caa a22 4500 475744896 CHVBK 20180406123510.0 cr unu---uuuuu 170329e20001001xx s 000 0 eng 10.1023/A:1005676106940 doi (NATIONALLICENCE)springer-10.1023/A:1005676106940 Jaw-closing muscles of kangaroos express α-cardiac myosin heavy chain [Elektronische Daten] [Joseph Hoh, Yoonah Kim, Louise Sieber, Wendy Zhong, Christine Lucas] The masseter muscle of eutherian grazing mammals typically express β or slow myosin heavy chain (MyHC). Myosins in the masseter of 4 species of kangaroos and a slow limb muscle of one of them were compared with their cardiac myosin by pyrophosphate and sodium dodecyl sulphate (SDS) gel electrophoresis, immunoblotting and immunohistochemistry. It was found that ventricular muscle contains three isoforms homologous to V1 (α-MyHC homodimer), V2 (heterodimer) and V3 (β-MyHC homodimer) of eutherian cardiac muscle, and that the masseter contained V1, with traces of V2 and V3, in great contrast to eutherian ruminants, which express only V3. A polyclonal antibody (anti-KJM) was raised in rabbits against red kangaroo masseter myosin. After cross-absorption against limb muscle myofibrils, anti-KJM specifically reacted in Westerns with MyHCs from masseter but not limb muscles, and immunohistochemically with masseter, but not limb muscle fibers. In pyrophosphate Western blots, anti-KJM reacted with V1 but not with V3. However, a monoclonal antibody specific for eutherian slow myosin stained all kangaroo slow muscle fibers but only weakly stained scattered fibers in the masseter. The SDS-PAGE revealed that light chain composition of masseter and ventricular myosins is identical, but isoforms of both light chains of kangaroo limb slow myosin were observed. These results confirm that kangaroo jaw muscle express α-MyHC rather than β-MyHC. The difference in MyHC gene expression between marsupial and eutherian grazers may be related to the fact that kangaroos are not ruminants, and have only a single chance to comminute food into fine particles, hence the need for the greater speed and power of muscle contraction associated with V1 containing muscle fibers. Kluwer Academic Publishers, 2000 Hoh Joseph Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut Kim Yoonah Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut Sieber Louise Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut Zhong Wendy Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut Lucas Christine Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/7(2000-10-01), 673-680 0142-4319 21:7<673 2000 21 10974 https://doi.org/10.1023/A:1005676106940 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1005676106940 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hoh Joseph Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut NATIONALLICENCE 700 1- Kim Yoonah Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut NATIONALLICENCE 700 1- Sieber Louise Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut NATIONALLICENCE 700 1- Zhong Wendy Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut NATIONALLICENCE 700 1- Lucas Christine Department of Physiology and Institute for Biomedical Research, F13, The University of Sydney, 2006, NSW, Australia aut NATIONALLICENCE 773 0- Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/7(2000-10-01), 673-680 0142-4319 21:7<673 2000 21 10974 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer