title: Presence of an unidentified myosin isoform in certain bovine foetal muscles.
abstract: Genetic variation in the establishment of bovine muscle fibre types was studied by comparing muscle differentiation at 210 days of foetal life in normal cattle and in 'culard' animals, which have muscular hypertrophy. The different fibre types were determined by histochemical and immunohistochemical analyses with monoclonal antibodies specific to different myosin heavy chain isoforms. The isoforms were separated by electrophoresis and quantified by the ELISA method. Four muscles with different contractile and metabolic characteristics were studied: Semitendinosus, Longissimus thoracis, Masseter (slow) and Cutaneus trunci (fast). Muscle fibres recognized by none of the antibodies used were observed in 'culard' foetuses in all the muscles studied and also in the Cutaneus trunci of normal animals. Electrophoretic analysis showed no particular myosin isoform in these muscles. It is possible therefore that the fibres contained a mysosin isoform until now unidentified in cattle, with a molecular weight the same as that of known isoforms. This newly observed isoform seems to be specific to muscles rich in IIB fibres such as Cutaneus trunci and to the muscles of adult 'culard' cattle.
authors: INRA-Centre de Clermont-Fd/Theix, Laboratoire Croissance et Métabolismes des Herbivores, Theix, St. Genes-Champanelle, 63122 France.
authors: B
authors: B
authors: Picard
authors: H
authors: H
authors: Gagnière
authors: J
authors: J
authors: Robelin
authors: F
authors: F
authors: Pons
authors: Y
authors: Y
authors: Geay