Satellite cell activation in the stretch-enlarged anterior latissimus dorsi muscle of the adult quail

1991 ◽  
Vol 260 (2) ◽  
pp. C206-C212 ◽  
Author(s):  
P. K. Winchester ◽  
M. E. Davis ◽  
S. E. Alway ◽  
W. J. Gonyea
Keyword(s):  
Satellite Cell ◽  
Satellite Cells ◽  
Latissimus Dorsi ◽  
Tritiated Thymidine ◽  
Cell Activity ◽  
Muscle Length ◽  
Latissimus Dorsi Muscle ◽  
Cell Labeling ◽  
Dorsi Muscle ◽  
Anterior Latissimus Dorsi

Satellite cell activity was examined in the stretch-enlarge anterior latissimus dorsi muscle (ALD) of the adult quail. Thirty-seven birds had a weight equal to 10% of their body mass attached to one wing while the contralateral wing served as an intra-animal control. At various time intervals after application of the wing weight (from 1 to 30 days), the birds were injected with tritiated thymidine and killed 1 h later. Stretched muscle length was greater by day 1 and mass by day 3 when compared with the contralateral muscle. Satellite cells actively synthesizing DNA were quantitated in fiber segments of the control and stretched ALD. A minimum of 1,500 muscle nuclei (satellite cell nuclei and myonuclei) were counted in each muscle. Labeling in stretched muscle was expressed by the percent labeled nuclei per total nuclei counted. Satellite cell labeling was initiated by day 1, peaked between days 3 and 7, and was not statistically different from control values at day 30. These results demonstrate that satellite cells are induced to enter the cell cycle in the stretch-enlarged ALD muscle from the adult quail, and the peak of proliferative activity is within the first week of stretch.

scholarly journals Retention of Pax3 Expression in Satellite Cells of Muscle Spindles

2009 ◽  
Vol 58 (4) ◽  
pp. 317-327 ◽  
Author(s):  
Lisa J. Kirkpatrick ◽  
Zipora Yablonka-Reuveni ◽  
Benjamin W.C. Rosser
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Latissimus Dorsi ◽  
Muscle Spindles ◽  
Latissimus Dorsi Muscle ◽  
Intrafusal Fibers ◽  
Dorsi Muscle ◽  
Avian Muscle ◽  
Anterior Latissimus Dorsi ◽  
Immunohistochemical Techniques

Intrafusal fibers within muscle spindles retain features characteristic of immaturity, unlike the larger and more numerous extrafusal fibers constituting the bulk of skeletal muscle. Satellite cells (SCs), myogenic progenitors, are detected on the surfaces of both intrafusal and extrafusal fibers, but little is known of spindle SCs. We have recently demonstrated that, like their extrafusal counterparts, SCs in muscle spindles of posthatch chickens express paired box transcription factor 7 (Pax7) protein. During vertebrate embryogenesis, myogenic progenitors express both Pax7 and Pax3 proteins. In postnatal mice, Pax3 appears in rare SC subsets, whereas Pax7 is expressed by all SCs within extrafusal fibers. Here we test the hypothesis that Pax3 protein maintains localized expression within SCs of muscle spindles. Immunohistochemical techniques were used to identify SCs by their Pax7 expression within anterior latissimus dorsi muscle excised from posthatch chickens of various ages. A greater percentage of SCs express Pax3 within intrafusal than extrafusal fibers at each age, and the proportion of SCs expressing Pax3 declines with aging. This is the first study to localize Pax3 expression in posthatch avian muscle and within SCs of muscle spindles. We suggest that Pax3-positive SCs are involved in fiber maintenance.

scholarly journals Electrophoretic analysis of multiple forms of myosin in fast-twitch and slow-twitch muscles of the chick

1976 ◽  
Vol 157 (1) ◽  
pp. 87-95 ◽  
Author(s):  
J F Y Hoh ◽  
P A McGrath ◽  
R I White
Keyword(s):  
Latissimus Dorsi ◽  
Electrophoretic Analysis ◽  
Latissimus Dorsi Muscle ◽  
Buffer System ◽  
Dorsi Muscle ◽  
Atpase Reaction ◽  
Anterior Latissimus Dorsi ◽  
Slow Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

1. A method is described for the electrophoretic analysis of intact myosin in polyacrylamide gel in a buffer system containing 0.02 M-pyrophosphate and 10% (v/v) glycerol, pH 8.8. 2. In this system chicken skeletal-muscle myosins reveal five distinct electrophoretic components, three components from the fast-twitch posterior latissimus dorsi muscle and two slower-migrating components from the slow-twitch anterior latissimus dorsi muscle. 3. The Ca2+-activated ATPase (adenosine triphosphatase) activity of myosin components was measured by densitometric scanning of the gel for the Ca3(PO4)2 precipitate formed during the ATPase reaction and subsequently for stained protein. Each component from the same muscle appears to have identical ATPase activity, but components from the fast-twitch muscle had an activity 2.2 times higher than those from the slow-twitch muscle. 4. On re-electrophoresis in the same buffer system, individual fractions of fast-twitch myosin did not reproduce the three-band pattern of the original myosin, but migrated at rates consistent with their original mobility. 5. Analysis of the mobility of the three fast-twitch myosin components in gels of different concentrations suggests that they are not stable oligomers of each other. 6. It is suggested that these components of fast-twitch myosin and slow-twitch myosin are isoenzymes of myosin.

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