Skeletal muscle development, orchestrated by muscle stem cells (MuSCs), is a critical determinant of meat yield and quality in cattle. Transcription factors (TFs) are pivotal regulators of MuSCs fate, yet their specific roles in meat quality remain largely unexplored. In this study, we integrated ATAC-seq and RNA-seq analyses to delineate the chromatin accessibility landscape and transcriptomic dynamics during bovine MuSCs myogenesis, identifying ZBTB18 as a core TF dynamically regulated in this process. ZBTB18 expression was higher in muscles enriched with oxidative myofibers and positively correlated with beef eating quality-related parameters. Functional assays demonstrated that ZBTB18 inhibits MuSCs proliferation while promoting myogenic differentiation, with a specific bias toward oxidative myofiber formation. Mechanistically, we established that ZBTB18 acts as a transcriptional repressor of STAT1. Our findings unveil ZBTB18 as a novel regulator of bovine myogenesis via transcriptional repression of STAT1. Notably, ZBTB18 expression is significantly associated with oxidative myofiber formation and beef eating quality. These findings also provide a strategic target for precision breeding to enhance meat quality in cattle.

Super-enhancers (SEs) are critical epigenetic regulators of tissue regeneration, yet their interplay with cellular biomechanics during myogenic differentiation remains unexplored. Here, the TPM1 locus, encoding a core actin-stabilizing protein essential for skeletal muscle regeneration, harbors an evolutionarily conserved SE (TPM1_SE) that may bridge epigenetic control and mechanotransduction. In vitro, TPM1_SE deletion impaired myogenic differentiation and diminished expression of both TPM1 and its circular RNA (circRNA) isoform, CircTPM1. Conditional deletion of TPM1_SE significantly reduce muscle mass and delayed regenerative progression. Mechanistically, TPM1_SE drives expression of linear TPM1 mRNA (mice) and CircTPM1 (bovine) via TEAD4-mediated chromatin looping, coordinating cytoskeletal reorganization during myotube formation. These effects are mediated via activation of the canonical PI3K/AKT signaling pathway through interaction with NKX2.2-a pathway mechanosensitive to cellular tension. Loss of TPM1_SE disrupted NKX2.2-PI3K/AKT signaling. Crucially, CircTPM1 directly bound MYH10, enhancing MYL3-dependent actomyosin assembly, which potentiates cytoskeletal reorganization during myotube formation. Collectively, this findings establish TPM1_SE as an evolutionarily conserved hub integrating epigenetic regulation and biomechanical output. While the murine model underscores its therapeutic potential in muscle regenerative medicine, the bovine CircTPM1-mediated mechanism highlights TPM1_SE as a promising target for genetic improvement of meat quality in livestock.

Skeletal muscle, the primary meat-producing tissue in bovines, is regulated by a complex transcriptional network during development. The role of Thrombospondin 3 (THBS3) and its associated super-enhancer (SE) in this process remains largely unknown. Here, by integrating multi-omics data, we identified THBS3 as a novel core regulator of myogenesis, orchestrated by a cognate super-enhancer (THBS3-SE). Functional assays demonstrated that THBS3 knockdown significantly promoted the proliferation and myogenic differentiation of bovine muscle stem cells (MuSCs) and accelerated their commitment to a fast-twitch fiber fate. Transcriptomic analysis linked THBS3 function to key signaling pathways controlling muscle growth, especially the mechanistic target of rapamycin (mTOR) signaling pathway. Mechanistically, we found that distal enhancers within the THBS3-SE loop to the THBS3 promoter drive its transcription, and CRISPR-based interference of these enhancers recapitulated the pro-myogenic effects of THBS3 knockdown. Collectively, our findings unveiled a THBS3-SE-mediated regulatory axis that critically governed bovine MuSCs’ fate. Targeting this axis may offer a novel strategy for improving beef production efficiency.

Hypoxia in the mammary gland epithelial cells of milk buffalo (BMECs) can affect milk yield and composition, and it can even cause metabolic diseases. Nitidine chloride (NC) is a natural alkaloid with antioxidant properties that can scavenge excessive reactive oxygen species (ROS). However, the effect of NC on the hypoxic injury of BMECs and its molecular mechanisms are still unknown. Here, an immunofluorescence assay, transmission electron microscopy (TEM), and flow cytometry, combined with untargeted metabolomics, were used to investigate the protective effect of NC on hypoxic stress injury in BMECs. It was found that NC can significantly reduce cell activity (p < 0.05) and inhibit cellular oxidative stress (p < 0.05) and cell apoptosis (p < 0.05). A significant decrease in mitophagy mediated by the PINK1-Parkin pathway was observed after NC pretreatment (p < 0.05). In addition, a metabolic pathway enrichment analysis demonstrated that the mechanisms of NC against hypoxic stress may be related to the downregulation of pathways involving aminoacyl tRNA biosynthesis; arginine and proline metabolism; glycine, serine, and threonine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; and phenylalanine metabolism. Thus, NC has a protective effect on hypoxic mitochondria, and it can regulate amino acid metabolism in response to hypoxic stress. The present study provides a reference for the application of nitidine chloride to regulate the mammary lactation function of milk buffalo.

With the rapid development of intensive animal husbandry in the livestock industry, large quantities of manure waste containing phytate phosphorus are being generated. Phytase can effectively solve the problem of high phosphorus pollution in the feces of monogastric animals. Enviropig, which produces phytase in the salivary glands and secretes the enzyme in the saliva, were first generated in 1999. However, phytase is easily inactivated during digestion. To address this problem, cleavage-resistant phytase transgenic pigs were generated using handmade cloning in this study. Transgene construction was improved and three cell lines carrying Cafp were obtained. In total, 810 blastocysts were generated and 712 good-quality were transferred into six recipients. Fourteen piglets were born, of which six survived after weaning. Polymerase chain reaction and sequencing results showed that seven (three live and four dead) of the fourteen piglets carried Cafp. Phytase activity in the saliva of the six live cloned pigs was tested at four months of age, and only one pig had 0.155 FTU/mL enzyme activity. The other five pigs may not have been activated in the transgenic parotid gland. Among all the transgenic pigs, the highest phosphorus digestion rate was 59.2% of intake, representing a 25.4% decrease in fecal emission compared to the average of controls. Immunohistochemical results on the three Cafp-positive pigs that died after six months of age showed that the transgene was only expressed in parotid glands, confirming tissue-specific gene expression. In conclusion, cleavage-resistant phytase transgenic pigs were successfully produced through handmade cloning. The cloned pigs offer a unique biological approach to managing phosphorus nutrition and environmental pollution in animal husbandry.

MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate several pathway intermediates and affect the skeletal muscle development in mice, pigs, sheep, and cattle. However, to date, only a small number of miRNAs have been reported in the muscle development of goats. In this report, the longissimus dorsi transcripts of one- and ten-month-old goats were analyzed by sequencing RNAs and miRNAs. The results showed that the ten-month-old Longlin goats had 327 up- and 419 down-regulated differentially expressed genes (DEGs) compared with the one-month-old. In addition, 20 co-up-regulated and 55 co-down-regulated miRNAs involved in the muscle fiber hypertrophy of goats were identified in ten-month-old Longlin and Nubian goats compared with one-month-old. Five miRNA-mRNA pairs (chi-let-7b-3p-MIRLET7A, chi-miR193b-3p-MMP14, chi-miR-355-5p-DGAT2, novel_128-LOC102178119, novel_140-SOD3) involved in the goat skeletal muscle development were identified by miRNA-mRNA negative correlation network analysis. Our results provided new insight into the functional roles of goat muscle-associated miRNAs, allowing a deeper understanding of the transformation of miRNA roles during mammalian muscle development.

本试验旨在探讨日粮中不同水平蛋白质和能量对西门塔尔杂交牛生产性能和经济效益的影响,为生产高质量牛肉、增加养殖经济效益提供依据.试验选取体重、出生日期相近的健康西门塔尔杂交育肥牛(约220 kg)30头,随机分为对照组、试验Ⅰ组和试验Ⅱ组,每组各10头,分别饲喂含不同水平蛋白质和能量的日粮.结果表明:试验Ⅰ组在高能量、高蛋白的水平下净增重为1.93 kg/(头·d),净利润率可达19.5％,比对照组净利润率高13.1％;而试验Ⅱ组在蛋白含量一定、能量水平较高的条件下净增重为1.77 kg/(头·d),净利润率为16.4％,比对照组净利润率高10％.试验组日增重水平显著高于对照组(P<0.05).由此可见,适当地提高全混合颗粒日粮的养分含量,可以明显提升220～350 kg西门塔尔杂交育肥牛的增重效果,使得经济效益最大化.

广西贫困人口绝大部分分布在石漠化严重的大石山区,石漠化引起的生态恶化加剧了贫困程度,阻碍区域经济的发展.该研究探索广西石漠化山区肉牛养殖产业盈利运营模式,协调石漠化治理与肉牛产业发展之间的关系,加快实现脱贫攻坚奔小康和产业兴旺乡村振兴目标的步伐,提升人民群众生活水平和生活质量,为石漠化极度贫困山区肉牛产业持续发展壮大提供参考和借鉴.

本试验旨在研究2种不同蛋白水平日粮对湖羊生长性能、肉品质及血常规的影响.选择健康的5月龄公湖羊20只,随机分为2组,每组10只;对照组湖羊初始体重为(27.23±1.87)kg,基础日粮的粗蛋白水平为8.63％;高蛋白组湖羊初始体重为(27.21±1.79)kg,设计日粮的粗蛋白水平为16.35％;预试期7 d、正试期57 d.结果表明:高蛋白组湖羊试验结束时末重、平均日增重均显著高于对照组(P<0.05),料重比显著低于对照组(P<0.05);2组湖羊的净肉率、骨率和骨肉比差异不显著(P>0.05),高蛋白组湖羊的宰前活重、胴体重、屠宰率和净肉重均显著高于对照组(P<0.05);2组湖羊的肉品质相关指标无差异,其血常规指标均处于正常范围.由此可见,饲喂高蛋白水平日粮能显著提高育肥期湖羊生长性能,且不影响湖羊的健康和肉品质.

随着社会的发展和人民生活水平的提高,对肉类的需求逐步由传统的猪肉、鸡肉和鱼肉向牛肉等高档肉类消费转变.近年来,肉牛肉羊养殖产业市场行情稳中向好,大力的政策扶持使得大量的社会资本进入到牛羊养殖领域,各地牛羊草食动物养殖蓬勃发展,产业迅速扩大发展也逐渐暴露了制约产业发展的问题,牛羊养殖企业难赚钱、不赚钱、亏本经营的现象愈发普遍.本文调查和跟踪了桂林市牛羊产业发展状况,阐述了广西牛羊产业发展存在的共性问题,总结了养殖盈利运营的一些好的经验做法,为桂林以及广西牛羊产业高质量发展提供参考.

近年来,牛羊产业是广西农村巩固脱贫攻坚、助力乡村振兴的重要产业之一,是农业经济的重要组成部分.本文主要针对广西桂南地区牛羊养殖现状、产业发展区域优势、技术瓶颈、发展方向、解决方案及建议等发展态势进行分析,为助力乡村振兴、推动桂南地区牛羊产业经济带高质量发展提供参考依据.

The proliferation and myogenic differentiation of muscle stem cells (MuSCs) are important factors affecting muscle development and beef quality. There is increasing evidence that circRNAs can regulate myogenesis. We found a novel circRNA, named circRRAS2 that is significantly upregulated in the differentiation phase of bovine MuSCs. Here, we aimed to determine its roles in the proliferation and myogenic differentiation of these cells. The results showed that circRRAS2 was expressed in several bovine tissues. CircRRAS2 inhibited MuSCs proliferation and promoted myoblast differentiation. In addition, chromatin isolation by using RNA purification and mass spectrometry in differentiated muscle cells identified 52 RNA-binding proteins that could potentially bind to circRRAS2, in order to regulate their differentiation. The results suggest that circRRAS2 could be a specific regulator of myogenesis in bovine muscle.HighlightsCircRRAS2 expression is higher in DM cells than in GM cells.CircRRAS2 could significantly inhibit the proliferation and apoptosis of bovine MuSCs.CircRRAS2 promotes the differentiation of bovine MuSCs into myotubes.CircRRAS2 may exert regulatory effects through multiple RNA binding proteins.

【Objective】At present, studies have proved that circRNA plays important roles in the development of bovine muscle, but its molecular regulation mechanism remain elusive. Screening circRNAs related to bovine muscle development can lay a foundation for further elucidating the molecular mechanism of bovine muscle development.【Method】In this study, RNA-seq sequencing results of proliferating (GM) and myogenic differentiation (DM) yellow bovine muscle stem cells (MuSCs) analyzed in the previous stage were used to screen for significantly differentially expressed circRNA, circCEP85L. Tissue samples of heart, liver, spleen, lung, kidney, muscle, intestine and stomach were collected aseptically from fresh yellow fetal calves, and yellow muscle stem cells were isolated and cultured and induced into myogenic differentiation. GM and DM cells cultured in vitro from yellow calves were collected, RNA was extracted and reverse transcribed into cDNA, respectively. Quantitative real time PCR (qRT-PCR) was used to detect the expression of circCEP85L in different tissues and different cell states. Meanwhile, specific primers were designed to amplify the full length of circCEP85L, and the overexpression vector p-circCEP85L was constructed. The plasmid was transfected into MuSCs and overexpressed circCEP85L cell samples were collected. Using overexpression plasmid pCD5-ciR cell samples as control, qRT-PCR, flow cytometry, Western Blot and immunofluorescence were used to detect the effects of overexpression of circCEP85L on proliferation, apoptosis and myogenic differentiation of yellow bovine MuSCs.【Result】The electrophoresis of PCR product proved the existence of circCEP85L. CircCEP85L was expressed in various tissues, and the expression level in DM stage was significantly higher than that in GM stage (P<0.001). To further investigate the effect on circCEP85L scallion MuSCs. The overexpression vector p-circCEP85L was transfected with the control vector pCD5-ciR in vitro cultured yellow bovine MuSCs and the EdU results showed that overexpression of circCEP85L significantly reduced the proportion of EdU positive cells (P<0.001) after continuing the culture for 24 h. Flow cycle analysis showed that overexpression of circCEP85L increased the proportion of cells in G0/G1 phase and significantly decreased the proportion of cells in S phase (P<0.001). Flow cytometry showed that overexpression of circCEP85L significantly inhibited the apoptosis rate of MuSCs (P<0.05). qRT-PCR and western blot were used to detect the expression of proliferation and apoptosis-related genes in MuSCs, respectively. The results showed that overexpression of circCEP85L significantly reduced the mRNA expression levels of proliferation and apoptosis-related genes in bovine MuSCs (P<0.001), and the expression of apoptotic protein BAX was also significantly reduced (P<0.01). In addition, in order to detect the effect of circCEP85L overexpression on myogenic differentiation of cattle MuSCs, the differentiation medium was replaced 24 hours after transfection to induce cell differentiation. Western blot and immunofluorescence results showed that overexpression of circCEP85L significantly promoted the expression level of differentiation marker gene MyH6 (P<0.001), and the number and size of myotubes formed by cell fusion were significantly higher than those of the control group.【Conclusion】The results of this study indicate that circCEP85L affects the growth and development process of skeletal muscle in cattle by inhibiting the proliferation and apoptosis of MuSCs and promoting myogenic differentiation of cells, which is expected to be a key circRNA for subsequent mechanistic studies to regulate the growth and development process of skeletal muscle in cattle.

本试验旨在研究甘肃不同地区小麦秸秆纤维水平的差异.按不同地区分为5 组.采用范氏(Van Soest)法测定小麦秸秆中的NDF与ADF.结果表明,凉州、民乐、古浪三个县的NDF含量显著高于甘州和山丹两县(P<0.05),甘州高于山丹(P<0.05);古浪县小麦秸秆中的ADF含量显著高于凉州、民乐、甘州、山丹四个县的(P<0.05),凉州、民乐县的ADF含量又显著高于甘州、山丹这两县(P<0.05),同时甘州县小麦的ADF含量显著高于山丹县(P<0.05).这为今后不同地区小麦秸秆饲用采购提供一定的理论依据.

为了建立检测非洲猪瘟病毒(ASFV)的间接ELISA方法,试验基于p72/p32基因序列,构建了重组质粒pCold-p72/p32,将其转化至大肠杆菌BL21(DE3)感受态细胞中,利用IPTG诱导获得相应的重组蛋白,通过SDS-PAGE分析重组蛋白的表达形式,利用Ni2+柱亲和层析法纯化p72/p32重组蛋白,并以此为包被抗原建立2种快速检测ASFV的间接ELISA方法,并对方法的临界值、有无交叉反应、重复性及敏感性进行了检测,并对来自不同猪场的临床样本进行验证性检测.结果表明:试验成功构建了重组质粒pCold-p72/p32,2种重组蛋白均能与ASFV阳性血清反应;p32以可溶性蛋白和包涵体蛋白形式表达,p72以包涵体蛋白形式表达.基于p32重组蛋白所建立的间接ELISA方法的临界值为0.543,基于p72重组蛋白所建立的间接ELISA方法的临界值为0.612;批内、批间重复性试验的变异系数均小于10％;与猪瘟病毒(CSFV)、猪圆环病毒2型(PCV-2)、猪伪狂犬病毒(PRV)、猪繁殖与呼吸综合征病毒(PRRSV)等常见病原的阳性血清无交叉反应;与商品化的非洲猪瘟抗体试剂盒检测结果的符合率分别为95.1％和91.3％.说明试验建立的2种间接ELISA方法均具有良好的特异性、敏感性和重复性.通过比较,可以初步认为以p32重组蛋白为包被抗原建立的间接ELISA方法检测效果更好,可以用于猪血清样本中ASFV抗体的检测.

本实验旨在体外构建猪颗粒细胞黄体化模型,为由母猪黄体发育引起的繁殖障碍预防和治疗提供参考.分别采用自然培养法、人绒毛膜促性腺激素(HCG)和胰岛素对猪颗粒细胞进行黄体化处理,通过CCK-8、流式细胞仪、ELISA和QRT-PCR技术检测细胞活力、细胞凋亡率、孕激素含量以及黄体化相关基因的相对表达量,对处理后的黄体化效果进行评估.结果显示:使用5 IU/mL HCG培养猪颗粒细胞2 d和2 μg/mL胰岛素培养猪颗粒细胞3 d均可使猪颗粒细胞发生黄体化.在使用2 μg/mL胰岛素培养猪颗粒细胞3 d引起黄体化的过程中,其细胞活力和增殖情况良好,孕酮含量显著上升,黄体化相关基因3β-HSD、STAR表达显著下降,CYP11A1表达显著上升,是一种较好的猪颗粒细胞黄体化诱导方法.本研究初步建立了猪颗粒细胞体外黄体化细胞模型,为后续开展颗粒细胞黄体化的机理及其功能研究提供理论参考.

Myogenesis is an essential process that can affect the yield and quality of beef. Transcriptional studies have shown that histone deacetylase 11 (HDAC11) was differentially expressed in muscle tissues of 6 and 18 month old Longlin cattle, but its role in the regulation of myogenesis remains unclear. This study aimed to determine the role of HDAC11 in the proliferation and differentiation of bovine muscle stem cells (MuSCs). HDAC11 promoted MuSC proliferation by activating Notch signaling and inhibited myoblast differentiation by reducing MyoD1 transcription. In addition, overexpression of HDAC11 inhibited the repair regeneration process of muscle in mice. HDAC11 was found to be a novel key target for the control of myogenesis, and this is a theoretical basis for the development of HDAC11-specific modulators as a new strategy to regulate myogenesis.

试验旨在探究罗汉果甜苷对育肥后期湖羊生长性能、血液生理生化指标、屠宰性能及肉品质的影响.试验选取体重相近[(43.77±0.39)kg]的育肥后期湖羊40只,随机分为对照组和试验组,每组20只.对照组饲喂基础饲粮,试验组在基础饲粮中添加600 mg/kg的罗汉果甜苷,试验期为56 d.结果表明:与对照组相比,试验组湖羊的末重和平均日增重显著提高(P<0.05),料重比显著降低(P<0.05);净肉率显著提高(P<0.05),在一定程度上提高了试验组湖羊的胴体重和净肉重,但是差异不显著(P>0.05);同时,显著降低了试验组湖羊的剪切力(P<0.05),提高了肌内脂肪含量(P<0.05).综上所述,在日粮中添加600 mg/kg的罗汉果甜苷能显著提高湖羊的日增重、降低料重比、提高肌肉嫩度和肌内脂肪含量,对肉质起到了一定的改善作用.

[目的]明确修饰基因组通过穿膜肽载体转染精子的可行性及穿膜肽载体对精子和受精卵的影响,为实现安全有效地大批量制备猪转基因胚胎提供技术支撑.[方法]以水牛Sohlh2基因为目的基因,通过细胞穿膜肽(C105y、MPG和TAT)和慢病毒介导转染猪精子后,采用激光共聚焦扫描显微镜观察转染精子形态特征的变化,利用精子图像分析仪(CASA)检测精子活率、平均曲线运动速度(VCL)、平均直线运动速度(VSL)和前向性(STR)等指标,运用精子顶体染色试剂盒测定猪精子顶体反应,并通过体外受精进一步验证不同载体转染制备生产转Sohlh基因猪胚胎的效果.[结果]转染后的猪精子顶体结构完整,细胞膜未见破裂;不同细胞穿膜肽(C105y、MPG和TAT)的猪精子转染阳性率分别为56.74％、50.44％和43.58％,低于慢病毒的转染阳性率(61.48％),但差异不显著(P>0.05,下同).经穿膜肽C105y转染24 h,猪精子活率(70.09％)、平均直线运动速度(35.36μm/s)、平均曲线运动速度(42.20μm/s)、前向性(1.03μm/s)与对照组相比差异均不显著;而经穿膜肽MPG和TAT及慢病毒转染后,猪精子的各项指标均呈一定程度的下降趋势.细胞穿膜肽转染猪精子的自发顶体反应率与对照组相比无显著差异,慢病毒转染则呈显著的上升趋势(P<0.05,下同);在诱发顶体反应率方面,慢病毒转染猪精子的诱发顶体反应率较对照组呈显著下降趋势,而不同细胞穿膜肽转染对猪精子诱发顶体反应率也无显著影响.慢病毒和穿膜肽C105y转染猪精子经体外受精获得的受精卵继续培养24 h后其卵裂率为64.82％和65.91％,与对照组受精卵的卵裂率(64.52％)差异不显著;穿膜肽C105y转染组的囊胚率(15.82％)与对照组间无显著差异,而慢病毒转染组的囊胚率(9.11％)显著低于对照组;在转基因胚胎阳性率方面,穿膜肽C105y转染组显著低于慢病毒转染组(8.54％vs 10.38％).[结论]穿膜肽C105y对猪精子的受精能力及转基因猪胚胎发育影响小,且毒害作用不明显,是一个能高效转导外源基因的安全载体.

Background The growth and development of muscle stem cells (MuSCs) are significant events known to affect muscle plasticity, disease, meat production, and meat quality, which involves the types and functions of mRNA and non-coding RNA. Here, MuSCs were cultured from Guangxi fetal cattle. RNA sequencing was used to analyze the RNA expression of mRNA and non-coding RNAs during the cell proliferation and differentiation phases. Results Two thousand one hundred forty-eight mRNAs and 888 non-coding RNAs were differentially expressed between cell proliferation and differentiation phases, including 113 miRNAs, 662 lncRNAs, and 113 circRNAs. RT-qPCR verified the differential expression levels of mRNAs and non-coding RNAs, and the differentially expressed circUBE2Q2 was subsequently characterized. Expression profile analysis revealed that circUBE2Q2 was abundant in muscle tissues and intramuscular fat. The expression of cricUBE2Q2 was also significantly upregulated during MuSCs myogenic differentiation and SVFs adipogenic differentiation and decreased with age in cattle muscle tissue. Finally, the molecular mechanism of circUBE2Q2 regulating MuSCs function that affects skeletal muscle development was investigated. The results showed that circUBE2Q2 could serve as a sponge for miR-133a, significantly promoting differentiation and apoptosis of cultured MuSCs, and inhibiting proliferation of MuSCs. Conclusions CircUBE2Q2 is associated with muscle growth and development and induces MuSCs myogenic differentiation through sponging miR-133a. This study will provide new clues for the mechanisms by which mRNAs and non-coding RNAs regulate skeletal muscle growth and development, affecting muscle quality and diseases.