Last update: : Thursday 18 June 2015, by
Par : Jose C. Noguera, Institute of Biodiversity, Animal Health & Comparative Medicine. University of Glasgow
Date : Jeudi 8 octobre 2015 à 13h30
Lieu : IPHC, Amphithéâtre Grünewald, bâtiment 25
Loss and restoration of telomeres, the protective ends of eukaryotic chromosomes, play a key role in cellular death and replacement, and thereby in ageing. Most telomere loss occurs during early development, a life stage where organisms are exposed to a number of factors that can induce oxidative stress, an important factor contributing to telomere loss. It has recently been proposed that dietary antioxidants might play an important role in telomere protection. In birds, the protective effect of dietary antioxidants on telomeres might take place either during embryo development (i.e. via maternal allocation of antioxidants into the egg yolk) or during post-natal growth period (i.e. via parental feeding). In a series of experiments with zebra finches, we investigated
1) intra-clutch variation in maternally-derived dietary antioxidants and embryo telomere length,
2) whether within-clutch differences in embryo telomere length persist during post-natal development and
3) whether dietary antioxidants may help to prevent the loss of telomere length after hatching.
We found that the level of maternally-derived dietary antioxidants in the egg-yolk were markedly lower in the last compared to earlier laid eggs, resulting in shorter telomere length in the embryos. Interestingly, these differences in telomere length among siblings persisted until adulthood. In addition, by experimentally manipulating the intake of dietary antioxidants during post-natal development, we also found that females fed with a high antioxidant diet during sexual maturation showed reduced telomere loss. Together, these results indicate that dietary antioxidants can influence rates of cellular senescence during different stages of the development.