Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Muscle development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1986

Cerebral dysgeneses and their influence on fetal muscle development.

Abnormal suprasegmental influences of the brainstem and cerebellum on the developing motor unit during the histochemical stage of muscle development (20-28 weeks gestation) may alter the rate of maturation of striated muscle or may cause abnormal proportions and relative sizes of histochemical fibre types. Such aberrations without primary myopathic or denervative changes are commonly found in children with cerebral malformations, particularly associated with cerebellar hypoplasia. Upper motor neuron disease during embryonic life may explain histochemical alterations in some nonprogressive 'congenital myopathies' such as congenital muscle fibre-type disproportion, nemaline rod disease, and central core disease. Suprasegmental factors also may contribute to some aspects of the muscle pathology in the muscular dystrophies, especially the Fukuyama type of congenital muscular dystrophy regularly associated with cerebral dysgenesis. Fibre-type predominance or delayed histochemical differentiation thus may serve as a useful marker, in the muscle biopsy, of upper motor neuron disease. During the critical period of muscle development implicated, the corticospinal tract probably is of much less importance in muscle maturation than the multiple small bulbospinal pathways which also subserve motor control in nonmammalian vertebrates.

Brain↗
PubMed1984

Myosin subunit composition in human developing muscle.

Previous pyrophosphate-gel studies have reported the existence of embryonic neonatal myosin isoenzymes in human developing muscle. The present investigation was undertaken to characterize their subunit composition more precisely. Two immature muscle myosins are contrasted with adult myosin: neonatal myosin and foetal myosin. The neonatal form of myosin is weakly cross-reactive with rabbit slow myosin and contains only fast-type light chains (LC), LC1F and LC2F. The associated heavy chains consist of a single electrophoretic component that reacts exclusively with antibodies against human foetal myosin and has a mobility and peptide pattern distinct from that of adult fast and slow heavy chains. Foetal myosin is distinguished by the presence of low amounts of a heavy chain immunologically cross-reactive with the adult slow form and of two additional light-chain components: a LC2S light chain and a foetal-specific light chain (LCemb.). The foetal-specific light chain, as shown by one-dimensional-peptide-map analysis, is structurally unrelated to both LC1S and LC1F light chains of human adult myosin. We conclude from these results that the ontogenesis of human muscle myosin shares certain common features with that observed in other species, except for the persistence until birth of a foetal form of heavy chain (HCemb.).

Adult↗
PubMed1992

The proximal promoter of the aldolase A gene remains active during myogenesis in vitro and muscle development in vivo.

The gene for aldolase A in mouse has been shown to be regulated by alternative promoters with attendant alternative first exons. The distal promoter/exon M functions only in muscle while the proximal promoter/exon H is active in early muscle development and in most other tissues. We have analyzed the developmental expression of M and H promoters in mouse throughout myogenesis both in vitro and in vivo. In C2C12 cells RNase protection assays revealed the M promoter is induced within 24 hr of the onset of myogenic differentiation, and both M- and H-specific mRNAs accumulate over 5 days in culture. Nuclear run-on transcription and in situ hybridization with an exon-specific probe demonstrate that the H promoter remains transcriptionally active even in differentiated myotubes. The in vitro results were then compared to similar RNase protection studies of M and H expression during muscle development in vivo. These data show a marked similarity between promoter activation and steady-state transcript accumulation in vivo and in vitro, but within a limited developmental time frame (E15 to 1 week postnatal). In situ hybridizations suggest that simultaneous transcription from both promoters may also occur early in muscle development. Furthermore, the M promoter shows no fiber-type restriction until 1 to 3 weeks postnatally, coincident with muscle maturation, while the H promoter remains transcriptionally active at all stages of development and in all fiber types.

Animals↗
PubMed1984

Extracellular matrix organization in developing muscle: correlation with acetylcholine receptor aggregates.

Monoclonal antibodies recognizing laminin, heparan sulfate proteoglycan, fibronectin, and two apparently novel connective tissue components have been used to examine the organization of extracellular matrix of skeletal muscle in vivo and in vitro. Four of the five monoclonal antibodies are described for the first time here. Immunocytochemical experiments with frozen-sectioned muscle demonstrated that both the heparan sulfate proteoglycan and laminin exhibited staining patterns identical to that expected for components of the basal lamina. In contrast, the remaining matrix constituents were detected in all regions of muscle connective tissue: the endomysium, perimysium, and epimysium. Embryonic muscle cells developing in culture elaborated an extracellular matrix, each antigen exhibiting a unique distribution. Of particular interest was the organization of extracellular matrix on myotubes: the build-up of matrix components was most apparent in plaques overlying clusters of an integral membrane protein, the acetylcholine receptor (AChR). The heparan sulfate proteoglycan was concentrated at virtually all AChR clusters and showed a remarkable level of congruence with receptor organization; laminin was detected at 70-95% of AChR clusters but often was not completely co-distributed with AChR within the cluster; fibronectin and the two other extracellular matrix antigens occurred at approximately 20, 8, and 2% of the AChR clusters, respectively, and showed little or no congruence with AChR. From observations on the distribution of extracellular matrix components in tissue cultured fibroblasts and myogenic cells, several ideas about the organization of extracellular matrix are suggested. (a) Congruence between AChR clusters and heparan sulfate proteoglycan suggests the existence of some linkage between the two molecules, possibly important for regulation of AChR distribution within the muscle membrane. (b) The qualitatively different patterns of extracellular matrix organization over myotubes and fibroblasts suggest that each of these cell types uses somewhat different means to regulate the assembly of extracellular matrix components within its domain. (c) The limited co-distribution of different components within the extracellular matrix in vitro and the selective immune precipitation of each antigen from conditioned medium suggest that each extracellular matrix component is secreted in a form that is not complexed with other matrix constituents.

Animals↗
PubMed1992

Edgeworth's legacy of cranial muscle development with an analysis of muscles in the ventral gill arch region of batoid fishes (Chondrichthyes: Batoidea).

A series of studies by Edgeworth demonstrated that cranial muscles of gnathostome fishes are embryologically of somitic origin, originating from the mandibular, hyoid, branchial, epibranchial, and hypobranchial muscle plates. Recent experimental studies using quail-chick chimeras support Edgeworth's view on the developmental origin of cranial muscles. One of his findings, the existence of the premyogenic condensation constrictor dorsalis in teleost fishes, has also been confirmed by molecular developmental studies. Therefore, developmental mechanisms for patterning of cranial muscles, as described and implicated by Edgeworth, may serve as structural entities or regulatory phenomena responsible for developmental and evolutionary changes. With Edgeworth's and other studies as background, muscles in the ventral gill arch region of batoid fishes are analyzed and compared with those of other gnathostome fishes. The spiracularis is regarded as homologous at least within batoid fishes, but its status within elasmobranchs remains unclear; developmental modifications of the spiracularis proper are evident in some batoid fishes and in several shark groups. The peculiar ventral extension of the spiracularis in electric rays and some stingrays may represent convergence, probably facilitating ventilation and/or feeding in both groups. The evolutionary origin of the "internus" and "externus" remains uncertain, despite the fact that a variety of forms of the constrictor superficiales ventrales in batoid fishes indicates an actual medio-ventral extension of the "externus." The intermandibularis is probably present only in electric rays. The "X" muscle occurs only in electric rays and is considered to be Edgeworth's intermandibularis profundus. Its association with the adductor mandibular complex in narkinidid and narcinidid electric rays may relate to its functional role in lower jaw movement. Contrary to common belief, in most batoid fishes as well as some sharks, muscles that originate from the branchial muscle plate and extend medially in the ventral gill arches do exist: the medial extension of the interbranchiales in most batoid fishes and some sharks and the "Y" muscle in the pelagic stingrays Myliobatos and Rhinoptera. The latter is another example of the medial extension of the "internus." Whether the interbranchiales and "Y" muscle are homologous within elasmobranchs and whether homologous with the obliques ventrales and/or transversi ventrales of osteichthyan fishes await further research. Four hypobranchial muscles are recognized in batoid fishes: the coracomandibularis, coracohyoideus, coracoarcualis, and coracohyomandibularis. The coracohyoideus is discrete from the coracoarcualis; its complete structural separation from the latter occurs in several groups of batoid fishes.(ABSTRACT TRUNCATED AT 400 WORDS)

Anatomy, Comparative↗
PubMedDate not supplied

Maternal ethanol consumption: effect on skeletal muscle development in guinea pig offspring.

The effect of ethanol on developing skeletal muscle was analyzed by examining the gastrocnemius muscle from newborn guinea pigs, exposed to ethanol during the second half of gestation. Electron microscopy revealed vacuolated sarcoplasmic reticula, enlarged lipid droplets, decreased glycogen and mitochondrial abnormalities in the skeletal muscle samples from the ethanol-exposed newborn guinea pigs. None of these abnormalities were seen in the newborn controls who were born to dams which consumed the same amount of calories as the ethanol-treated dams. The ethanol-associated abnormalities, seen in this study, are similar to those seen in ultrastructural examination of skeletal muscle from chronic alcoholics.

Animals↗
PubMed1991

Neonatal and adult myosin heavy chains form homodimers during avian skeletal muscle development.

Myosin isoforms contribute to the heterogeneity and adaptability of skeletal muscle fibers. Besides the well-characterized slow and fast muscle myosins, there are those isoforms that appear transiently during the course of muscle development. At a stage of development when two different myosins are coexpressed, the possibility arises for the existence of heterodimers, molecules containing two different heavy chains, or homodimers, molecules with two identical heavy chains. The question of whether neonatal and adult myosin isoforms can associate to form a stable heterodimer was addressed by using stage-specific monoclonal antibodies in conjunction with immunological and electron microscopic techniques. We find that independent of the ratio of adult to neonatal myosin, depending on the age of the animal, the myosin heavy chains form predominantly homodimeric molecules. The small amount of hybrid species present suggests that either the rod portion of the two heavy chain isoforms differs too much in sequence to form a stable alpha-helical coiled coil, or that the biosynthesis of the heavy chains precludes the formation of heterodimeric molecules.

Animals↗
PubMed1992

Genetic approaches to understanding muscle development.

The analysis of both naturally occurring and experimentally induced mutants has greatly advanced our understanding of muscle development. Molecular biological techniques have led to the isolation of genes associated with inherited human diseases that affect muscle tissues. Analysis of the encoded proteins in conjunction with the mutant phenotypes can provide powerful insights into the function of the protein in normal muscle development. Systematic searches for muscle mutations have been made in experimental systems, most notably the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans. In addition, known muscle protein genes from other organisms have been used to isolate homologs from genetically manipulatable organisms, allowing mutant analysis and the study of protein function in vivo. Mutations in transcription factor genes that affect mesoderm development have been isolated and genetic lesions affecting myofibril assembly have been identified. Genetic experiments inducing mutations and rescuing them by transgenic methods have uncovered functions of myofibrillar protein isoforms. Some isoforms perform muscle-specific functions, whereas others appear to be replaceable by alternative isoforms. Mutant analysis has also uncovered a relationship between proteins at the cell membrane and the assembly and alignment of the myofibrillar apparatus. We discuss examples of each of these genetic approaches as well as the developmental and evolutionary implications of the results.

Animals↗
PubMed2026

Effects of rumen fluid transplantation on longissimus dorsi muscle development in Xizang sheep: An association analysis based on transcriptomic and serum metabolomic profiles.

This study aimed to investigate the effects of rumen fluid transplantation (RFT) on the growth and development of the longissimus dorsi muscle in female Xizang sheep. After RFT, muscle lightness differed significantly between the two groups, with the LDC group showing significantly higher lightness than the LDT group. In contrast, no significant differences were observed between groups in other muscle phenotypic traits, including drip loss, pH, cooking loss, shear force, redness, and yellowness. Antioxidant-related indices (SOD, GSH-PX, MDA, CAT, and T-AOC) also showed no significant differences between groups. Histological analysis revealed that muscle fiber length, width, and density were significantly greater in the experimental group than in the control group. Transcriptomic analysis identified 515 differentially expressed genes (DEGs), of which 419 were downregulated. KEGG analysis indicated that genes involved in muscle development-related pathways, such as cell adhesion and the PI3K-Akt signaling pathway, were predominantly downregulated. Key serum metabolites (L-kynurenine, IPA, allantoin, and propionylcarnitine) showed highly significant positive correlations with muscle fiber growth indices. In contrast, metabolites such as l-carnitine, acetylcarnitine, and citrulline were negatively correlated with muscle fiber growth, but positively correlated with the expression of muscle structure-related genes (COL11A1 and EFNA5) and with meat lightness. Overall, this study provides new insights into the potential molecular basis by which RFT influences muscle growth and development. However, the mechanisms by which RFT affects muscle development and meat quality-related traits remain unclear and warrant further investigation.

Animals↗
PubMed1982

Scanning electron microscopy of prenatal muscle development in the mouse.

Scanning electron microscopy was used to study prenatal muscle development in mouse fetuses ranging from 12 days to 18 days gestation. Some transmission electron micrographs were also used for comparison. At 12 days no myofibres were evident although at 13 days long fibres surrounded by many mononucleated cells could be seen. At 14 days bundles of primary myofibres were observed with new myofibres forming in crevices between adjacent fibres. At 16 days the primary myofibres had separated but smaller secondary myofibres could be seen forming along their surfaces. The myofibres were very compact at 18 days and often appeared fused but this was due to the basal lamina ensheathing clusters of primary myofibres with their secondaries. The scanning electron micrographs appeared to illustrate the theories of muscle development which have arisen out of the various studies employing sectioning techniques.

Animals↗
PubMed1976

The effect of testosterone on skeletal muscle development and protein synthesis in rabbits.

The effect of testosterone administration on muscle development and protein synthesis was studied with intact male rabbits. Rabbits were randomized into three experimental groups; day 0 control (G-1), day 15 control (G-2) and day 15 testosterone (G-3). Testosterone (delta4-Androsten-17beta-ol-3-one in silastic tubing) was surgically implanted into the G-3 rabbits. On day (G-1) and day 15 (G-2 and 3) of the experiment all rabbits were injected IP with 50 mu Ci-3H-leucine. Rabbits were sacrificed at intervals after the 3H-leucine injection. Right and left semitendinosus muscles, pituitary and adrenal glands, testicles and blood samples were obtained for analysis. Testosterone improved (P less than .01) gain and feed efficiency, depressed testicle weight (P less than .01), increased serum testosterone and insulin (P less than 0.01) but did not affect adrenal and pituitary weights. Muscle moisture, fat and total protein, myofibrillar, sarcoplasmic and stromal protein fractions and RNA and DNA content were not significantly affected by testosterone although G-3 semitendinosus muscle had the highest total and myofibrillar protein, RNA, and DNA content. The testosterone treated rabbits (G-3) had higher (P less than 0.05) 3H-leucine incorporation into myofibrillar protein and lower 3H-leucine incorporation into sarcoplasmic protein than the day 0 and day 15 controls.

Adrenal Glands↗
PubMed1984

Effect of maternal alcohol consumption on pre- and post-natal muscle development of mice.

The effect of maternal alcohol consumption during pregnancy on muscle development of the offspring was investigated in 28 mice (14 males, 14 females) at 12 weeks of age. Both the control and alcohol-fed groups received food ad-libitum throughout the period of study. The control group received water ad-libitum also throughout the period of study. The alcohol-fed group, on the other hand, received only water up to six weeks of age. Subsequently, between 6 and 8 weeks of age they received 10% ethanol (v/v) in water and 20% ethanol (v/v) from 8 to 11 weeks age. Both groups were bred at 11 weeks of age. Following diagnosis of pregnancy, the alcohol-fed group received 30% ethanol (v/v) till delivery. The off-spring of both groups were fed water and food ad-libitum throughout the period of study. Each of the off-spring was killed at 12 weeks of age. Body weight, as well as weights of soleus, biceps brachii, long digital extensor and cranial tibial muscles were significantly smaller in off-spring of the alcohol-fed group indicating that maternal consumption of alcohol during pregnancy retards growth, as well as "catch-up growth" in both body weights and muscle mass. The smaller muscle mass, as observed from analyses of soleus muscle, resulted from retardation of muscle growth pre-natally by suppression of normal hyperplasia of muscle fibres during myogenesis and postnatally by suppression of normal hypertrophy of muscle fibres.

Animals↗
PubMed1985

Monoclonal antibodies to desmin: evidence for stage-dependent intermediate filament immunoreactivity during cardiac and skeletal muscle development.

Monoclonal antibodies reactive with desmin (D3 and D76) have been generated and their specificities validated by immunoblots, RIAs, and immunocytochemistry. No cross-reaction with other IFPs has been observed. The McAbs recognized different epitopes but both reside in the amino-terminal rod domain of desmin. Whereas McAb D3 produces a staining pattern characteristic of desmin throughout the development of cardiac and skeletal muscles, McAb D76 was selectively unreactive with certain regions of early (three days in ovo) embryonic cardiac anlage, with cultured cardiac myocytes derived from 7-day-old embryos, and with skeletal myotubes in early stages of myogenesis in vitro. Positive reactivity of D76 was seen at stages of myofibrillogenesis when the sarcomeres assume lateral alignment. Evidence was presented that differential reactivity of D76 did not result from the biosynthesis of a new desmin isoform or the post-translational modification of an existing protein. We suggest that the appearance of D76 immunoreactivity during striated muscle development represents an unmasking of the epitope by some IF-associated protein. Since this transition during skeletal muscle differentiation occurs during lateral alignment of the myofibrils, this antibody may serve as a useful probe for exploring this reorganization of the contractile apparatus during myogenesis and muscle regeneration.

Animals↗
PubMed1992

Differential regulation of the atrial isoforms of the myosin light chains during striated muscle development.

We have isolated a cDNA that encodes the human regulatory myosin light chain isoform predominant in adult atrial muscle. The cDNA contains an open reading frame of 175 amino acids and encodes a hydrophilic protein of a largely helical structure with two potential phosphorylation sites. The protein is different from any other regulatory myosin light chain so far described and is the product of a previously uncharacterized single copy gene. An isoform-specific probe was used to analyze the expression of this isoform in adult muscle and in cardiac and skeletal muscle development in vivo and in vitro. Parallel analysis of the corresponding human alkali myosin light chain (predominant in adult atrium) showed that both isoforms are expressed in early heart development, in both atrium and ventricle. Although the atrial alkali light chain is expressed throughout embryonic striated muscle development, the regulatory myosin light chain was not detected in skeletal myogenesis in vivo or in vitro. Thus the atrial isoforms are not universally or exclusively "paired" and can be independently regulated. We propose that the manner in which these particular isoforms fulfill the functional requirements of the muscle at different developmental times may have direct impact on their regulation.

Adult↗
PubMed1989

Genetic analysis of muscle development in Drosophila melanogaster.

The different thoracic muscles of Drosophila are affected specifically in the mutants: stripe (sr), erect wing (ewg), vertical wings (vtw), and nonjumper (nj). We have tested the extent of this specificity by means of a genetic analysis of these loci, multiple mutant combinations, and gene dosage experiments. A quantitative, rather than a qualitative, specificity is found in the mutant phenotypes. All muscles are altered by mutations in any given gene, but the severity of these alterations is muscle specific. The locus stripe seems to have a polar organization where different allelic combinations show quantitative specificity in the muscle affected. In addition to the muscle phenotypes, neural alterations are detected in these mutants. The synergism found between ewg, vtw and ewg, sr as well as the dosage effect of the distal end of the X chromosome upon the expression of ewg and sr suggests the existence of functional relationships among the loci analyzed.

Alleles↗
PubMed1988

Myosin ATPase activity during avian cardiac and skeletal muscle development.

The myosin ATPase activity and myosin light chain composition in developing chick heart and skeletal muscles were studied and compared. Embryonic myosin was purified and characterized from day 7 to day 19 of embryogenesis. Embryonic cardiac myosin generally showed the same Ca2+-activated myosin ATPase activity level as the adult value. In comparison, pooled pectoralis and hindlimb skeletal muscles from day 10 through day 19 showed myosin ATPase activities that were all significantly less than the adult counterpart. The myosin light chain pattern of embryonic cardiac myosin remained relatively constant like the myosin ATPase activity, whereas developmental changes were observed in skeletal myosin light chains.

Animals↗