Meeting Abstract
As part of mitonuclear communication, retrograde and anterograde signalling helps maintain homeostasis under basal conditions. Basal conditions, however, vary across phylogeny. At the cell-level, some mitonuclear retrograde responses can be quantified by measuring the constitutive components of oxidative stress, the balance between RS (reactive species), and antioxidants. RS are metabolic by-products produced by the mitochondria that can damage macromolecules by structurally altering proteins and inducing mutations in DNA, among other processes. To combat accumulating damage, organisms have evolved endogenous antioxidants and can consume exogenous antioxidants to sequester RS before they cause cellular damage. RS are also considered to be regulated through a retrograde signalling cascade from the mitochondria to the nucleus. These cellular pathways have may implications at the whole-animal level as well. For example, birds have higher basal metabolic rates, higher blood glucose concentration and longer lifespans than similar sized mammals, however, the literature is divergent on whether oxidative stress is higher in birds compared with mammals. Here, we review the literature and provide new data to answer whether whole-animal metabolic phenotypic traits between birds and mammals translate into the oxidative stress machinery. Because oxidative stress has been accepted by gerontologists as the common physiological mechanism that may cause aging, has also been the process implicated in differing life-history theories, and a determinant of growth rates in animals, this work has the potential to have broad implications.
