title: The zebrafish myotome contains tonic muscle fibers: morphological characterization and time course of formation.
abstract: It is long known that the skeletal muscle of teleost fish contains muscle fibers which are in all probability of a tonic type according to morphological criteria. However, the evidence for the existence of teleost tonic fibers is still confined to a very small number of species, and knowledge concerning their ontogeny and possible functions is even more restricted. A remarkable deficit in this context is that it is not even exactly known whether the zebrafish, which is widely used to study vertebrate developmental biology, has such fibers, or how they arise. The present study demonstrates the existence of tonic fibers in the zebrafish myotome. They are identical with a fiber population previously termed "red muscle rim" fibers. A combined histochemical, immunocytochemical, and ultrastructural approach is used to characterize the morphology and development of these fibers. This study provides a basis for using the zebrafish model system in the future research on the developmental regulation and the functions of tonic fibers.
authors.affiliation: Department of Organismic Biology, Division of Zoology and Functional Anatomy, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria. julia.marschallinger@stud.sbg.ac.at
authors.forename: Julia
authors.initials: J
authors.lastname: Marschallinger
authors.forename: Astrid
authors.initials: A
authors.lastname: Obermayer
authors.forename: Peter
authors.initials: P
authors.lastname: Steinbacher
authors.forename: Walter
authors.initials: W
authors.lastname: Stoiber
mesh_terms: D000818:Animals; D007814:Larva / Q000033:anatomy & histology; D024510:Muscle Development / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000254:growth & development*; D060726:Torso; D015027:Zebrafish / Q000033:anatomy & histology*