Wnt gene expression in adult porcine longissimus dorsi and its association with muscle fiber type,energy metabolism,and meat quality

This study investigated the expression profiles of Writ genes in adult porcine Iongissimus dorsi （LD） from different porcine genotypes and their associations with meat quality. The results showed that Wnt5a gene expression level was the highest in Jinhua （JHP） pigs, followed by Zhongbai （ZBP）, DurocxZhongbai （DZB）, and Duroc×Yorkshire×Landrace （DYL） pigs, with significant differences between ZBP, DZB, and DYL （P〈0.05）. This genotypic order was reversed for Wnt7a, Wnt10b, and Wnt11 expression, with JHP and DYL having the lowest and highest expressive levels, respectively. Wnt5a expression was negatively correlated with pH,5 min and ApH （P〈0.01）, some glycolytic markers （P〈0.05）, and positively correlated with meat color （a＊）, shear force （SF） value （P〈0.05）, myosion heavy chain （MyHC） I mRNA proportion （P〈0.01）, turnover ratio of creatine phosphate （CP）, and creatine kinase （CK） activity （P〈0.05）. Opposite correlations were observed for Writ2, Wnt7a, Wnt10b, and Wnt11. These results revealed that Wnt5a, Wnt7a, Wnt10b, and Wnt11 gene expressions in adult porcine muscle contributed to differences between porcine genotypes and affected pork quality. Wnt5a gene expression could be beneficial for the formation of high quality pork by regulating muscle fiber types and postmortem energy metabolism.

Effects of Aerobic Exercise on the Intramuscular Lipid and Glycogen Content of Fiber Types in Soleus Muscles of Non-Alcoholic Steatohepatitis Model Rats

We studied the effects of exercise on muscle mitochondria, and lipid and glycogen content in non-alcoholic steatohepatitis (NASH) model rats. Male Sprague-Dawley rats were randomly separated into 3 groups: the control group was fed standard chow;the NASH group was fed a methionine-choline-deficient high-fat diet (MCD);the NASH-exercise group was fed the MCD and exercised three times a week. Exercise training consisted of continuous running for thirty minutes at a 13 m/min, 6° slope on a motor-driven rodent treadmill for 6 weeks. Mitochondria content in NASH group decreased in the both fiber types compared with those of the control group. As compared between the NASH and NASH-exercise groups, however, exercise not only promoted significant improvements in liver fibrosis and cirrhosis and triglyceride (TG) content but also increased mitochondria content in type I muscle fiber in particular. These data suggest that exercise improved hepatic steatosis in NASH model rats and can prevent the progression of NASH.

Dietary lycopene supplementation improves meat quality,antioxidant capacity and skeletal muscle fiber type transformation in finishing pigs

This study aimed to investigate effects of dietary lycopene supplementation on meat quality,antioxidant ability and muscle fiber type transformation in finishing pigs.In a 70-day experiment,18 DurocLandraceYorkshire barrows were randomly allocated to 3 dietary treatments including a basal diet supplemented with 0,100 and 200 mg/kg lycopene,respectively.Each dietary treatment had 6 replicates with one pig each.Results showed that dietary 200 mg/kg lycopene supplementation increased muscle redness a^(*)value,intramuscular fat and crude protein contents,and decreased muscle lightness L^(*)and yellowness b^(*)values(P<0.05),suggesting that addition of 200 mg/kg lycopene to the diet of finishing pigs improved color,nutritional value and juiciness of pork after slaughter.Results also showed that dietary lycopene supplementation enhanced antioxidant capacity of finishing pigs(P<0.05).Moreover,dietary supplementation of 200 mg/kg lycopene significantly increased slow myosin heavy chain(MyHC)protein level and slow-twitch fiber percentage,and decreased fast MyHC protein level and fast-twitch fiber percentage(P<0.05),suggesting that the addition of 200 mg/kg lycopene to the diet of finishing pigs promoted muscle fiber type conversion from fast-twitch to slow-twitch.Together,we provide the first evidence that dietary 200 mg/kg lycopene supplementation improves meat quality,enhances antioxidant capacity and promotes muscle fiber type transformation from fast-twitch to slow-twitch in finishing pigs.

Transcriptional regulatory circuits controlling muscle fiber type switching

Skeletal muscle fitness plays vital roles in human health and disease and is determined by developmental as well as physiological inputs. These inputs control and coordinate muscle fiber programs, including capacity for fuel burning, mitochondrial ATP production, and contraction. Recent studies have demonstrated crucial roles for nuclear receptors and their co-activators, and micro RNAs(mi RNAs) in the regulation of skeletal muscle energy metabolism and fiber type determination. In this review, we present recent progress in the study of nuclear receptor signaling and mi RNA networks in muscle fiber type switching. We also discuss the therapeutic potential of nuclear receptors and mi RNAs in disease states that are associated with loss of muscle fitness.

Targeted myostatin loss-of-function mutation increases type Ⅱ muscle fibers in Meishan pigs

Myostatin(MSTN) is a negative regulator of skeletal muscle growth and development. The skeletal muscle in MSTN^(-/-)mice is significantly hypertrophied, with muscle fiber type II increasing significantly while muscle fiber type I decreasing.However, it is still not clear how the skeletal muscle types change in MSTN^(-/-)pigs, and how the mechanism for MSTN regulates fiber types, especially in large animals like pigs. This study conducted a comprehensive analysis of the composition of skeletal muscle fibers in MSTN^(-/-)pigs produced in our laboratory. It was observed that, compared with wild-type(WT) pigs, both the total mass of skeletal muscle and type IIb muscle fibers increased significantly(P<0.01),while the type I and type IIa muscle fibers decreased significantly(P<0.01), in MSTN^(-/-)Meishan pigs. In addition, to explore the influence of MSTN on muscle fiber type and its regulation mechanism in the embryonic stage, this study selected a few genes(Myf5, Mef2 d, MyoD and Six1) associated with muscle fiber type and validated their expression by quantitative RT-PCR. Herein, it was found that Myh7, Myh2, Myh4 and Myh1 can be detected in the skeletal muscle of pigs at 65 days of gestation(dg). Compared with WT pigs, in MSTN^(-/-)Meishan pigs, Myh7 decreased significantly(P<0.01), while Myh4(P<0.001) and Myh1(P<0.05) increased significantly. Meanwhile, the increased expression of Myf5(P<0.05), Mef2 d(P<0.01) and Six1(P<0.05) in MSTN^(-/-)Meishan pigs suggested that MSTN should regulate the directional development of muscle fiber types in the early stage of embryonic development. Thus, at the embryonic stage, the type II muscle fibers began to increase in MSTN^(-/-)pigs. These results can provide valuable information not only for pig meat quality improvement, but also for the study of human skeletal muscle development and disease treatment.

Vitamin A regulates mitochondrial biogenesis and function through p38 MAPK‑PGC‑1α signaling pathway and alters the muscle fiber composition of sheep

Background Vitamin A(VA)and its metabolite,retinoic acid(RA),are of great interest for their wide range of physiological functions.However,the regulatory contribution of VA to mitochondrial and muscle fiber composition in sheep has not been reported.Method Lambs were injected with 0(control)or 7,500 IU VA palmitate into the biceps femoris muscle on d 2 after birth.At the age of 3 and 32 weeks,longissimus dorsi(LD)muscle samples were obtained to explore the effect of VA on myofiber type composition.In vitro,we investigated the effects of RA on myofiber type composition and intrinsic mechanisms.Results The proportion of type I myofiber was greatly increased in VA-treated sheep in LD muscle at harvest.VA greatly promoted mitochondrial biogenesis and function in LD muscle of sheep.Further exploration revealed that VA elevated PGC-1αmRNA and protein contents,and enhanced the level of p38 MAPK phosphorylation in LD muscle of sheep.In addition,the number of type I myofibers with RA treatment was significantly increased,and type IIx myofibers was significantly decreased in primary myoblasts.Consistent with in vivo experiment,RA significantly improved mitochondrial biogenesis and function in primary myoblasts of sheep.We then used si-PGC-1αto inhibit PGC-1αexpression and found that si-PGC-1αsignificantly abrogated RA-induced the formation of type I myofibers,mitochondrial biogenesis,MitoTracker staining intensity,UQCRC1 and ATP5A1 expression,SDH activity,and enhanced the level of type IIx muscle fibers.These data suggested that RA improved mitochondrial biogenesis and function by promoting PGC-1αexpression,and increased type I myofibers.In order to prove that the effect of RA on the level of PGC-1αis caused by p38 MAPK signaling,we inhibited the p38 MAPK signaling using a p38 MAPK inhibitor,which significantly reduced RA-induced PGC-1αand MyHC I levels.Conclusion VA promoted PGC-1αexpression through the p38 MAPK signaling pathway,improved mitochondrial biogenesis,and altered the composition of muscle fiber type.

Effect of Combination of Steel Fiber and MgO-type Expansive Agent on Properties of Concrete

The effect of combination of steel fiber and MgO-type expansive agent （MEA） on strength, air-permeability and porosity of concrete was investigated. The porosity and air-permeability of concrete were determined by method of evaporated water and Torrent permeability tester, respectively. Pore structures of mortars in concrete were analyzed using mercury intrusion porosimetry （MIP）. Interfacial structures between steel fibers and matrix were examined by use of optical microscope. The experimental results show that improvement of pore structures of mortar and fiber-matrix interfacial structure in concrete by combination of steel fiber and MEA may remarkably increase properties of concrete. In comparison with plain concrete, compressive strength and splitting tensile strength of steel fiber reinforced expansive concrete increased by 15.3% and 38.1%, permeability coefficient Kt, penetration depth L and porosity of concrete decreased by 41.1%, 21.3% and 13.1% at 28 days, respectively.

New Pyrometer with Double Y-type Optical Fibers

Abstract: A new pyrometer, which can solve the affection of emissivity change in temperature measuring, has been developed by double Y - type optical fibers. The mathematical model of the new pyrometer is presented and the errors of the new pyrometer are analyzed.

Common Transceiver LIF⁃Lidar Based on Y⁃Type Optical Fiber for Marine Oil Spill Detection

This paper presents a novel laser⁃induced fluorescence(LIF)Lidar system for marine oil spilling detection.A bifurcated Y⁃type optical fiber and an optical collimating lens compose a coaxial configuration transceiver for this LIF⁃Lidar system.This LIF⁃Lidar system was further applied to measure the excitation spectra from floating oil slicks with different thicknesses on top of seawater at different distances.The system presents several advantages such as compact structure,stable optical path,and convenient operation,which offers a wide application prospect in ocean exploration.

Fabrication of 16W all-normal-dispersion mode-locked Yb-doped rod-type fiber laser with large-mode area

A mode-locked ytterbium-doped rod-type fiber laser with 85 ~tm core diameter is developed based on the nonlinear polarization evolution in an all-normal-dispersion ring cavity, in which a uniaxial birefringent plate is used as the spectral filter. Average power up to 16 W is obtained at the repetition rate of 58 MHz, and the pulse duration is compressed to 182 fs with a grating-pair compressor. The output laser pulses show very good beam quality and power stability.

Comparison of Soleus Muscle Fibers in Rats and Rabbits at Different Stages of Postnatal Development

In the present study,the effects of postnatal development on the number and distribution of skeletal muscle fibers of different types in hind leg of rat and rabbit were studied.The soleus muscles of rats aged 2 days,2,4,6,8,and 10 weeks (body weight 10,32,95,190,280,and 320 g),and rabbits aged 2 days,2,4,8,12,16,20,and 24 weeks (body weight 100,220,400,750,1 200,1 600,2 100,and 2 500 g) were stained with succinic dehydrogenase.With an image analysis system,the X-Y coordinates of fibers were used to analyze the growth-related changes.The results of present study showed that three types of fibers were found in the soleus muscles of rat and rabbit,i.e.,type Ⅰ (slow oxidative),ⅡX (fast oxidative),and ⅡA (fast oxidative glycolytic).The type Ⅰ fibers were present throughout the muscle that had a uniform distribution and tended to increase in number with aging.Type ⅡX fibers were scattered throughout the muscle and decreased markedly in number with aging.Type ⅡA fibers were located at the central and deep regions,and showed a little or no change in number and distribution with aging.While be of age,type ⅡA and ⅡX fibers became restricted to the superficial region.No type ⅡB fibers were detected.Type ⅡA fibers had the largest diameter,type Ⅰ intermediate and type ⅡX the smallest.Mean cross-sectional area of each type fibers of rabbits was larger than that of rats.The present results indicate that the number and distribution of muscle fibers of different types in hind limb of rat and rabbit change with the process of postnatal growth.

New Type Color Fiber Application&Trend of Color Spun Product Seminar Open in May

Cope with the global financial crisis,domestic Chinese textile enterprises is facing with more challenges and

Characterization of a Novel RING-Type Ubiquitin E3 Ligase GhRING2 Differentially Expressed in Cotton Fiber

The ubiquitin-proteasome proteolysis pathway is responsible for the degradation of abnormal and short-lived proteins to regulate many important biochemical activities in eukaryotes. By employing affymetrix microarray analysis, we have identified a novel ubiquitin ligase E3 gene GhRING2 that is differentially expressed between two Gossypium hirsutum lines-Texas Marker-1 (TM-1) and Chromosome Substitution Line CS-B25. The CS-B25 line has chromosome 25 from G. barbadense substituted into TM-1. The complete nucleotide sequences of GhRING2 along with its 5’-flanking region were obtained by genomic walking. GhRING2 was highly expressed in elongating fiber, and GUS expression directed by the GhRING2 promoter was found in hypocotyls and young stems of transgenic Arabidopsis plants. Using a yeast two-hybrid assay GhRING2 was found to interact with a PROTODERMAL FACTOR1 (GhPDF1) protein. GhPDF1 was expressed preferentially in immature ovules and fiber initials, and the GhPDF1 gene had been suggested to play a role in cell fate determination and fiber development. Pull down and plasmid swap assays further confirmed the interaction between GhRING2 and GhPDF1. The expression and protein interaction data indicate that GhRING2 may be involved in the turnover of GhPDF1 and participation in the transition from initiation to elongation stages during fiber development. Our data strongly suggest that the ubiquitin-proteasome pathway may regulate cotton fiber growth and development. The nucleotide sequence data of GhRING2 in this article have been submitted to the Gen Bank Nucleotide Sequence Data Bases under the accession number BankIt 1,742,008 SeqKM 108,000.

Effects of dietary protein restriction on muscle fiber characteristics and m TORC1 pathway in the skeletal muscle of growing-finishing pigs

Background： To investigate the effects of dietary crude protein（CP） restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs（62.30 ± 0.88 kg）were allotted to 3 groups and fed with the recommended adequate protein（AP, 16 % CP） diet, moderately restricted protein（MP, 13 % CP） diet and low protein（LP, 10 % CP） diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle（LDM）, psoas major muscle（PMM） and biceps femoris muscle（BFM） were collected and analyzed.Results： Results showed that growing-finishing pigs fed the MP or AP diet improved（P 〈 0.01） the average daily gain and feed： gain ratio compared with those fed the LP diet, and the MP diet tended to increase（P = 0.09） the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated（P 〈 0.05） muscular m RNA expression of all the selected key genes, except that myosin heavy chain（My HC） IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1（m TORC1） pathway was stimulated（P 〈 0.05） in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion： The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.

Neonatal vitamin A injection promotes cattle muscle growth and increases oxidative muscle fibers

Background: Vitamin A and its metabolite,retinoic acid(RA),are important regulators of cell differentiation and organ morphogenesis.Its impact on beef cattle muscle growth remains undefined.Method: Angus steer calves were administrated with 0(control) or 150,000 IU vitamin A(retinyl palmitate in glycerol,i.m.) per calf at birth and 1 month of age.At 2 months of age,a biopsy of the Biceps femoris muscle was obtained to analyze the immediate effects of vitamin A injection on myogenic capacity of muscle cells.The resulting steers were harvested at 14 months of age.Results: Vitamin A administration increased cattle growth at 2 months.At 2 months of age,Vitamin A increased PAX7 positive satellite cells and the expression of myogenic marker genes including PAX7,MYF5,MYOD and MYOG.Muscle derived mononuclear cells were further isolated and induced myogenesis in vitro.More myotubes and a higher degree of myogenesis was observed in vitamin A groups.Consistently,vitamin A increased Latissimus dorsi(LD) muscle fiber size at harvest.In addition,vitamin A increased the ratio of oxidative type I and type IIA fibers and reduced the glycolic type IIX fibers.Furthermore,we found that RA,a key bioactive metabolite of vitamin A,activated PPARGC1 A promoter,which explains the upregulated expression of PPARGC1 A in skeletal muscle.Conclusion: Vitamin A administration to neonatal calves enhanced postnatal muscle growth by promoting myogenesis and increasing satellite cell density,accompanied with a shift to oxidative muscle fibers.

Optical Fiber Grating Sensor for Force Measurement of Anchor Cable

The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable （OFBFMAC）. No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.

Preparation of ferromagnetic binary alloy fine fibers by organic gel-thermal reduction process

Ferromagnetic metal fibers with a high aspect ratio (length/diameter) are attractive for use as high performance electromagnetic interference shielding materials. Ferromagnetic binary alloy fine fibers of iron-nickel, iron-cobalt and cobalt-nickel were prepared by the organic gel-thermal reduction process from the raw materials of critic acid and metal salts. These alloy fibers synthesized were featured with a diameter of about 1 μm and a length as long as 1 m. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of the gel precursors were characterized by FTIR, XRD, TG/DSC and SEM. The gel spinnability largely depends on the molecular structure of metal- carboxylates formed during the gel formation. The gel consisting of linear-type structural molecules shows good spinnability.

Refractometric Fiber Optic Sensor for Detecting Salinity of Water

Salinity is an important property of industrial and natural waters. It is defined as the measure of the mass of dissolved salts in a given mass of solution. High salinity has an impact on people and industries reliant on water. High levels of salt can reduce crop yields, limit the choice of crops that can be grown and, at higher concentrations over long periods, can kill trees and make the land unsuitable for agricultural purposes. Salinity increases the “hardness” of water, which can mean more soap and detergents have to be used or water softeners installed and maintained. This can also cause scaling in pipes and heaters. The experimental determination of the salt content by drying and weighing presents some difficulties due to the loss of some components. The only reliable way to determine the true or absolute salinity of natural water is to make a complete chemical analysis. However, the method is time consuming and cannot yield the precision necessity for accurate work. Thus to determine salinity, one normally used method involves the measurement of a physical property such as conductivity, density or refractive index. The paper reports the refractometric fiber optic sensor for detection of salinity of water. The mathematical model is developed for detection of the refractive index of liquid and simulated in MATLAB. The fiber optic sensor probe is developed to measure the refractive index of the solution containing different amount of salt dissolved in water i.e. different molar concentrations. Experiments are carried out using the developed probe for these solutions. Experimental results are showing good agreement with the simulated results.

亚麻新品种黑亚30号选育报告

黑亚30号是黑龙江省农业科学院经济作物研究所选育的纤维用亚麻新品种;2022年生产试验原茎产量为6705.6 kg/hm^(2),全麻产量为1787.1 kg/hm^(2),分别比黑亚16号增产10.86%和13.00%,全麻率为32.7%,纤维强度282 N;抗旱性强,抗倒伏性强,中抗枯萎病;该品种于2023年12月26日通过中华人民共和国农业农村部非主要农作物品种登记,登记编号为GPD亚麻(胡麻)(2023)230010.

白藜芦醇对肌纤维类型转化的影响及调控机制研究进展

白藜芦醇作为一种来自于葡萄和其他植物的天然多酚化合物,具有抗氧化、抗癌抗肿瘤、保护心血管等作用,一直是多领域的研究热点。骨骼肌主要由肌纤维构成,肌纤维类型和组成是影响肉品质的关键因素。近年来,越来越多研究开始关注白藜芦醇对于骨骼肌纤维类型的转化,同时其具体的调控机制和相关信号通路分子逐渐被确定。本文综合国内外的相关研究报道,总结白藜芦醇对骨骼肌肌纤维类型的影响,综述microRNA、AMPK/SIRT1/PGC-1α、脂联素及FoxO1信号通路在调控肌纤维类型转化方面的作用,以期为今后靶向调控肌纤维类型转化提供理论参考。