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Pax3 expression by satellite cells of avian skeletal muscle spindles
Author(s) -
Kirkpatrick Lisa J,
Rosser Benjamin WC
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.467.1
Subject(s) - myf5 , myogenesis , pax3 , myosin , biology , microbiology and biotechnology , immunohistochemistry , skeletal muscle , embryonic stem cell , muscle spindle , anatomy , myod , immunology , transcription factor , gene , biochemistry , afferent
Pax3 protein is usually co‐expressed with Pax7 by embryonic dermomyotome cells which give rise to skeletal muscle fibers. Following myogenesis, it is held that Pax3 expression becomes restricted to a few satellite cells (SCs) of select mature muscles. Intrafusal fibers of muscle spindles are thought to persist in an immature state as, unlike extrafusal fibers, they maintain small diameters, developmental myosins, Myf5 expression and high concentrations of SCs. Thus, we hypothesize that Pax3 expression is maintained in intrafusal fibers. Immunohistochemical methods were used to quantify nuclear numbers in chicken anterior latissimus dorsi muscles excised at 9, 30, 62, and 138 days post‐hatch. SCs were identified by their Pax7 expression. In intrafusal fibers, the percentage of SCs expressing Pax3 decreased from 76% at 9 days to 16% at 138 days post‐hatch and, at each age studied, was higher in intrafusal than extrafusal fibers. In extrafusal fibers, after 14% at 9 days, only 0‐2% of SCs expressed Pax3. Muscle spindles offer a novel model for the study of Pax3 expression in SCs. Funded by the Natural Sciences and Engineering Research Council of Canada. Grant Funding Source NSERC