ISSN:
1432-0878
Keywords:
Fibrillogenesis
;
Muscle, cardiac
;
Myosin
;
Actin
;
Immunofluorescence microscopy
;
Myofibrils
;
Domestic fowl
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Myofibrillogenesis was studied in cultured chick cardiomyocytes using indirect immunofluorescence microscopy and antibodies against α- and γ-actin, muscle and nonmuscle tropomyosin, muscle myosin, and titin. Initially, cardiomyocytes, devoid of myofibrils, developed variable numbers of stress fiber-like structures with uniform staining for anti-muscle and nonmuscle actin and tropomyosin, and diffuse, weak staining with anti-titin. Anti-myosin labeled bundles of filaments that exhibited variable degrees of association with the stress fiber-like structures. Myofibrillogenesis occurred with a progressive, and generally simultaneous, longitudinal reorganization of stress fiber-like structures to form primitive sarcomeric units. Titin appeared to attain its mature pattern before the other major contractile proteins. Changes in the staining patterns of actin, tropomyosin, and myosin as myofibrils matured were interpreted as due to longitudinal filament alignment occurring before ordering in the axial direction. Non-muscle actin and tropomyosin were found with sarcomeric periodicity in the initial stages of sarcomere myofibrillogenesis, although their staining patterns were not identical. The localization of the “sarcomeric” proteins α-actin and muscle tropomyosin in stress fiber-like structures and the incorporation of non-muscle proteins in the initial stages of sarcomere organization bring into question the meaning of “sarcomeric” proteins in regard to myofibrillogenesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00327276
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