scholarly journals THE HISTOGENESIS OF RAT INTERCOSTAL MUSCLE

1969 ◽  
Vol 42 (1) ◽  
pp. 135-153 ◽  
Author(s):  
A. M. Kelly ◽  
S. I. Zacks
Keyword(s):  
Muscle Cells ◽  
Small Cells ◽  
Intercostal Muscle ◽  
Undifferentiated Cells ◽  
Single Well ◽  
Muscle Groups ◽  
Well Differentiated ◽  
Mode Of Development ◽  
Developing System ◽  
Developing Muscle

Intercostal muscle from fetal and newborn rats was examined with the electron microscope. At 16 days' gestation, the developing muscle was composed of primary generations of myotubes, many of which were clustered together in groups. Within these groups, the membranes of neighboring myotubes were interconnected by specialized junctions, including tight junctions. Morphologically undifferentiated cells surrounded the muscle groups, frequently extended pseudopodia along the interspace between adjacent myotubes, and appeared to separate neighboring myotubes from one another. At 18 and 20 days' gestation, the muscle was also composed of groups of cells but the structure of the groups differed from that of the groups observed at 16 days. Single, well differentiated myotubes containing much central glycogen and peripheral myofibrils dominated each group. These large cells were interpreted as primary myotubes. Small, less differentiated muscle cells and undifferentiated cells clustered around their walls. Each cluster was ensheated by a basal lamina. The small cells were interpreted as primordia of new generations of muscle cells which differentiated by appositional growth along the walls of the large primary myotubes. All generations of rat intercostal muscle cells matured to myofibers between 20 days' gestation and birth. Coincidentally, large and small myofibers diverged from each other, leading to disintegration of the groups of muscle cells. Undifferentiated cells frequently occurred in the interspaces between neighboring muscle cells at the time of separation. Myofibers arising at different stages of muscle histogenesis intermingled in a checkerboard fashion as a result of this asynchronous mode of development. The possibility of fusion between neighboring muscle cells in this developing system is discussed.

scholarly journals SARCOPLASMIC RETICULUM AND T TUBULES IN DIFFERENTIATING RAT SKELETAL MUSCLE

1971 ◽  
Vol 49 (2) ◽  
pp. 335-344 ◽  
Author(s):  
A. M. Kelly
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Electron Microscope Study ◽  
Muscle Cells ◽  
Neonatal Rat ◽  
Intercostal Muscle ◽  
Rat Skeletal Muscle ◽  
Undifferentiated Cells ◽  
T Tubules ◽  
Further Development

An electron microscope study has been made of the distribution of membrane couplings between the sarcoplasmic reticulum (SR) and either the plasmalemma or the T tubules in fetal and neonatal rat intercostal muscle. Within primitive muscle cells at 12 days of gestation, the SR forms both simple and specialized membrane junctions with the plasmalemma; caveolae are very few, and T tubules are not detected. Undifferentiated cells neighbor muscle cells. Occasionally these cells contain subsurface couplings between the endoplasmic reticulum and plasmalemmae. Possible relationships between these couplings and the peripheral couplings of muscle cells are discussed. By 15–18 days of gestation, caveolae and beaded T tubules, comparable to those of cultured muscle, develop; T tubules lie along-side myofibrils and are rarely transverse. SR couples both to T tubules and to plasmalemmae during this period. T tubules with lineal profiles appear after further development and their orientation transverse to A–I junctions becomes increasingly evident. Membrane couplings between SR and T tubules also increase in number, whereas the incidence of peripheral coupling declines rapidly Evidence suggests that peripheral couplings are swept into myotubes as caveolae proliferate and T tubules form. SR thus appears to initially couple with the plasmalemma and then to await T tubular growth. This contrasts with the developmental pattern described in cultured chick muscle in which peripheral couplings are not reported and T tubules with diads and triads occur at very primitive stages of muscle differentiation.

Identification of upstream and intragenic regulatory elements that confer cell-type-restricted and differentiation-specific expression on the muscle creatine kinase gene

1988 ◽  
Vol 8 (7) ◽  
pp. 2896-2909 ◽  
Author(s):  
E A Sternberg ◽  
G Spizz ◽  
W M Perry ◽  
D Vizard ◽  
T Weil ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Regulatory Element ◽  
Simian Virus 40 ◽  
Muscle Cells ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Simian Virus ◽  
Cell Type ◽  
Specific Expression ◽  
Developing Muscle

Terminal differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific gene products, which includes the muscle isoenzyme of creatine kinase (MCK). To begin to define the sequences and signals involved in MCK regulation in developing muscle cells, the mouse MCK gene has been isolated. Sequence analysis of 4,147 bases of DNA surrounding the transcription initiation site revealed several interesting structural features, some of which are common to other muscle-specific genes and to cellular and viral enhancers. To test for sequences required for regulated expression, a region upstream of the MCK gene from -4800 to +1 base pairs, relative to the transcription initiation site, was linked to the coding sequences of the bacterial chloramphenicol acetyltransferase (CAT) gene. Introduction of this MCK-CAT fusion gene into C2 muscle cells resulted in high-level expression of CAT activity in differentiated myotubes and no detectable expression in proliferating undifferentiated myoblasts or in nonmyogenic cell lines. Deletion mutagenesis of sequences between -4800 and the transcription start site showed that the region between -1351 and -1050 was sufficient to confer cell type-specific and developmentally regulated expression on the MCK promoter. This upstream regulatory element functioned independently of position, orientation, or distance from the promoter and therefore exhibited the properties of a classical enhancer. This upstream enhancer also was able to confer muscle-specific regulation on the simian virus 40 promoter, although it exhibited a 3- to 5-fold preference for its own promoter. In contrast to the cell type- and differentiation-specific expression of the upstream enhancer, the MCK promoter was able to function in myoblasts and myotubes and in nonmyogenic cell lines when combined with the simian virus 40 enhancer. An additional positive regulatory element was identified within the first intron of the MCK gene. Like the upstream enhancer, this intragenic element functioned independently of position, orientation, and distance with respect to the MCK promoter and was active in differentiated myotubes but not in myoblasts. These results demonstrate that expression of the MCK gene in developing muscle cells is controlled by complex interactions among multiple upstream and intragenic regulatory elements that are functional only in the appropriate cellular context.

scholarly journals Biosynthesis of titin in cultured skeletal muscle cells.

1989 ◽  
Vol 109 (5) ◽  
pp. 2189-2195 ◽  
Author(s):  
W B Isaacs ◽  
I S Kim ◽  
A Struve ◽  
A B Fulton
Keyword(s):  
Skeletal Muscle ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Significant Progress ◽  
Large Protein ◽  
Time Period ◽  
And Function ◽  
Triton X ◽  
Developing Muscle ◽  
Synchronized Cultures

Although significant progress has been made regarding the structure and function of titin, little data exist on the biosynthesis of this large protein in developing muscle. Using pulse-labeling with [35S]methionine and immunoprecipitation with an anti-titin mAb, we have examined the biosynthesis of titin in synchronized cultures of skeletal muscle cells derived from day 12 chicken embryos. We find that: (a) titin synthesis increases greater than 4-fold during the first week in culture and during this same time period, synthesis of muscle-specific myosin heavy chain increases greater than 12-fold; (b) newly synthesized titin has a t1/2 of approximately 70 h; (c) titin is resistant to extraction with Triton X-100 both during and immediately after its synthesis. These observations suggest that newly synthesized titin molecules are stable proteins that rapidly associate with the cytoskeleton of developing myotubes.

scholarly journals DIFFERENTIATION OF THE SARCOPLASMIC RETICULUM AND T SYSTEM IN DEVELOPING CHICK SKELETAL MUSCLE IN VITRO

1967 ◽  
Vol 35 (2) ◽  
pp. 405-420 ◽  
Author(s):  
Elizabeth B. Ezerman ◽  
Harunori Ishikawa
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Osmium Tetroxide ◽  
Muscle Cells ◽  
Simultaneous Occurrence ◽  
Chick Embryos ◽  
Developing Muscle ◽  
T System

The electron microscope was used to investigate the first 10 days of differentiation of the SR and the T system in skeletal muscle cultured from the breast muscle of 11-day chick embryos. The T-system tubules could be clearly distinguished from the SR in developing muscle cells fixed with glutaraldehyde and osmium tetroxide. Ferritin diffusion confirmed this finding: the ferritin particles were found only in the tubules identified as T system. The proliferation of both membranous systems seemed to start almost simultaneously at the earliest myotube stage. Observations suggested that the new SR membranes developed from the rough-surfaced ER as tubular projections. The SR tubules connected with one another to form a network around the myofibril. The T-system tubules were formed by invagination of the sarcolemma. The early extension of the T system by branching and budding was seen only in subsarcolemmal regions. Subsequently the T-system tubules could be seen deep within the muscle cells. Immediately after invaginating, the T-system tubule formed, along its course, specialized connections with the SR or ER: triadic structures showing various degrees of differentiation. The simultaneous occurrence of myofibril formation and membrane proliferation is considered to be important in understanding the coordinated events resulting in the differentiated myotube.

Bovine distal pulmonary arterial media is composed of a uniform population of well-differentiated smooth muscle cells with low proliferative capabilities

2003 ◽  
Vol 285 (4) ◽  
pp. L819-L828 ◽  
Author(s):  
Leopold Stiebellehner ◽  
Maria G. Frid ◽  
John T. Reeves ◽  
Robert B. Low ◽  
Meena Gnanasekharan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Pulmonary Circulation ◽  
Main Pulmonary Artery ◽  
Muscle Cells ◽  
Hypoxic Exposure ◽  
Growth Responses ◽  
The Media ◽  
Well Differentiated ◽  
Uniform Population

The media of the normal bovine main pulmonary artery (MPA) is composed of phenotypically heterogeneous smooth muscle cells (SMC) with markedly different proliferative capabilities in response to serum, mitogens, and hypoxia. Little, however, is known of the SMC phenotype in distal pulmonary arteries (PA), particularly in arterioles, which regulate the pulmonary circulation. With a panel of muscle-specific antibodies against α-smooth muscle (SM)-actin, SM-myosin heavy chains (SM-MHC), SM-MHC-B isoform, desmin, and meta-vinculin, we demonstrate a progressive increase in phenotypic uniformity and level of differentiation of SMC along the proximal-to-distal axis of normal adult bovine pulmonary circulation so that the media of distal PA (1,500- to 100-μm diameter) is composed of a phenotypically uniform population of “well-differentiated” SMC. Similarly, when isolated and assessed in vitro, distal PA-SMC is composed of a single, uniform population of differentiated SMC that exhibited minimal growth responses to a variety of mitogens while their cell size increased substantially in response to serum. Their growth was inhibited by hypoxic exposure under all conditions tested. Distal PA-SMC also differed from MPA-SMC by exhibiting a distinct pattern of DNA synthesis in response to serum and mitogens. Thus, in contrast to the MPA, distal PA media is composed of an apparently uniform population of well-differentiated SMC that are proliferation resistant and have a substantial capacity to hypertrophy in response to growth-promoting stimuli. We thus speculate that distinct SMC phenotypes present in distal vs. proximal PA may confer different response mechanisms during remodeling in conditions such as hypertension.

scholarly journals A 295-kDA intermediate filament-associated protein in radial glia and developing muscle cells in vivo and in vitro

2000 ◽  
Vol 219 (4) ◽  
pp. 514-525 ◽  
Author(s):  
Grazyna Chanas-Sacr� ◽  
Marc Thiry ◽  
Sandrine Pirard ◽  
Bernard Rogister ◽  
Gustave Moonen ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Radial Glia ◽  
Muscle Cells ◽  
Developing Muscle

scholarly journals THE FINE STRUCTURE OF EMBRYONIC CHICK SKELETAL MUSCLE CELLS DIFFERENTIATED IN VITRO

1967 ◽  
Vol 35 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Y. Shimada ◽  
D. A. Fischman ◽  
A. A. Moscona
Keyword(s):  
Electron Microscopy ◽  
Skeletal Muscle ◽  
Fine Structure ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Developing Muscle

Dissociated myoblasts from 12-day chick embryos were cultured in monolayer, and the differentiation of skeletal muscle cells was studied by electron microscopy. The results have revealed a striking ultrastructural similarity between the in vivo and the in vitro developing muscle, particularly with respect to the myofibrils and sarcoplasmic reticulum. This study demonstrates that all the characteristic organelles of mature skeletal muscle can develop in vitro in the absence of nerves.

Chemical fat in the musculature of the sheep carcass

1973 ◽  
Vol 80 (2) ◽  
pp. 219-224 ◽  
Author(s):  
W. J. Pryor ◽  
G. H. Warren
Keyword(s):  
Hind Limb ◽  
Dry Matter ◽  
Mean Value ◽  
Fat Content ◽  
Muscle Group ◽  
Intercostal Muscle ◽  
Merino Sheep ◽  
Acid Lactone ◽  
The Mean ◽  
Muscle Groups

SummaryForty merino sheep of mixed ages including lambs, ewes, wethers and rams were slaughtered and dissected. The chemical fat content often muscle groups in each sheep was measured directly and the mean value for the musculature of the whole carcass calculated.A characteristic pattern of chemical fat deposition was shown with the intercostal muscle group and the abdominal group being consistently highest in fat content, the shin and hind-limb muscles lowest and other intermediate. The pattern of growth of intramviscular fat was consistent with differences in activity of the muscle groups in the maintenance of posture. It was postulated that variations in fat content in muscle groups are affected by differences in blood flow.A highly significant relationship was established between dry matter and chemical fat content for each of the muscle groups. The regression was characteristic for each muscle group, and differed for most groups.Regressions between individual muscle group fat and that of total musculature fat revealed that no group was consistently the best predictor of the total carcass musculature fat though there was considerable difference between the groups. It was concluded there is no group which could be used for prediction purposes commercially.In a group of 14 other ewes subjected to weight loss up to 30%, and half of which were implanted with resorcylic acid lactone, no discernible effects on muscle group fat content were revealed.

scholarly journals Reverse-engineering forces responsible for dynamic clustering and spreading of multiple nuclei in developing muscle cells

2020 ◽  
Vol 31 (16) ◽  
pp. 1802-1814
Author(s):  
Angelika Manhart ◽  
Mafalda Azevedo ◽  
Mary Baylies ◽  
Alex Mogilner
Keyword(s):  
Reverse Engineering ◽  
Muscle Development ◽  
Muscle Cells ◽  
Cell Length ◽  
Dynamic Clustering ◽  
Nuclear Dynamics ◽  
Computational Screening ◽  
Developing Muscle

During Drosophila muscle development, multiple nuclei transition from being clustered together, to splitting into two smaller clusters, to spreading along the cell length. Computational screening reveals that initial short-ranged internuclear attraction and final long-ranged repulsion, overlapping in time, are responsible for the nuclear dynamics.

scholarly journals Distinct Expression and Clinical Significance of Zinc Finger AN-1-Type Containing 4 in Oral Squamous Cell Carcinomas

2018 ◽  
Vol 7 (12) ◽  
pp. 534
Author(s):  
Julián Suárez-Canto ◽  
Faustino Suárez-Sánchez ◽  
Francisco Domínguez-Iglesias ◽  
Gonzalo Hernández-Vallejo ◽  
Juana García-Pedrero ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Squamous Cell ◽  
Expression Patterns ◽  
Tumor Location ◽  
Clinical Implementation ◽  
Normal Epithelium ◽  
Differentiated Cells ◽  
Undifferentiated Cells ◽  
Clinicopathologic Parameters ◽  
Well Differentiated

Zinc finger AN1-type containing 4 (ZFAND4) has emerged as a promising prognostic marker and predictor of metastasis for patients with oral squamous cell carcinoma (OSCC). However, further validation is fundamental before clinical implementation. Hence, this study evaluated the expression pattern of ZFAND4 protein expression by immunohistochemistry using an independent cohort of 125 patients with OSCC, and correlations with the clinicopathologic parameters and disease outcome. Remarkably, ZFAND4 expression, while negligible in normal epithelium, exhibited two distinct expression patterns in tumors that did not overlap. A gross granular staining was characteristic of the undifferentiated cells at the invasive front of tumors, whereas the most differentiated cells located at the center of the tumor nests showed diffuse non-granular staining. ZFAND4 staining was higher in undifferentiated than in differentiated areas of tumors. High ZFAND4 expression in differentiated cells was significantly associated to well-differentiated (p = 0.04) and non-recurrent tumors (p = 0.04), whereas ZFAND4 expression in undifferentiated cells correlated with tumor location (p = 0.005). No correlations between the ZFAND4 expression and patient survival were found. These data question the clinical relevance of ZFAND4 expression as a prognostic biomarker in OSCC, and also reveal distinct ZFAND4 expression patterns depending on the differentiation areas of tumors that should be evaluated separately.

Sign in / Sign up

Export Citation Format

Share Document