scholarly journals Fine-mapping of genes determining extrafusal fiber properties in murine soleus muscle

2017 ◽  
Vol 49 (3) ◽  
pp. 141-150 ◽  
Author(s):  
A. M. Carroll ◽  
R. Cheng ◽  
E. S. R. Collie-Duguid ◽  
C. Meharg ◽  
M. E. Scholz ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Muscle Fiber ◽  
Soleus Muscle ◽  
Genomic Sequence ◽  
Sequence Data ◽  
Mouse Strains ◽  
Sequence Information ◽  
Type I ◽  
Fiber Types ◽  
Genome Wide

Muscle fiber cross-sectional area (CSA) and proportion of different fiber types are important determinants of muscle function and overall metabolism. Genetic variation plays a substantial role in phenotypic variation of these traits; however, the underlying genes remain poorly understood. This study aimed to map quantitative trait loci (QTL) affecting differences in soleus muscle fiber traits between the LG/J and SM/J mouse strains. Fiber number, CSA, and proportion of oxidative type I fibers were assessed in the soleus of 334 genotyped female and male mice of the F34generation of advanced intercross lines (AIL) derived from the LG/J and SM/J strains. To increase the QTL detection power, these data were combined with 94 soleus samples from the F2intercross of the same strains. Transcriptome of the soleus muscle of LG/J and SM/J females was analyzed by microarray. Genome-wide association analysis mapped four QTL (genome-wide P < 0.05) affecting the properties of muscle fibers to chromosome 2, 3, 4, and 11. A 1.5-LOD QTL support interval ranged between 2.36 and 4.67 Mb. On the basis of the genomic sequence information and functional and transcriptome data, we identified candidate genes for each of these QTL. The combination of analyses in F2and F34AIL populations with transcriptome and genomic sequence data in the parental strains is an effective strategy for refining QTL and nomination of the candidate genes.

Gene Polymorphisms and Fiber-Type Composition of Human Skeletal Muscle

2012 ◽  
Vol 22 (4) ◽  
pp. 292-303 ◽  
Author(s):  
Ildus I. Ahmetov ◽  
Olga L. Vinogradova ◽  
Alun G. Williams
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Human Skeletal Muscle ◽  
Fiber Type ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Type I Fibers

The ability to perform aerobic or anaerobic exercise varies widely among individuals, partially depending on their muscle-fiber composition. Variability in the proportion of skeletal-muscle fiber types may also explain marked differences in aspects of certain chronic disease states including obesity, insulin resistance, and hypertension. In untrained individuals, the proportion of slow-twitch (Type I) fibers in the vastus lateralis muscle is typically around 50% (range 5–90%), and it is unusual for them to undergo conversion to fast-twitch fibers. It has been suggested that the genetic component for the observed variability in the proportion of Type I fibers in human muscles is on the order of 40–50%, indicating that muscle fiber-type composition is determined by both genotype and environment. This article briefly reviews current progress in the understanding of genetic determinism of fiber-type proportion in human skeletal muscle. Several polymorphisms of genes involved in the calcineurin–NFAT pathway, mitochondrial biogenesis, glucose and lipid metabolism, cytoskeletal function, hypoxia and angiogenesis, and circulatory homeostasis have been associated with fiber-type composition. As muscle is a major contributor to metabolism and physical strength and can readily adapt, it is not surprising that many of these gene variants have been associated with physical performance and athlete status, as well as metabolic and cardiovascular diseases. Genetic variants associated with fiber-type proportions have important implications for our understanding of muscle function in both health and disease.

Carnitine metabolism in human muscle fiber types during submaximal dynamic exercise

1996 ◽  
Vol 80 (3) ◽  
pp. 1061-1064 ◽  
Author(s):  
D. Constantin-Teodosiu ◽  
S. Howell ◽  
P. L. Greenhaff
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Group Formation ◽  
Free Carnitine ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Carnitine Metabolism ◽  
Type I Fibers

The effect of prolonged exhaustive exercise on free carnitine and acetylcarnitine concentrations in mixed-fiber skeletal muscle and in type I and II muscle fibers was investigated in humans. Needle biopsy samples were obtained from the vastus lateralis of six subjects immediately after exhaustive one-legged cycling at approximately 75% of maximal O2 uptake from both the exercised and nonexercised (control) legs. In the resting (control) leg, there was no difference in the free carnitine concentration between type I and II fibers (20.36 +/- 1.25 and 20.51 +/- 1.16 mmol/kg dry muscle, respectively) despite the greater potential for fat oxidation in type I fibers. However, the acetylcarnitine concentration was slightly greater in type I fibers (P < 0.01). During exercise, acetylcarnitine accumulation occurred in both muscle fiber types, but accumulation was greatest in type I fibers (P < 0.005). Correspondingly, the concentration of free carnitine was significantly lower in type I fibers at the end of exercise (P < 0.001). The sum of free carnitine and acetylcarnitine concentrations in type I and II fibers at rest was similar and was unchanged by exercise. In conclusion, the findings of the present study support the suggestion that carnitine buffers excess acetyl group formation during exercise and that this occurs in both type I and II fibers. However, the greater accumulation of acetylcarnitine in type I fibers during prolonged exercise probably reflects the greater mitochondrial content of this fiber type.

scholarly journals Identification of Differentially Expressed Genes in Different Types of Broiler Skeletal Muscle Fibers Using the RNA-seq Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Han Wang ◽  
Zhonghao Shen ◽  
Xiaolong Zhou ◽  
Songbai Yang ◽  
Feifei Yan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Differentially Expressed Genes ◽  
Muscle Fiber ◽  
Muscle Development ◽  
Skeletal Muscle Fiber ◽  
Differentially Expressed ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Rna Seq

The difference in muscle fiber types is very important to the muscle development and meat quality of broilers. At present, the molecular regulation mechanisms of skeletal muscle fiber-type transformation in broilers are still unclear. In this study, differentially expressed genes between breast and leg muscles in broilers were analyzed using RNA-seq. A total of 767 DEGs were identified. Compared with leg muscle, there were 429 upregulated genes and 338 downregulated genes in breast muscle. Gene Ontology (GO) enrichment indicated that these DEGs were mainly involved in cellular processes, single organism processes, cells, and cellular components, as well as binding and catalytic activity. KEGG analysis shows that a total of 230 DEGs were mapped to 126 KEGG pathways and significantly enriched in the four pathways of glycolysis/gluconeogenesis, starch and sucrose metabolism, insulin signalling pathways, and the biosynthesis of amino acids. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the differential expression of 7 selected DEGs, and the results were consistent with RNA-seq data. In addition, the expression profile of MyHC isoforms in chicken skeletal muscle cells showed that with the extension of differentiation time, the expression of fast fiber subunits (types IIA and IIB) gradually increased, while slow muscle fiber subunits (type I) showed a downward trend after 4 days of differentiation. The differential genes screened in this study will provide some new ideas for further understanding the molecular mechanism of skeletal muscle fiber transformation in broilers.

scholarly journals Properties of skeletal muscle in the teleost Sternopygus macrurus are unaffected by short-term electrical inactivity

2016 ◽  
Vol 48 (9) ◽  
pp. 699-710 ◽  
Author(s):  
Robert Güth ◽  
Alexander Chaidez ◽  
Manoj P. Samanta ◽  
Graciela A. Unguez
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Electrical Activity ◽  
Muscle Fiber ◽  
Model Systems ◽  
Control Fish ◽  
Type I ◽  
Fiber Types ◽  
Spinal Transection ◽  
Fiber Size

Skeletal muscle is distinguished from other tissues on the basis of its shape, biochemistry, and physiological function. Based on mammalian studies, fiber size, fiber types, and gene expression profiles are regulated, in part, by the electrical activity exerted by the nervous system. To address whether similar adaptations to changes in electrical activity in skeletal muscle occur in teleosts, we studied these phenotypic properties of ventral muscle in the electric fish Sternopygus macrurus following 2 and 5 days of electrical inactivation by spinal transection. Our data show that morphological and biochemical properties of skeletal muscle remained largely unchanged after these treatments. Specifically, the distribution of type I and type II muscle fibers and the cross-sectional areas of these fiber types observed in control fish remained unaltered after each spinal transection survival period. This response to electrical inactivation was generally reflected at the transcript level in real-time PCR and RNA-seq data by showing little effect on the transcript levels of genes associated with muscle fiber type differentiation and plasticity, the sarcomere complex, and pathways implicated in the regulation of muscle fiber size. Data from this first study characterizing the acute influence of neural activity on muscle mass and sarcomere gene expression in a teleost are discussed in the context of comparative studies in mammalian model systems and vertebrate species from different lineages.

Relationship between muscle fiber characteristics and meat quality parameters in Turkish native goat breeds

2018 ◽  
Author(s):  
Emre Sirin
Keyword(s):  
Meat Quality ◽  
Muscle Fiber ◽  
Quality Parameters ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Fiber Number ◽  
Weaning Age ◽  
Positive Correlations

This study was conducted to determine muscle fiber characteristics and their effect on some meat quality parameters in Longissimus dorsi (LD) and Semitendinosus (ST) muscles from kids of some Turkish native goat breeds. Male kids of Hair (n=6), Angora (n=6), Kilis (n=6) and Honamli (n=6) (pure breeds) were used as experimental animals. All kids were slaughtered at 3 months of weaning age and muscles samples were collected for determination of type I, IIA and IIB muscle fibers and some meat quality parameters. It was found that type IIA fiber number of Hair and Honamli kids were higher than those of other breeds in LD muscle. Similarly, Hair kids had higher number of (P less than 0.05) type IIA in ST muscle compared to other breeds. Generally, there were negative correlations between tenderness, pH and number of muscle fiber types in LD and ST muscles of all breeds (P less than0.05). Also, there were positive correlations between intra muscular fat and number of muscle fiber types in LD muscles of all breeds (P less than 0.05). Conclusively, kids of Turkish native goat breeds had different muscle fiber characteristics which can affect meat quality.

scholarly journals Metabolic and morphometric profile of muscle fibers in chronic hemodialysis patients

2012 ◽  
Vol 112 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Michael I. Lewis ◽  
Mario Fournier ◽  
Huiyuan Wang ◽  
Thomas W. Storer ◽  
Richard Casaburi ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Muscle Fibers ◽  
Exercise Intolerance ◽  
Maintenance Hemodialysis ◽  
Muscle Fiber Types ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Fiber Types ◽  
Dense Matrix ◽  
Individual Fiber

Muscle weakness and effort intolerance are common in maintenance hemodialysis (MHD) patients. This study characterized morphometric, histochemical, and biochemical properties of limb muscle in MHD patients compared with controls (CTL) with similar age, gender, and ethnicity. Vastus lateralis muscle biopsies were obtained from 60 MHD patients, 1 day after dialysis, and from 21 CTL. Muscle fiber types and capillaries were identified immunohistochemically. Individual muscle fiber cross-sectional areas (CSA) were quantified. Individual fiber oxidative capacities were determined (microdensitometric assay) to measure succinate dehydrogenase (SDH) activity. Mean CSAs of type I, IIA, and IIX fibers were 33, 26, and 28% larger in MHD patients compared with CTL. SDH activities for type I, IIA, and IIX fibers were reduced by 29, 40, and 47%, respectively, in MHD. Capillary to fiber ratio was increased by 11% in MHD. The number of capillaries surrounding individual fiber types were also increased (type I: 9%; IIA: 10%; IIX: 23%) in MHD patients. However, capillary density (capillaries per unit muscle fiber area) was reduced by 34% in MHD patients, compared with CTL. Ultrastuctural analysis revealed swollen mitochondria with dense matrix in MHD patients. These results highlight impaired oxidative capacity and capillarity in MHD patients. This would be expected to impair energy production as well as substrate and oxygen delivery and exchange and contribute to exercise intolerance. The enlarged CSA of muscle fibers may, in part, be accounted for by edema. We speculate that these changes contribute to reduce limb strength in MHD patients by reducing specific force.

scholarly journals Pembentukan Pustaka Genom, Resekuensing, dan Identifikasi SNP Berdasarkan Sekuen Genom Total Genotipe Kedelai Indonesia

2016 ◽  
Vol 11 (1) ◽  
pp. 7 ◽  
Author(s):  
I Made Tasma ◽  
Dani Satyawan ◽  
Habib Rijzaani
Keyword(s):  
Genomic Library ◽  
Genomic Sequence ◽  
Sequence Data ◽  
Soybean Genome ◽  
Quality Analysis ◽  
Reference Sequence ◽  
Sequencing Error ◽  
Whole Genome ◽  
Genome Wide ◽  
Soybean Genotypes

<p>Resequencing of the soybean genome facilitates SNP marker discoveries useful for supporting the national soybean breeding<br />programs. The objectives of the present study were to construct soybean genomic libraries, to resequence the whole genome of<br />five Indonesian soybean genotypes, and to identify SNPs based on the resequence data. The studies consisted of genomic<br />library construction and quality analysis, resequencing the whole-genome of five soybean genotypes, and genome-wide SNP<br />identification based on alignment of the resequence data with reference sequence, Williams 82. The five Indonesian soybean<br />genotypes were Tambora, Grobogan, B3293, Malabar, and Davros. The results showed that soybean genomic library was<br />successfully constructed having the size of 400 bp with library concentrations range from 21.2–64.5 ng/μl. Resequencing of the<br />libraries resulted in 50.1 x 109 bp total genomic sequence. The quality of genomic library and sequence data resulted from this<br />study was high as indicated by Q score of 88.6% with low sequencing error of only 0.97%. Bioinformatic analysis resulted in a<br />total of 2,597,286 SNPs, 257,598 insertions, and 202,157 deletions. Of the total SNPs identified, only 95,207 SNPs (2.15%) were<br />located within exons. Among those, 49,926 SNPs caused missense mutation and 1,535 SNPs caused nonsense mutation. SNPs<br />resulted from this study upon verification will be very useful for genome-wide SNP chip development of the soybean genome to<br />accelerate breeding program of the soybean.</p>

Capillarity and fiber types in the cremaster muscle of rat and hamster

1983 ◽  
Vol 245 (2) ◽  
pp. H368-H374 ◽  
Author(s):  
I. H. Sarelius ◽  
L. C. Maxwell ◽  
S. D. Gray ◽  
B. R. Duling
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Succinic Dehydrogenase ◽  
Capillary Density ◽  
Type I ◽  
Fiber Types ◽  
Cremaster Muscle ◽  
Muscle Area ◽  
Cross Sectional

We determined muscle fiber type and capillarity in cremaster muscle samples from rats and hamsters of different ages. Histochemical estimation of oxidative capacity was made from the activity of either nicotinamide dinucleotide tetrazolium reductase (NADH-TR) or succinic dehydrogenase (SDH), and fibers were termed fast or slow from myofibrillar ATPase activity. Fibers were classified as type I (low ATPase, high NADH-TR/SDH), type IIa (high ATPase, high SDH/NADH-TR), type IIb (high ATPase, low SDH/NADH-TR), or type IIc (no acid reversal of ATPase, high NADH-TR). Type IIb fibers accounted for 60-80% of the muscle area in both species at all ages. The principal change with maturation was muscle fiber hypertrophy. Mean cross-sectional fiber area increased from 488 +/- 70 (SE) and 453 +/- 19 micron2 in young hamsters and rats, respectively, to 1,255 +/- 99 and 1,540 +/- 101 micron2 in adults. Capillary density (no. of capillaries/mm2 tissue) paralleled fiber hypertrophy; it decreased significantly with maturation from 684 +/- 60 (SE) to 228 +/- 26/mm2 in hamsters and from 341 +/- 15 to 213 +/- 15/mm2 in rats. In vitro estimates of capillary density are compared with previously obtained in vivo data (31), and sources of error are identified. We conclude that reported differences in microvascular function in the cremaster muscle in vivo during maturation or between species cannot be ascribed to changes in muscle composition.

Histochemical and Morphometric Evaluation of Skeletal Muscle of Cachectic Sheep

1981 ◽  
Vol 18 (3) ◽  
pp. 279-298 ◽  
Author(s):  
T. J. Hulland
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Succinic Dehydrogenase ◽  
Adult Life ◽  
Biological Behavior ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Atrophy And Hypertrophy ◽  
Type I Fibers

Skeletal muscle of sheep was examined histochemically in an attempt to define muscle fiber populations capable of distinctive biological behavior. ATPase at alkaline and acid pH, NADH-TR, and succinic dehydrogenase showed at least 12 fiber types, but only three often enough to be considered biologically important muscle fiber populations. The proportions of the three major types altered during early life, but not perceptibly during adult life. Proportions of Type I and Type II fibers were different, sometimes significantly, from breed to breed. Histochemical techniques and morphometric analyses of fiber cross-sectional area were used to study muscle fiber changes in moderate to marked cachectic atrophy. Progressive reduction of gross muscle volume was attended by complex interrelationships between the two major muscle fiber types, including alternate episodes of atrophy and hypertrophy, resulting in marked inequality of mean fiber size between the fiber types. The patterns appeared to be different but characteristic for each muscle. The usual pattern of cachectic atrophy shows atrophy resistance of Type I fibers, but here a Type II-dominant atrophy also was seen. It is concluded that the large muscle fibers often seen in advanced cachectic atrophy are those Type I fibers that are more labile in both atrophy and hypertrophy than most.

Inducible isoform of HSP70 is constitutively expressed in a muscle fiber type specific pattern

1991 ◽  
Vol 261 (5) ◽  
pp. C774-C779 ◽  
Author(s):  
M. Locke ◽  
E. G. Noble ◽  
B. G. Atkinson
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Constitutive Expression ◽  
Muscle Fiber Types ◽  
Type I ◽  
Fiber Types ◽  
Nylon Membrane ◽  
White Gastrocnemius

The most prominent group of stress or heat-shock proteins (HSPs) has an Mr of approximately 70,000 and is collectively referred to as the HSP70 family. The extent of stress inducibility and subcellular location of the various HSP70 isoforms differ, but all appear to be involved with ATP-dependent stabilization or solubilization of proteins. One isoform, termed the inducible isoform of HSP70 (HSP72i), is normally absent in unstressed cells. In a previous study, we detected a protein corresponding in Mr and pI to HSP72i in unstressed rat muscle. Therefore, it was of interest to determine if this expression in unstressed muscle cells is general or confined to specific muscle fiber types. To answer this question we have employed various rat hindlimb muscles that differ in fiber type proportion from predominantly type I (soleus) to predominantly type IIB (white gastrocnemius). Proteins from muscle homogenates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted to a nylon membrane, probed with a monoclonal antibody for HSP72i, and visualized using an alkaline phosphatase-conjugated secondary antibody. Immunoblot analyses demonstrate the constitutive expression of HSP72i in rat muscles comprised primarily of type I muscle fibers (soleus), but not in muscles comprised primarily of type IIB fibers (white gastrocnemius). In muscles of mixed fiber type, HSP72i content is roughly proportional to the percentage of type I fibers. These results substantiate that unstressed rat muscles express the inducible HSP72 isoform and demonstrate that its constitutive expression is proportional to the type I muscle fiber composition.

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