Myoglobin (Mb), the intracellular oxygen carrier and storage protein of the heart, is highly conserved in all vertebrates and, because it is small and easy to crystallize, it was the first protein of known 3D structure. Mb is also a protein expressed at high levels, which gives the heart its bright red color. Surprisingly, the physiological role of Mb is not fully understood. However, the common view is that Mb is needed to sustain the high rates of mitochondrial respiration and ATP production in the heart.

With this project, we aim to study the consequences of deleDng Mb expression in the heart to understand the biological function of this protein. We have successfully generated Mb-knockout zebrafish lines lacking Mb gene expression that we now wish to compare with wild-type zebrafish. We will use a wide array of techniques to characterize the significance of Mb expression on several parameters at different levels of biological organization, including whole animal performance, metabolic rates and tolerance to hypoxia, heart metabolomics, mitochondrial function, ATP generation and key enzymatic activities. Experimental work is performed at the Department of Biology, Section of Zoophysiology, Aarhus University, in collaboration with the Department of Molecular Biology and Genetics, Aarhus University, and the Department of Biosciences, University of Oslo.