ISSN:
1615-6102
Keywords:
Myotendinous junction
;
Dense bands
;
Lebistes reticulates
;
Myomyous junction
;
HMM decoration
;
Ca2+-activated protease
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Guppy muscle shows unique electron dense bands in the terminal segment of the myofibril at the muscle—tendon junction. On occasion electron dense bands were also observed at the myomyous junction. The unusual bands are approximately 70 nm wide with an electron density similar to that of Z-lines. Thin filaments seem to be continuous throughout these dense bands with no interdigitation of filaments before the membrane. Calcium-activated neutral protease removes the dense bands. The filaments of the terminal segment are decorated by heavy meromyosin and therefore are actin. The polarity of actin filaments, determined by the arrowhead pattern formed when the filaments are decorated with HMM, appears to be directed away from the sarcolemma. No evidence of polarity reversal was observed at the dense bands. Although function and significance is unknown, we assume the electron dense bands of the myofibril terminal segment of guppy muscle are not Z-lines, but rather, are structures unique to guppy muscle.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01323124
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