title: Myosin heavy chain 2B isoform is expressed in specialized eye muscles but not in trunk and limb muscles of cattle.
abstract: Myosin heavy chain isoforms (MHC) of adult skeletal muscles are codified by four genes named: slow, or type 1, and fast types 2A, 2X and 2B. The slow, 2A and 2X isoforms have been found expressed in all mammalian species studied so far whereas there is a large inter-species variability in the expression of MHC-2B. In this study histochemistry (m-ATPase), immunohistochemistry with the use of specific monoclonal antibodies and RT-PCR were combined together to assess whether the MHC-2B gene is expressed in bovine muscles. ATPase staining and RT-PCR experiments showed that three MHC isoforms (1, 2A, 2X) were expressed in trunk and limb muscles. Slow or type 1 expression was confirmed using a specific antibody (BA-F8) whereas the detection of fast MHC isoforms were validate by means of BF-35 antibody although not by the SC-71 antibody. MHC-2B was absent in limb and trunk muscles, but was present in specialized eye muscles (rectus lateralis and retractor bulbi) as consistently showed by RT-PCR and reactivity with a specific antibody (BF-F3). Interestingly, a cardiac isoform, MHC-a-cardiac was found to be expressed not only in extraocular muscles but also in masticatory muscles as masseter.
authors.affiliation: Department of Experimental Veterinary Sciences, University of Padua, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Maccatrozzo
authors.forename: M
authors.initials: M
authors.lastname: Patruno
authors.forename: L
authors.initials: L
authors.lastname: Toniolo
authors.forename: C
authors.initials: C
authors.lastname: Reggiani
authors.forename: F
authors.initials: F
authors.lastname: Mascarello
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle / Q000235:genetics / Q000378:metabolism*; D006651:Histocytochemistry; D007120:Immunochemistry; D008969:Molecular Sequence Data; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D009801:Oculomotor Muscles / Q000378:metabolism*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D024744:Skeletal Muscle Myosins / Q000235:genetics / Q000378:metabolism*
chemical_list: D024744:Skeletal Muscle Myosins; D018995:Myosin Heavy Chains