Widespread episodic thiamine deficiency in Northern Hemisphere wildlife
Authors: Lennart Balk, Per-Åke Hägerroth, Hanna Gustavsson, Lisa Sigg, Gun Åkerman, Yolanda Ruiz Muñoz, Dale C. Honeyfield, Ulla Tjärnlund, Kenneth Oliveira, Karin Ström, Stephen D. McCormick, Simon Karlsson, Marika Ström, Mathijs van Manen, Anna-Lena Berg, Halldór P. Halldórsson, Jennie Strömquist, Tracy K. Collier, Hans Börjeson, Torsten Mörner & Tomas Hansson
Source: Scientific Reports 6, Article number: 38821 (2016) doi:10.1038/srep38821
Abstract: Many wildlife populations are declining at rates higher than can be explained by known threats to biodiversity. Recently, thiamine (vitamin B1) deficiency has emerged as a possible contributing cause. Here, thiamine status was systematically investigated in three animal classes: bivalves, ray-finned fishes, and birds. Thiamine diphosphate is required as a cofactor in at least five life-sustaining enzymes that are required for basic cellular metabolism. Analysis of different phosphorylated forms of thiamine, as well as of activities and amount of holoenzyme and apoenzyme forms of thiamine-dependent enzymes, revealed episodically occurring thiamine deficiency in all three animal classes. These biochemical effects were also linked to secondary effects on growth, condition, liver size, blood chemistry and composition, histopathology, swimming behaviour and endurance, parasite infestation, and reproduction. It is unlikely that the thiamine deficiency is caused by impaired phosphorylation within the cells. Rather, the results point towards insufficient amounts of thiamine in the food. By investigating a large geographic area, by extending the focus from lethal to sublethal thiamine deficiency, and by linking biochemical alterations to secondary effects, we demonstrate that the problem of thiamine deficiency is considerably more widespread and severe than previously reported.
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