title: Myosin isoforms and fibre types in limb muscles of Australian marsupials: adaptations to hopping and non-hopping locomotion.
abstract: Using immunohistochemistry and SDS-PAGE, we studied the myosin heavy chain (MyHC) composition and fibre type distribution of hindlimb muscles of hopping and non-hopping Australian marsupials. We showed that hindlimb muscles of a bandicoot (Isoodon obesulus, order Peramelomorphia) and a small macropodoid, the brushtail bettong (Bettongia penicillata) expressed four MyHCs, slow, 2a, 2x and 2b, and had the corresponding fibre types as other macropods reported earlier. The fastest and most powerful 2b fibres predominated in most bettong hindlimb muscles, but were absent in the gastrocnemius and the flexor digitorum profundus, which are involved in elastic strain energy saving during hopping. The gastrocnemius of four large macropodids also showed little or no 2b MyHC, whereas this isoform was abundant in their tibialis anterior, which is not involved in elastic energy saving. In contrast, 2b MyHC predominated in the gastrocnemius of four non-hopping marsupials. These results suggest that absence of 2b fibres may be a general feature of macropodoid muscles involved in elastic energy saving. Large eutherians except llamas and pigs also have no 2b fibres. We hypothesize that 2x and 2a fibres perform better than 2b fibres in the storage and recovery of kinetic energy during locomotion in both marsupials and eutherians.
authors: Faculty of Medicine, The University of Sydney, Sydney, NSW, 2006, Australia.
authors: Wendy W H
authors: WW
authors: Zhong
authors: Christine A
authors: CA
authors: Lucas
authors: Joseph F Y
authors: JF
authors: Hoh
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D004548:Elasticity; D004591:Electrophoresis, Polyacrylamide Gel; D006614:Hindlimb; D007150:Immunohistochemistry; D008124:Locomotion; D007614:Macropodidae / Q000378:metabolism; D008394:Marsupialia / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000737:chemistry*; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000166:cytology; D018995:Myosin Heavy Chains / Q000032:analysis*; D020033:Protein Isoforms
chemical_list: D020033:Protein Isoforms; D018995:Myosin Heavy Chains
references: Eur J Histochem. 2004 Oct-Dec;48(4):357-66
references: 15718201
references: J Exp Biol. 2004 May;207(Pt 11):1875-86
references: 15107442
references: Am J Physiol. 1992 May;262(5 Pt 2):R771-8
references: 1590472
references: J Physiol. 2003 Apr 15;548(Pt 2):461-74
references: 12598584
references: J Histochem Cytochem. 2001 Aug;49(8):1033-44
references: 11457931
references: J Comp Physiol B. 2003 Sep;173(7):549-57
references: 12905005
references: J Appl Physiol (1985). 1993 Nov;75(5):2337-40
references: 8307894
references: J Physiol. 1994 Dec 15;481 ( Pt 3):663-75
references: 7707234
references: Biochem Biophys Res Commun. 2000 May 27;272(1):303-8
references: 10872844
references: J Exp Biol. 1998 Jun;201(Pt 11):1681-94
references: 9576879
references: J Physiol. 1990 Dec;431:141-71
references: 2100305
references: Electrophoresis. 2001 Apr;22(6):1016-20
references: 11358122
references: Comp Biochem Physiol B Biochem Mol Biol. 1998 May;120(1):73-87
references: 9787779
references: J Histochem Cytochem. 2002 May;50(5):719-30
references: 11967283
references: J Muscle Res Cell Motil. 1999 Feb;20(2):211-21
references: 10412092
references: J Histochem Cytochem. 1993 May;41(5):733-43
references: 8468455
references: J Physiol. 1988 May;399:81-92
references: 3404473
references: Mamm Genome. 1998 Dec;9(12):1056-8
references: 9880677
references: Eur J Biochem. 1989 Dec 22;186(3):749-54
references: 2606114
references: J Exp Zool. 1996 Aug 15;275(6):413-20
references: 8795286
references: Anat Rec. 1998 Aug;251(4):548-62
references: 9713989
references: Science. 1964 Jun 26;144(3626):1577-8
references: 14169343
references: J Histochem Cytochem. 1990 Feb;38(2):257-65
references: 2137154
references: Am J Physiol. 1994 Dec;267(6 Pt 1):C1723-8
references: 7545970
references: J Muscle Res Cell Motil. 1989 Jun;10(3):197-205
references: 2547831
references: Curr Opin Rheumatol. 1992 Dec;4(6):801-8
references: 1457274
references: FEBS Lett. 1988 Aug 1;235(1-2):153-5
references: 3402594
references: J Physiol. 1991 Jun;437:655-72
references: 1890654
references: Anat Rec. 2001 Nov 1;264(3):284-93
references: 11596010
references: Physiol Biochem Zool. 2000 Nov-Dec;73(6):726-35
references: 11121346
references: J Muscle Res Cell Motil. 1995 Feb;16(1):35-43
references: 7751403