Red blood cells open promising avenues for longitudinal studies of ageing in laboratory, non-model and wild animals

International audienceAgeing is characterized by a progressive deterioration of multiple physiological and molecular pathways, whichimpair organismal performance and increase risks of deathwith advancing age.Hence, ageing studies must identifyphysiological and molecular pathways that showsigns of age-related deterioration, and test their associationwith the risk of death and longevity. This approach necessitates longitudinal sampling of the same individuals,and therefore requires a minimally invasive sampling technique that provides access to the larger spectrum ofphysiological and molecular pathways that are putatively associated with ageing. The present paper underlinesthe interest in using red blood cells (RBCs) as a promising target for longitudinal studies of ageing in vertebrates.RBCs provide valuable information on the following six pathways: cell maintenance and turnover (RBC number,size, and heterogeneity), glucose homeostasis (RBC glycated haemoglobin), oxidative stress parameters, membranecomposition and integrity, mitochondrial functioning, and telomere dynamics. The last two pathwaysare specific to RBCs of non-mammalian species, which possess a nucleus and functional mitochondria. Wepresent the current knowledge about RBCs and age-dependent changes in these pathways in non-model andwild species that are especially suitable to address questions related to ageing using longitudinal studies. Wediscuss how the different pathways relate with survival and lifespan and give information on their genetic andenvironmental determinants to appraise their evolutionary potential