Rainbow trout display a developmental shift in red muscle kinetics, swimming kinematics and myosin heavy chain isoform |
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Authors: | D. J. Coughlin J. Burdick K. A. Stauffer F. E. Weaver |
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Affiliation: | Widener University, Department of Biology, One University Place, Chester, PA 19013, U.S.A. |
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Abstract: | Both activation and relaxation times of rainbow trout Oncorhynchus mykiss red muscle were shorter in parr than in older juveniles. Furthermore, parr red muscle had a faster maximum shortening velocity than that of older fish, as estimated with the force-clamp technique. Parr swam with higher tailbeat frequencies and lower tailbeat amplitude than did older fish across a range of length-specific steady swimming speeds. The developmental shift in contraction kinetics of red muscle and steady swimming kinematics was associated with a reduction from two or three myosin heavy chain isoforms in parr to one in older juveniles. This transition provides a mechanism to explain the variations in muscle contraction kinetics and swimming performance. |
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Keywords: | parr juvenile trout swimming behaviour smoltification SDS–PAGE |
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