Invertebrates Mitochondrial Function and Energetic Challenges

Warm-preconditioning protects against acute heat-induced respiratory dysfunction and delays bleaching in a symbiotic sea anemone

“…Aerobic respiration is critical to metazoan physiology and is highly sensitive to the abiotic environment (Somero and Hochachka, 2002;Clarke, 2003;Martinez-Cruz et al, 2012). In symbiotic cnidarians such as E. pallida and reef corals, regulation of aerobic respiration could be important in determining their sensitivity to ocean warming (Dunn et al, 2012;Dixon et al, 2015;Lutz et al, 2015;Jin et al, 2016).…”

“…First, we hypothesised that -as for many marine ectotherms undergoing warm acclimation Pörtner, 1999, 2004;Martinez-Cruz et al, 2012;Chung and Schulte, 2015) -preconditioning of E. pallida and its Symbiodinium correlates with declining mitochondrial density/ aerobic capacity. Second, we hypothesised that preconditioning has a measurable influence on the acute heating response of host and symbiont mitochondrial respiration, and protects against excessive superoxide generation and thermal bleaching.…”

“…The TCA cycle progressively oxidises glycolysis-derived carbon-rich substrates and transfers their electrons to NAD + and FAD (Berg et al, 2002;Somero and Hochachka, 2002). While oxygen is not directly involved, the TCA cycle is dependent on regeneration of NAD + and FAD by the mitochondrial electron transport chain (mETC) where O 2 is the terminal electron acceptor (Berg et al, 2002;Martinez-Cruz et al, 2012). With the TCA cycle acting as the 'hub' of cellular aerobic metabolism (Somero and Hochachka, 2002), biomass-normalised activity of its gate-keeper enzyme citrate synthase (CS) is a useful marker of tissue mitochondrial density and aerobic capacity (e.g.…”

Weight of evidence evaluation of a network of adverse outcome pathways linking activation of the nicotinic acetylcholine receptor in honey bees to colony death

“…Although the proposed relationship between mitochondrial dysfunction and impaired hive thermoregulation appears highly plausible, there is a lack of empirical evidence directly exploring this relationship (Martinez-Cruz et al, 2012;Southwick and Heldmaier, 1987). Therefore, the WoE for the KER was designated as 'weak.'…”

Adverse Outcome Pathway on binding of agonists to ionotropic glutamate receptors in adult brain leading to excitotoxicity that mediates neuronal cell death, contributing to learning and memory impairment

“…Many invertebrate species (drosophila, C. elegans) are considered as potential models to study mitochondrial function (Sanchez-Paz et al, 2012;Tahira and Farooqui, 2012). New data on marine invertebrates, such as molluscs and crustaceans and non-Drosophila species, are emerging (Martinez-Cruz, 2012). Mitochondrial dysfunction can be measured in animal models used for toxicity testing (Winklhofer and Haass, 2010;Waerzeggers et al, 2010) as well as in humans (Winklhofer and Haass, 2010).…”