• Asian-Australasian Journal of Animal Sciences
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• v.28 no.8
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• pp.1171-1177
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• 2015

The objective of this study was to establish the optimum protocol for the isolation and culture of porcine muscle satellite cells. Mononuclear muscle satellite cells are a kind of adult stem cell, which is located between the basal lamina and sarcolemma of muscle fibers and is the primary source of myogenic precursor cells in postnatal muscle. Muscle satellite cells are a useful model to investigate the mechanisms of muscle growth and development. Although the isolation and culture protocols of muscle satellite cells in some species (e.g. mouse) have been established successfully, the culture system for porcine muscle satellite cells is very limited. In this study, we optimized the isolation procedure of porcine muscle satellite cells and elaborated the isolation and culture process in detail. Furthermore, we characterized the porcine muscle satellite cells using the immunofluorecence. Our study provides a reference for the isolation of porcine muscle satellite cells and will be useful for studying the molecular mechanisms in these cells.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1430-1434
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• 2009

The present study used the liquid extraction pretreatment method and developed a liquid chromatographyultraviolet detector (LC-UV) for the simultaneous determination of 14 sulfonamides (SAs) residues in porcine and chicken muscle. Linearity within a range of $50-150\;{\mu}g/kg$ was obtained with the correlation coefficient ($r^2$) of 0.9673-0.9997. The mean recovery of SAs was 55.9-109.7% (relative standard deviations; RSDs 1.7-17.3%) in porcine muscle and 52.8-112.4% (RSDs 2.3-16.9%) in chicken muscle. The limits of detection (LODs) and limits of quantification (LOQs) were 2-32 and $7-96\;{\mu}g/kg$ in porcine muscle, and 4-32 and $13-97\;{\mu}g/kg$ in chicken muscle, respectively. These values were lower than the maximum residue limits (MRLs) established by the European Union. The sum of all SAs residues present should be less than $100\;{\mu}g/kg$.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.443-449
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• 1986

In order to investigate the general characteristics of ATPase and ATPase thermostability between porcine white muscle and red muscle, myofibrillar proteins were prepared and compared their physicochemical characteristics. SDS-polyacrylamide gel electrophoretic analyses showed that a protein band of 30,000 daltons was detected noticeably in myofibril from red muscle, but negligibly in myofibril from white muscle. The noticeable differences were found between porcine white muscle and red muscle for the activities of EDTA-ATPase, Ca-ATPase and Mg-ATPase. Myofibrillar proteins from white muscle showed higher thermostability than those from red muscle. Thermodynamic parameters, enthalpy $({\Delta}H^#)$, entropy $({\Delta}S^#)$, etc., showed characteristic variations between porcine white muscle and red muscle.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.132-144
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• 2020

The aim of this study was to optimize staining procedures for muscle fiber typing efficiently and rapidly in bovine and porcine skeletal muscles, such as longissimus thoracis, psoas major, semimembranosus, and semitendinosus muscles. The commercially available monoclonal anti-myosin heavy chain (MHC) antibodies and fluorescent dye-conjugated secondary antibodies were applied to immunofluorescence histology. Two different procedures, such as cocktail and serial staining, were adopted to immunofluorescence analysis. In bovine muscles, three pure types (I, IIA, and IIX) and one hybrid type, IIA+IIX, were identified by the cocktail procedure with a combination of BA-F8, SC-71, BF-35, and 6H1 anti-MHC antibodies. Porcine muscle fibers were typed into four pure types (I, IIA, IIX, and IIB) and two hybrid types (IIA+IIX and IIX+IIB) by a serial procedure with a combination of BA-F8, SC-71, BF-35, and BF-F3. Unlike for bovine muscle, the cocktail procedure was not recommended in porcine muscle fiber typing because of the abnormal reactivity of SC-71 antibody under cocktail procedure. Within the four antibodies, combinations of two or more anti-MHC antibodies allowed us to distinguish pure fiber types or all fiber types including hybrid types. Application of other secondary antibodies conjugated with different fluorescent dyes allowed us to get improved image resolution that clearly distinguished hybrid fibers. Muscle fiber characteristics differed depending on species and muscle types.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.192-199
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• 2001

The objective of this study was to investigate the effects of hot- and cold-boning on sarcomere length, drip loss and protein solubility of post-rigor porcine longissimus muscle. A total of ten pigs(borrow, 100$\pm$5 kg) were randomly selected at a commercial plant and the carcasses were split in half after slaughter. The longissimus muscle of the left side was dissected and chilled at 0$^{\circ}C$ after trimming of subcutaneous fat whereas the right side carcasses were served for cold-boning after chilling for 24 hrs. The temperature, pH and sarcomere length of porcine longissimus muscle were measured at postmortem 1, 3, 6, 12 and 24 hours. Drip loss, cooking loss, Minolta L*a*b*, shear force and protein solubility were measured at postmortem 24 hrs. The pH of cold-boning samples was rapidly decreased whereas temperature and sarcomere length of hot-boning samples were rapidly decreased during 24 hrs of chilling. Hot-boning muscles showed significantly (P<0.05) higher pHu and shorter sarcomere compared with cold boning muscles because of cold shortening. However, there were no significant differences in drip loss, cooking loss and shear force value between hot- and cold boned samples. The samples of hot-boning showed lower Minolta L* value and higher sarcoplasmic protein solubility compared with cold boned samples. These results suggest that the pale color changing of porcine longissimus muscle could be inhibited by hot-boning due to rapid chilling of the muscle although sarcomere length could be shortened because of cold shortening. Also these results show that hot-boning of porcine carcass could have a high protein solubility without negative effects of drip loss or tenderness of porcine longissimus muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1620-1632
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• 2017

Objective: This study evaluated the effects of a traditional Chinese medicine formula (TCMF) on muscle fiber characteristics in finishing pigs and the effects of the formula's extract (distilled water, ethyl acetate and petroleum ether extraction) on porcine cell proliferation and isoforms of myosin heavy chain (MyHC) gene expression in myocytes. Methods: In a completely randomized design, ninety pigs were assigned to three diets with five replications per treatment and six pigs per pen. The diets included the basal diet (control group), TCMF1 (basal diet+2.5 g/kg TCMF) and TCMF2 (basal diet+5 g/kg TCMF). The psoas major muscle was obtained from pigs at the end of the experiment. Muscle fiber characteristics in the psoas major muscle were analyzed using myosin ATPase staining. Cell proliferation was measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) dye and cytometry. Isoforms of MyHC gene expression were detected by real-time quantitative polymerase chain reaction. Results: The final body weight and carcass weight of finishing pigs were increased by TCMF1 (p<0.05), while the psoas major muscle cross-sectional area was increased by TCMF (p<0.05). The cross-sectional area and diameter of psoas major muscle fiber Ι, IIA, and IIB were increased by TCMF2 (p<0.05). The cross-sectional area and fiber diameter of psoas major muscle fiber IIA and IIB were increased by diet supplementation with TCMF1 (p<0.05). Psoas major muscle fiber IIA and IIB fiber density from the pigs fed the TCMF1 diet and the type IIB fiber density from the pigs fed the TCMF2 diet were lower compared to pigs fed the control diet (p<0.05). Pigs fed TCMF2 had a higher composition of type Ι fiber and a lower percentage of type IIB fiber in the psoas major muscle (p<0.05). The expression levels of MyHC Ι, MyHC IIa, and MyHC IIx mRNA increased and the amount of MyHC IIb mRNA decreased in the psoas major muscle from TCMF2, whereas MyHC Ι and MyHC IIx mRNA increased in the psoas major muscle from TCMF1 (p<0.05). Peroxisome proliferator-activated receptor ${\gamma}$ $coactivator-1{\alpha}$ and CaN mRNA expression in the psoas major muscle were up-regulated by TCMF (p<0.05). Porcine skeletal muscle satellite cell proliferation was promoted by $4{\mu}g/mL$ and $20{\mu}g/mL$ TCMF water extraction (p<0.05). Both $1{\mu}g/mL$ and $5{\mu}g/mL$ of TCMF water extraction increased MyHC IIa, MyHC IIb, and MyHC IIx mRNA expression in porcine myocytes (p<0.05), while MyHC Ι mRNA expression in porcine myocytes was decreased by $5{\mu}g/mL$ TCMF water extraction (p<0.05). Porcine myocyte MyHC Ι and MyHC IIx mRNA expression were increased, and MyHC IIa and MyHC IIb mRNA expression were down-regulated by $5{\mu}g/mL$ TCMF ethyl acetate extraction (p<0.05). MyHC Ι and MyHC IIa mRNA expression in porcine myocytes were increased, and the MyHC IIb mRNA expression was decreased by $1{\mu}g/mL$ TCMF ethyl acetate extraction (p<0.05). Four isoforms of MyHC mRNA expression in porcine myocytes were reduced by $5{\mu}g/mL$ TCMF petroleum ether extraction (p<0.05). MyHC IIa mRNA expression in porcine myocytes increased and MyHC IIb mRNA expression decreased by $1{\mu}g/mL$ in a TCMF petroleum ether extraction (p<0.05). Conclusion: These results indicated that TCMF amplified the psoas major muscle cross-sectional area through changing muscle fiber characteristics in finishing pigs. This effect was confirmed as TCMF extraction promoted porcine cell proliferation and affected isoforms of MyHC gene expression in myocytes.

• BMB Reports
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• v.42 no.6
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• pp.338-343
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• 2009

The Wnt/$\beta$-catenin signaling pathway alters adipocyte differentiation by inhibiting adipogenic gene expression. $\beta$-catenin plays a central role in the Wnt/$\beta$-catenin signaling pathway. In this study, we revealed that tumour necrosis factor-$\alpha$ (TNF-$\alpha$), a potential negative regulator of adipocyte differentiation, inhibits porcine adipogenesis through activation of the Wnt/$\beta$-catenin signaling pathway. Under the optimal concentration of TNF-$\alpha$, the intracellular $\beta$-catenin protein was stabilized. Thus, the intracellular lipid accumulation of porcine preadipocyte was suppressed and the expression of important adipocyte marker genes, including peroxisome proliferator-activated receptor-$\gamma$ (PPAR$\gamma$) and CCAAT/enhancer binding protein-$\alpha$ (C/EBP$\alpha$), were inhibited. However, a loss of $\beta$-catenin in porcine preadipocytes enhanced the adipogenic differentiation and attenuated TNF-$\alpha$ induced anti-adipogenesis. Taken together, this study indicated that TNF-$\alpha$ inhibits adipogenesis through stabilization of $\beta$-catenin protein in porcine preadipocytes.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.423-429
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• 2005

Properties of pant surimi derived from porcine longissimus muscle were investigated Rapid glycolysis of muscle reduced yield $\%$ of water-washed pork and moisture $\%$ of pent surimi because of ie lower ultimate pH. Gel Hardness was significantly (p<0.05) higher in pork surimi from rapid glycolysis muscle, but springiness was higher (p<0.05) in pork surimi from normal glycolysis muscle. SDS-PAGE pattern showed denaturation of sarcoplasmic proteins onto myofibrillar proteins in rapid glycolysis muscle, resulted in dark color and hard texture of pork surimi. Color and texture of gels were related with water-holding capacity of muscle proteins and moisture $\%$ in gel matrix. Results imply that glycolysis rate of porcine muscle at postmortem could affect gel properties of pork surimi, and muscle with rapid glycolysis muscle could produce a hard texture of pork surimi and dark color.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.953-957
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• 2006

The eukaryotic elongation factor 1 A (EEF1A) participates in protein synthesis by forming the eEF1A GTP tRNA complex to deliver aminoacyl-tRNA to the A site of ribosomes. This study described cDNA sequences and partial genomic structure of porcine EEF1A1. The porcine EEF1A1 gene encoded a protein with 462 amino acids, which shared complete homology with human, chimpanzee and dog. The temporal expression pattern showed the diversity of EEF1A1 level in mRNA was relatively minor in prenatal embryo skeletal muscle, however, the expression decreased during aging after birth in skeletal muscle of the Chinese Tongcheng pig. The spatial expression patterns indicated that the gene expressed in skeletal muscle, heart, lung, liver, kidney, fat and spleen. In addition, we assigned the gene to porcine chromosome 1 using a radiation hybrid panel.

• Molecules and Cells
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• v.37 no.4
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• pp.302-306
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• 2014

Myostatin represses muscle growth by negatively regulating the number and size of muscle fibers. Myostatin loss-of-function can result in the double-muscling phenotype and increased muscle mass. Thus, knockout of myostatin gene could improve the quality of meat from mammals. In the present study, zinc finger nucleases, a useful tool for generating gene knockout animals, were designed to target exon 1 of the myostatin gene. The designed ZFNs were introduced into porcine primary fibroblasts and early implantation embryos via electroporation and microinjection, respectively. Mutations around the ZFNs target site were detected in both primary fibroblasts and blastocysts. The proportion of mutant fibroblast cells and blastocyst was 4.81% and 5.31%, respectively. Thus, ZFNs can be used to knockout myostatin in porcine primary fibroblasts and early implantation embryos.