal effect of telomere length and attrition, with glucocorticoids during stress changing metabolism and resources available for telomere maintenance.

An alternative is that telomeres are biomarkers and that important links to suboptimal development and inviability may be through oxidative stress or epigenetic, temperature-dependent DNA methylation (DNAm), which would explain the climatic effects on attrition.

I outline a 4-year program using a model system with extensive background information to test between these hypotheses of telomere attrition and its dynamics. My laboratory at U. Gothenburg have all the necessary molecular end physiological equipment for the proposed project.