Data from: Mitochondrial function declines with age within individuals but is not linked to the pattern of growth or mortality risk in zebra finch

Mitochondrial dysfunction is considered a highly conserved hallmark of ageing. However, most studies in both model and non-model organisms are cross-sectional in design; therefore, little is known, at the individual level, on how mitochondrial function changes with age, its link to early developmental conditions or its relationship with survival. Here we manipulated the postnatal growth in zebra finches (Taeniopygia guttata) via dietary modification that induced accelerated growth without changing adult body size. In the same individuals, we examined blood cells mitochondrial functioning (mainly erythrocytes) when they were young (ca 36 weeks) and again in mid-aged (ca 91 weeks) adulthood. Mitochondrial function was strongly influenced by age but not by postnatal growth conditions. Across all groups, within individual ROUTINE respiration, OXPHOS and OXPHOS coupling efficiency significantly declined with age, while LEAK respiration increased. However, we found no link between mitochondrial function and the probability of survival into relatively old age (ca 4 years). Our results suggests that the association between accelerated growth and reduced longevity, evident in this as in other species, is not attributable to age-related changes in any of the measured mitochondrial function traits.Funding provided by: H2020 European Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/100010663Award Number: 101020037Funding provided by: Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko JaurlaritzaCrossref Funder Registry ID: http://dx.doi.org/10.13039/100015866Award Number: POS-2020-1-0007Funding provided by: Leverhulme TrustCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000275Award Number: RPG-2017-061Funding provided by: Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko JaurlaritzaCrossref Funder Registry ID: http://dx.doi.org/10.13039/100015866Award Number: POS‐2020‐1‐0007Funding provided by: Leverhulme TrustCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000275Award Number: RPG‐2017‐061Mitochondrial respiration in intact RBCs (Red Blood Cell) was performed using a modification of previously described methods for intact fresh avian red blood cells, RBCs (Dawson & Salmón 2020; Stier et al. 2017)