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Myofilament structure in muscle from tissue specific Bmal1 KO mice
Author(s) -
Houtz Jessica,
Campbell Kenneth,
Esser Karyn
Publication year - 2010
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.24.1_supplement.801.18
Subject(s) - myofilament , skeletal muscle , myosin , actin , anatomy , myocyte , sarcomere , muscle architecture , myofibril , muscle contraction , biology , chemistry , biophysics , microbiology and biotechnology , endocrinology
We have observed that skeletal muscle from the arrhythmic germline Bmal1 knock out mouse (Bmal1 KO) exhibits significant weakness defined by a reduction in muscle specific tension. Evaluation of electron micrographs (EMs) from cross‐sections of adult gastrocnemius muscles reveals obvious divergences from the normal hexagonal arrangement of thin and thick filaments in the Bmal1 KO mice. The objective of this project is to address whether the structural pathology in muscle is the result of local or systemic loss of Bmal1 . We have generated a striated muscle specific Bmal1 KO mouse and developed a computational tool for the quantitative analysis of myofilament architecture. Bmal1 is selectively eliminated in striated muscle by crossing the MCK‐Cre mouse with the floxed Bmal1 mouse. Muscle structure will be evaluated with newly developed image processing software that identifies bundles of actin (thin filaments) or myosin (thick filaments) in EMs of muscle cross‐sections. Preliminary programming detects myofilaments as intensity peaks in the gray‐scale image and categorizes them as thick or thin depending on the cross‐sectional area of the peaks. Cellular–level muscle function is assessed using permabilized single fiber mechanics. The results of this work will determine whether local muscle specific expression of Bmal1 is necessary for maintenance of adult skeletal muscle structure and function.