Differences in locomotor performance between individuals: importance of parvalbumin, calcium handling and metabolism

Abstract

SUMMARYLocomotor performance is linked to fitness and health of animals and is expected to be under strong selection. However, interindividual variation in locomotor performance is pronounced in many species. It was our aim to investigate the relative importance of energy metabolism and calcium handling in determining sprint and sustained locomotion in the zebrafish (Danio rerio). Sprint and sustained performance (U crit ) varied independently from each other. Using in vivo electroporation, we found that increased parvalbumin protein concentration improved both sprint and sustained locomotion. This is the first demonstration that parvalbumin plays a role in determining whole-animal performance. High sprint performance fish had greater mRNA concentrations of the metabolic regulators PPAR and PGC1 compared with fish with poor sprint performance. High sustained performance fish, in contrast, had greater concentrations of PGC-1 and PGC-1. The increased expression of these metabolic regulators indicates an enhancement of the metabolic machinery in high performance animals. Sprint performance is also enhanced by creatine kinase activity, which may be associated with increased PPAR mRNA concentration. Ryanodine receptor (RyR) and sarcoplasmic reticulum Ca 2+ -ATPase 1 (SERCA1) mRNA concentrations were significantly increased in high sustained performance fish, while parvalbumin 2, dihydropyridine (DHPR) receptor and SERCA2 mRNA levels were increased in fish with high sprint velocities. Sustained performance was more sensitive to experimentally induced decreases in RyR and DHPR activity than sprint performance. We provide mechanistic explanations of why locomotor performance differs between individuals, which is important for understanding ecological and sporting success, disease and the evolutionary processes underlying selection.

Living in flowing water increases resistance to ultraviolet B radiation

“…Fast release of calcium from the sarcoplasmic reticulum increases force production but decreases fatigue resistance . Increased rates of resequestration of calcium into the sarcoplasmic reticulum by the sarco(endo)plasmic reticulum ATPase (SERCA) improves both sprint and sustained locomotion (Seebacher and Walter, 2012). ROS can interfere with calcium release dynamics from the sarcoplasmic reticulum and the calcium sensitivity of troponin (Cheng et al, 2016).…”

Resurrecting prehistoric parvalbumins to explore the evolution of thermal compensation in extant Antarctic fish parvalbumins

“…In white muscle this increase in PV Ca 2+ affinity would disrupt the correct timing of muscle contraction by diverting Ca 2+ from binding to troponin C, which presumably could put fish at a disadvantage when trying to feed on swimming prey or when evading predators. Indeed, it has recently been shown that zebrafish swimming performance is correlated with PV content (Seebacher and Walter, 2012), indicating a role of PV in ecological fitness of teleost fish. For Antarctic fish PVs to function optimally we would expect to find evolutionary substitutions of amino acid residues compensating for the decreased ambient temperature.…”

Determining environmental causes of biological effects: the need for a mechanistic physiological dimension in conservation biology

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