• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.1037-1043
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• 2016

Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.782-787
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• 2015

The myogenic regulatory factors is a family of transcription factors that play a key role in the development of skeletal muscle fibers, which are the main factors to affect the meat taste and texture. In the present study, we performed candidate gene analysis to identify single-nucleotide polymorphisms in the MyoD, Myf5, MyoG, and Mrf4 genes using polymerase chain reaction-single strand conformation polymorphism in 360 Erlang Mountain Chickens from three different housing systems (cage, pen, and free-range). The general linear model procedure was used to estimate the statistical significance of association between combined genotypes and muscle fiber traits of chickens. Two polymorphisms (g.39928301T>G and g.11579368C>T) were detected in the Mrf4 and MyoD gene, respectively. The diameters of thigh and pectoralis muscle fibers were higher in birds with the combined genotypes of GG-TT and TTCT (p<0.05). Moreover, the interaction between housing system and combined genotypes has no significant effect on the traits of muscle fiber (p>0.05). Our findings suggest that the combined genotypes of TT-CT and GG-TT might be advantageous for muscle fiber traits, and could be the potential genetic markers for breeding program in Erlang Mountain Chickens.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.159-168
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• 2008

Objectives : The present study has been undertaken to investigate the effects of Dipsaci Radix on Muscle Fiber Atrophy and MyoD Expression in Gastrocnemius of MCAO Rats Methods : In order to investigate effects of Dipsaci radix on the skeletal muscle atrophy following stroke, cerebral infarct was induced by the middle cerebral artery occlusion (MCAO) in the rats. Water extract of Dipsaci radix (184.4 mg/100 g) was treated for 4 weeks, once a day orally, after the MCAO. Effects were evaluated with muscle fiber type composition and cross-sectioned area of muscle fibers in gastrocnemius of the unaffected & affected hind limbs. And MyoD protein expression in gastrocnemius was demonstrated with immunohistochemistry and western blotting. Results : Obtained results were as follows; 1. Infarct volume was not attenuated by Dipsaci radix treatment in the MCAO rats. 2. At the affected-side hind limb of the MCAO rats, the increase of type-I fibers and the decrease of type-II fibers were induced by Dipsaci radix treatment. 3. At the affected-side hind limb of the MCAO rats, decreases of cross-sectioned areas of type-I and type-II fibers were attenuated by Dipsaci radix treatment. 4. At the affected-side hind limb of the MCAO rats, MyoD positive cells were increased by Dipsaci radix treatment. 5. At the affected-side hind limb of the MCAO rats, MyoD expressions were increased by Dipsaci radix treatment. Conclusions : These results suggest that Dipsaci radix has a protective effect against muscle atrophy, through the inhibition of the muscle cell apoptosis, following the central nervous system demage.

• Animal Bioscience
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• v.35 no.4
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• pp.614-623
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• 2022

Objective: The objective of this study was to investigate the effects of sheep slaughter age on myogenic characteristics in skeletal muscle satellite cells (SMSCs). Methods: Primary SMSCs were isolated from hind leg biceps femoris muscles of Wurank lambs (slaughtered at three months, Mth-3) and adults (slaughtered at fifteen months, Mth-15). SMSCs were selected by morphological observation and fluorescence staining. Myogenic regulatory factors (MRF) and myosin heavy chain (MyHC) expressions of SMSCs were analyzed on days 1, 3, 4, and 5. Results: The expressions of myogenic factor 5 (Myf5), myogenic differentiation (MyoD), Myf6, and myogenin (MyoG) in Mth-15 were significantly higher in Mth-15 than in Mth-3 on days 1, 3, and 4 (p<0.05). However, MyoG expression in Mth-15 was significantly lower than in Mth-3 on day 5 (p<0.05). The expressions of MyHC I, MyHC IIa, and MyHC IIx in Mth-15 were significantly higher than in Mth-3 on days 1 and 3 (p<0.05), and MyHC IIb were significantly lower than in Mth-3 on days 3 and 4 (p<0.05). In contrast, the expression of MyHC IIx in Mth-15 was significantly lower and MyHC IIb was significantly higher than in Mth-3 on days 5 (p<0.05). Conclusion: The slaughter age altered the expression of MRFs and MyHCs in SMSCs while differentiation, which caused the variation of myogenic characteristics, and thus may affect the meat quality of Wurank sheep.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.78-83
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• 2001

Phytase (myo-inositol hexakisphosphate phosphohydrolase: EC 3.1.3.8) hydrolyzes phytic acid (myo-inositol hexakisphosphate) to myo-inositol and monophosphates. In order to obtain phytase producing bacteria, many samples were collected from various soils. Among thirty-five phytase-producing strains, YH100 showed the highest phytase activity. In order to identify the selected YHlOO strain, the morphological and physiological characteristics were examined according to the method of Bergey's manual by 168 rRNA sequence, cellular fatty acids profile, O+C contents and physiological test using API 20E kit. The strain YH100 identified to be a genus of Enterobacter cloacae and was named as Enterobacter cloacae YHlOO. Optimum medium for the phytase production by the Entemhacter c!o([we YHlOO was composed of 2.0%(w/v) glucose, 1.0%(w/v) peptone, 1.0%(w/v) beef extract, 0.1 %(w/v) KCI. and 0.1 %( w/v) sodium phytate.

• Molecules and Cells
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• v.38 no.9
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• pp.781-788
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• 2015

Mutations of MYO15A are generally known to cause severe to profound hearing loss throughout all frequencies. Here, we found two novel MYO15A mutations, c.3871C>T (p.L1291F) and c.5835T>G (p.Y1945X) in an affected individual carrying congenital profound sensorineural hearing loss (SNHL) through targeted resequencing of 134 known deafness genes. The variant, p.L1291F and p.Y1945X, resided in the myosin motor and IQ2 domains, respectively. The p.L1291F variant was predicted to affect the structure of the actin-binding site from three-dimensional protein modeling, thereby interfering with the correct interaction between actin and myosin. From the literature analysis, mutations in the N-terminal domain were more frequently associated with residual hearing at low frequencies than mutations in the other regions of this gene. Therefore we suggest a hypothetical genotype-phenotype correlation whereby MYO15A mutations that affect domains other than the N-terminal domain, lead to profound SNHL throughout all frequencies and mutations that affect the N-terminal domain, result in residual hearing at low frequencies. This genotype-phenotype correlation suggests that preservation of residual hearing during auditory rehabilitation like cochlear implantation should be intended for those who carry mutations in the N-terminal domain and that individuals with mutations elsewhere in MYO15A require early cochlear implantation to timely initiate speech development.

• BMB Reports
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• v.55 no.2
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• pp.104-109
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• 2022

Skeletal myogenesis is essential to keep muscle mass and integrity, and impaired myogenesis is closely related to the etiology of muscle wasting. Recently, miR-141-3p has been shown to be induced under various conditions associated with muscle wasting, such as aging, oxidative stress, and mitochondrial dysfunction. However, the functional significance and mechanism of miR-141-3p in myogenic differentiation have not been explored to date. In this study, we investigated the roles of miR-141-3p on CFL2 expression, proliferation, and myogenic differentiation in C2C12 myoblasts. MiR-141-3p appeared to target the 3'UTR of CFL2 directly and suppressed the expression of CFL2, an essential factor for actin filament (F-actin) dynamics. Transfection of miR-141-3p mimic in myoblasts increased F-actin formation and augmented nuclear Yes-associated protein (YAP), a key component of mechanotransduction. Furthermore, miR-141-3p mimic increased myoblast proliferation and promoted cell cycle progression throughout the S and G2/M phases. Consequently, miR-141-3p mimic led to significant suppressions of myogenic factors expression, such as MyoD, MyoG, and MyHC, and hindered the myogenic differentiation of myoblasts. Thus, this study reveals the crucial role of miR-141-3p in myogenic differentiation via CFL2-YAP-mediated mechanotransduction and provides implications of miRNA-mediated myogenic regulation in skeletal muscle homeostasis.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.69-76
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• 2011

This study describes the effect of myo-inositol on sustained cell division and plant regeneration from cotyledon-derived protoplast of cabbage (Brassica oleracea var. capitata). Freshly isolated protoplasts were cultured in modified Murashige and Skoog (MS) medium removed ammonia ions and containing $0.4\;mg\;l^{-1}$ thiamine HCl, $100\;mg\;l^{-1}$ myo-inositol, $2\;mgl^{-1}$ 2,4-D, $0.5\;mgl^{-1}$ BA, $30\;gl^{-1}$ sucrose and several concentrations of myo-inositol (2, 4, 6, 8, 10% (w/v)) as an osmotic stabilizer. After 3 weeks of culture in the dark at $25^{\circ}C$, the plating efficiency of cabbage protoplasts reached to $22.5{\pm}2.9%$ when cultured in modified MS medium supplemented with $2\;mgl^{-1}$ 2,4-D, $0.5\;mgl^{-1}$ BA, $30\;gl^{-1}$ sucrose and 8% (w/v) of myo-inositol at a density of $2{\times}10^5$ protoplasts/ml. Rapidly growing cell colonies after 3 weeks of culture were transferred to the same culture medium removed osmoticum. To induce shoot regeneration from calluses, calluses with about 2 mm in diameter were transferred to the MS medium containing $2\;mgl^{-1}$ BA and $0.5\;mgl^{-1}$ NAA. After further three weeks of incubation onto the medium in the light, green shoots were formed on the surface of calluses at a frequency of 30%. Upon transfer to half-strength MS basal medium, roots were formed onto the bottom of regenerated shoots without auxin treatments. These regenerated plantlets were successfully acclimatized to soil transfer, grown to normal mature plants. The cabbage protoplast culture system established in this study could be applied for production of somatic hybrids or cybrids by asymmetric protoplast fusion and mass proliferation of elite somatic clones of cabbage.

• Journal of Life Science
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• v.31 no.5
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• pp.453-463
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• 2021

Hearing loss is a group of clinically and genetically heterogeneous disorders characterized by congenital- to adult-onset deafness with frequent additional symptoms such as myopathy, nephropathy, and optic disorders. It is commonly divided into two types: syndromic, with no other symptoms, and nonsyndromic, with other symptoms. Autosomal recessive hearing loss is relatively frequent in Pakistan, which may be due in part to frequent consanguineous marriages. This study was performed by whole exome sequencing to determine the genetic causes in two Pakistani consanguineous families with autosomal recessive hearing loss. We identified a pathogenic homozygous variant (p.Leu326Gln in MYO7A) in a family with prelingual-onset hearing loss and two variants of uncertain significance (p.Val3094Ile in GPR98 and p.Asp56Gly in PLA2G6) in a family with early-onset hearing loss concurrent with muscular atrophy. The missense mutations in MYO7A and PLA2G6 were located in the highly conserved sites, and in silico analyses predicted pathogenicity, while the GPR98 mutation was located in the less conserved site, and most in silico analysis programs predicted its nonpathogenic effect. Homozygosity mapping showed that both alleles of the homozygous mutations identified in each family originated from a single founder; spread from this single source might be due to consanguineous marriages. This study will help provide exact molecular diagnosis and treatment for autosomal recessive hearing loss patients in Pakistan.

• The Journal of Internal Korean Medicine
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• v.40 no.1
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• pp.1-12
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• 2019

Objective: To investigate the effect of Alpiniae oxyphyllae fructus (AOF) on the alleviation of musculoskeletal disorders caused by aging, we conducted experiments on osteoporosis and muscle atrophy. Methods: The experimental group was classified into a control group, aging-elicited (AE) group and AOF group. The control group comprised 8-week-old Institute of Cancer Research (ICR) mice. The AE and AOF groups were ICR mice at 50 weeks of age. For the AE group, 10 mL of distilled water was administered once a day for 180 days without any treatment. An AOF extract (0.54 g/kg) was dissolved in distilled water and administered to the mice in the AOF group once a day for 180 days. Results: In the experiment on the alleviation of osteoporosis, the distribution of glucosaminoglycan in the bone matrix of the femoral bone was increased in the AOF group; moreover, the osteocalcin (OCN) positive reaction was increased and 8-OHdG positivity was decreased. In addition, AOF positively decreased RANKL, positively increased OPG, and positively decreased MMP-3. Muscle fiber loss in the endomysium following muscle degeneration of the quadriceps was reduced more in the AOF group compared with the AE group, and caspase-3 positive responses were also decreased. In addition, the 8-OHdG and p-lkB positivity in the AOF group decreased compared with the AE group, and the Myo-D positivity increased. Conclusion: We found that increasing bone formation alleviates osteoporosis, and that reducing bone loss alleviates muscle atrophy by reducing muscle loss and increasing muscle development.