Metabolomics reveals the reasons for the occurrence of Pendulous-comb related to egg production performance.

The chicken comb is an essential secondary sexual characteristic to measure sexual maturity and is closely related to reproductive performance. Pendulous comb (PC) and upright comb (UC) are 2 common comb phenotypes in hens, which have been highly associated with egg production performance. However, the reasons for the formation of PC remain undetermined. In this study, we first characterized the PC and UC chicken at start (at 175 d age), peak (at 217 d age), and postlaying (at 300 d age) and found that PC and UC could transform for each other. Furthermore, we suggested that PC chicken demonstrated better egg production performance than UC chicken, especially characterizing comb type in the start-laying period. Moreover, we performed histological evaluation of PC and UC tissue, which suggested that the low density of collagen fibers and acid mucopolysaccharides might lead to the formation of PC. To further explore the possible reasons for PC formation, we performed an untargeted metabolomic analysis of serum between PC and UC chicken in the start, peak, and postlaying periods. The enrichment analysis of period-unique differentially expressed metabolites (DEMs) between PC and UC showed that the different metabolic pathways and nutritional levels might contribute to the formation of PC in the different laying periods. Our research provided critical insights into the phenotypic diversity of chicken comb, establishing a foundation for early selection of chicken egg production performance.

Comprehensive analysis of differentially expressed mRNA profiles in chicken jejunum and cecum following Eimeria maxima infection.

Coccidiosis, a protozoan disease that substantially impacts poultry production, is characterized by an intracellular parasite. The study utilized 48 one-day-old Horro chickens, randomly divided into the infected (I) and control (C) groups. The challenge group of chickens were administered Eimeria maxima oocysts via oral gavage at 21-days-old, and each chicken received 2 mL containing 7×104 sporulated oocysts. The total RNAs of chicken jejunum and cecum tissues were isolated from three samples, each from I and C groups. Our study aimed to understand the host immune-parasite interactions and compare immune response mRNA profiles in chicken jejunum and cecum tissues at 4 and 7 days postinfection with Eimeria maxima. The results showed that 823 up- and 737 down-regulated differentially expressed mRNAs (DEmRNAs) in jejunum at 4 d infection and control (J4I vs. J4C), and 710 up- and 368 down-regulated DEmRNAs in jejunum at 7 days infection and control (J7I vs. J7C) were identified. In addition, DEmRNAs in cecum tissue, 1424 up- and 1930 down-regulated genes in cecum at 4 days infection and control (C4I vs. C4C), and 77 up- and 191 down-regulated genes in cecum at 7 days infection and control (C7I vs. C7C) were detected. The crucial DEmRNAs, including SLC7A5, IL1R2, GLDC, ITGB6, ADAMTS4, IL1RAP, TNFRSF11B, IMPG2, WNT9A, and FOXF1, played pivotal roles in the immune response during Eimeria maxima infection of chicken jejunum. In addition, the potential detection of FSTL3, RBP7, CCL20, DPP4, PRKG2, TFPI2, and CDKN1A in the cecum during the host immune response against Eimeria maxima infection is particularly noteworthy. Furthermore, our functional enrichment analysis revealed the primary involvement of DEmRNAs in small molecule metabolic process, immune response function, inflammatory response, and toll-like receptor 10 signaling pathway in the jejunum at 4 and 7 days postinfection. Similarly, in the cecum, DEmRNAs at 4 and 7 days postinfection were enriched in processes related to oxidative stress response and immune responses. Our findings provide new insights and contribute significantly to the field of poultry production and parasitology.

A dry chemistry-based self-enhanced electrochemiluminescence lateral flow immunoassay sensor for accurate sample-to-answer detection of luteinizing hormone.

BACKGROUND: Colorimetric lateral flow immunoassay (LFIA) is a widely used point-of-care testing (POCT) technology, while it has entered a bottleneck period because of low detection sensitivity, expensive preparation materials, and incapable quantitative detection. Therefore, it is necessary to develop a novel POCT method that is ultrasensitive, simple, portable, and capable of accurately detecting biomarkers in biofluids daily, particularly for pregnancy preparation and early screening of diseases. RESULT: In this work, a novel dry chemistry-based self-enhanced electrochemiluminescence (DC-SE-ECL) LFIA sensor is introduced for accurate POCT of luteinizing hormone (LH). The proposed DC-SE-ECL immunosensor significantly improves the detection sensitivity through the Poly-l-Lysine (PLL)-based SE-ECL probe and cathode modification of closed bipolar electrode (C-BPE). Additionally, a new type of C-BPE configuration is designed for easily performing the LFIA. And, two standalone absorbent pads are symmetrically arranged below the reporting channel of the electrode pad to decease useless residues on the detection pad, which further improves the detection performance. Under optimized conditions, the proposed LFIA sensor has a low limit of detection (9.274 µIU mL-1) and a wide linear dynamic range (0.01-100 mIU mL-1), together with good selectivity, repeatability and storage stability. SIGNIFICANCE: These results indicate that the proposed DC-SE-ECL method has the potential as a new tool for detecting biomarkers in clinical samples.

Assessment of selective breeding effects and selection signatures in Qingyuan partridge chicken and its strains.

Qingyuan partridge chicken (QYM) is a highly regarded native breed in China, highly esteemed for its exceptional breeding characteristics. However, the investigation into the selection signatures and its strains remains largely unexplored. In this study, blood sampling, DNA extracting, and high-depth resequencing were performed in 27 QYMs. Integrating the genomic data of 14 chicken (70 individuals) breeds from other researches, to analyze the genetic structure, selection signatures, and effects of selective breeding within QYM and its 3 strains (QYMA, QYMB, and QYMC). Population structure analysis revealed an independent QYM cluster, which exhibited distinct from other breeds, with each of its 3 strains displaying distinct clustering patterns. Linkage disequilibrium analysis highlighted QYMB's notably slower decay rate, potentially influenced by selection pressure from various production indicators. Examination of selection signatures uncovered genes and genetic mechanisms associated with genomic changes resulting from extensive selective breeding within the QYM and its strains. Intriguingly, diacylglycerol kinase beta (DGKB) and catenin alpha 2 (CTNNA2) were identified as commonly selected genes across the 3 QYM strains, linked to energy metabolism, muscle development, and fat metabolism. Our research validates the substantial impact of selective breeding on QYM and its strains, concurrently identifying genomic regions and signaling pathways associated with their distinctive characters. This research also establishes a fundamental framework for advancing yellow-feathered broiler breeding strategies.

MYH1G-AS is a chromatin-associated lncRNA that regulates skeletal muscle development in chicken.

BACKGROUND: Skeletal muscle development is pivotal for animal growth and health. Recently, long noncoding RNAs (lncRNAs) were found to interact with chromatin through diverse roles. However, little is known about how lncRNAs act as chromatin-associated RNAs to regulate skeletal muscle development. Here, we aim to investigate the regulation of chromatin-associated RNA (MYH1G-AS) during skeletal muscle development. METHODS: We provided comprehensive insight into the RNA profile and chromatin accessibility of different myofibers, combining RNA sequencing (RNA-seq) with an assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq). The dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to analyze the transcriptional regulation mechanism of MYH1G-AS. ALKBH5-mediated MYH1G-AS N6-methyladenosine (m6A) demethylation was assessed by a single-base elongation and ligation-based qPCR amplification method (SELECT) assay. Functions of MYH1G-AS were investigated through a primary myoblast and lentivirus/cholesterol-modified antisense oligonucleotide (ASO)-mediated animal model. To validate the interaction of MYH1G-AS with fibroblast growth factor 18 (FGF18) protein, RNA pull down and an RNA immunoprecipitation (RIP) assay were performed. Specifically, the interaction between FGF18 and SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 5 (SMARCA5) protein was analyzed by coimmunoprecipitation (Co-IP) and a yeast two-hybrid assay. RESULTS: A total of 45 differentially expressed (DE) lncRNAs, with DE ATAC-seq peaks in their promoter region, were classified as open chromatin-associated lncRNAs. A skeletal muscle-specific lncRNA (MSTRG.15576.9; MYH1G-AS), which is one of the open chromatin-associated lncRNA, was identified. MYH1G-AS transcription is coordinately regulated by transcription factors (TF) SMAD3 and SP2. Moreover, SP2 represses ALKBH5 transcription to weaken ALKBH5-mediated m6A demethylation of MYH1G-AS, thus destroying MYH1G-AS RNA stability. MYH1G-AS accelerates myoblast proliferation but restrains myoblast differentiation. Moreover, MYH1G-AS drives a switch from slow-twitch to fast-twitch fibers and causes muscle atrophy. Mechanistically, MYH1G-AS inhibits FGF18 protein stabilization to reduce the interaction of FGF18 to SMARCA5, thus repressing chromatin accessibility of the SMAD4 promoter to activate the SMAD4-dependent pathway. CONCLUSIONS: Our results reveal a new pattern of the regulation of lncRNA expression at diverse levels and help expound the regulation of m6A methylation on chromatin status.

LncEDCH1 g.1703613 T>C regulates chicken carcass traits by targeting miR-196-2-3p.

Single nucleotide polymorphisms (SNPs) are valuable genetic markers that can provide insights into the genetic diversity and variation within chicken populations. In poultry breeding, SNP analysis is widely utilized to accelerate the selection of desirable traits, improving the efficiency and effectiveness of chicken breeding programs. In our previous research, we identified an association between LncEDCH1 and muscle development. To further investigate its specific mechanism, we conducted SNP detection and performed genotyping, linkage disequilibrium, and haplotype analysis. Our research findings indicate that 16 SNPs in the LncEDCH1. Among these SNPs, g.1703497 C>T and g.1704262 C>T were significantly associated with breast muscle weight percentage, g.1703497 C>T and g.1703613 T>C were significantly associated with leg weight percentage, and g.1703497 C>T, g.1703589 T>C, g.1703613 T>C, g.1703636 C>A, g.1703768 T>C, g.1704079 C>T, g.1704250 T>C, g.1704253 G>A were significantly associated with skin yellowness. Two haplotype blocks composed of 6 SNPs that were significantly associated with wing skin yellowness, breast skin yellowness, full-bore weight, and carcass weight percentage. Furthermore, through dual-luciferase reporter assays, biotin-coupled miRNA pull-down assays, 5-ethynyl-2'-deoxyuridine (EDU) assays, immunofluorescence, and quantitative real-time polymerase chain reaction (qPCR), it has been confirmed that miR-196-2-3p inhibits the expression of LncEDCH1 directly by binding to LncEDCH1 g.1703613T>C, thereby achieving indirect regulation of muscle development. These findings provide valuable molecular markers for chicken molecular breeding and broaden our understanding of the regulatory mechanisms.

Encapsulation of lycopene into electrospun nanofibers from whey protein isolate-Tricholoma lobayense polysaccharide complex stabilized emulsions: Structural characterization, storage stability, in vitro release, and cellular evaluation.

In this study, lycopene-loaded nanofibers were successfully fabricated by electrospinning of oil-in-water (O/W) emulsions stabilized by whey protein isolate-polysaccharide TLH-3 (WPI-TLH-3) complexes. The lycopene encapsulated in the emulsion-based nanofibers exhibited enhanced photostability and thermostability, and achieved improved targeted small intestine-specific release. The release of lycopene from the nanofibers followed Fickian diffusion mechanism in simulated gastric fluid (SGF) and first-order model in simulated intestinal fluid (SIF) with the enhanced release rates. The bioaccessibility and cellular uptake efficiency of lycopene in micelles by Caco-2 cells after in vitro digestion were significantly improved. The intestinal membrane permeability and transmembrane transport efficiency of lycopene in micelles across Caco-2 cells monolayer were greatly elevated, thus promoting the effective absorption and intracellular antioxidant activity of lycopene. This work opens a potential approach for electrospinning of emulsions stabilized by protein-polysaccharide complexes as a novel delivery system for liposoluble nutrients with enhanced bioavailability in functional food industries.

Hyperspectral full polarization imaging system based on spatial modulation.

The hyperspectral full polarization imaging system (HFPIS) based on spatial modulation and liquid crystal tunable filter (LCTF) can modulate the polarization information of the target into the interferogram by means of interference imaging. It has the advantage of rapid imaging of the hyperspectral full polarization information from the target, and has good real time imaging and practicality. Through the spectroscopic imaging mode of a Savart prism, the corresponding interference optical path and imaging system are designed, including a beam expander, spatial modulator, LCTF, focusing system, and imaging sensor. This system can extract the different information from the target and demodulate it so as to obtain the hyperspectral polarization image. The experiment shows that the HFPIS can reveal the texture, contour, and other details of the target in the fog, and has obvious advantages over the traditional intensity imaging methods.

LncRNA-TBP mediates TATA-binding protein recruitment to regulate myogenesis and induce slow-twitch myofibers.

BACKGROUND: Skeletal muscle is comprised of heterogeneous myofibers that differ in their physiological and metabolic parameters. Of these, slow-twitch (type I; oxidative) myofibers have more myoglobin, more mitochondria, and higher activity of oxidative metabolic enzymes compared to fast-twitch (type II; glycolytic) myofibers. METHODS: In our previous study, we found a novel LncRNA-TBP (for "LncRNA directly binds TBP transcription factor") is specifically enriched in the soleus (which has a higher proportion of slow myofibers). The primary myoblast cells and animal model were used to assess the biological function of the LncRNA-TBP in vitro or in vivo. Meanwhile, we performed a RNA immunoprecipitation (RIP) and pull-down analysis to validate this interaction between LncRNA-TBP and TBP. RESULTS: Functional studies demonstrated that LncRNA-TBP inhibits myoblast proliferation but promotes myogenic differentiation in vitro. In vivo, LncRNA-TBP reduces fat deposition, activating slow-twitch muscle phenotype and inducing muscle hypertrophy. Mechanistically, LncRNA-TBP acts as a regulatory RNA that directly interacts with TBP protein to regulate the transcriptional activity of TBP-target genes (such as KLF4, GPI, TNNI2, and CDKN1A). CONCLUSION: Our findings present a novel model about the regulation of LncRNA-TBP, which can regulate the transcriptional activity of TBP-target genes by recruiting TBP protein, thus modulating myogenesis progression and inducing slow-twitch fibers. Video Abstract.

Polymorphisms of CRELD1 and DNAJC30 and their relationship with chicken carcass traits.

Carcass traits play important roles in the broiler industry and single nucleotide polymorphism (SNP) can be efficient molecular markers for marker-assisted breeding of chicken carcass traits. Based on our previous RNA-seq data (accession number GSE58755), cysteine rich with epidermal growth factor like domains 1 (CRELD1) and DnaJ heat shock protein family member C30 (DNAJC30) are differentially expressed in breast muscle between white recessive rock chicken (WRR) and Xinghua chicken (XH). In this study, we further characterize the potential function and SNP mutation of CRELD1 and DNAJC30 in chicken for the first time. According to protein interaction network and enrichment analysis, CRELD1 and DNAJC30 may play some roles in chicken muscle development and fat deposition. In WRR and XH, the results of the relative tissue expression pattern demonstrated that CRELD1 and DNAJC30 are not only differentially expressed in breast muscle but also leg muscle and abdominal fat. Therefore, we identified 5 SNP sites of CRELD1 and 7 SNP sites of DNAJC30 and genotyped them in an F2 chicken population. There are 4 sites of CRELD1 and 3 sites of DNAJC30 are associated with chicken carcass traits like breast muscle weight, body weight, dressed weight, leg weight percentage, eviscerated weight with giblet percentage, intermuscular adipose width, shank length, and girth. These results suggest that the SNP sites of CRELD1 and DNAJC30 can be potential molecular markers to improve the chicken carcass traits and lay the foundation for marker-assisted selection.

PPARGC1A Is a Moderator of Skeletal Muscle Development Regulated by miR-193b-3p.

Meat production performance is one of the most important factors in determining the economic value of poultry. Myofiber is the basic unit of skeletal muscle, and its physical and chemical properties determine the meat quality of livestock and poultry to a certain extent. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) as a transcriptional coactivator has been found to be widely involved in a series of biological processes. However, PPARGC1A is still poorly understood in chickens. In this manuscript, we reported that PPARGC1A was highly expressed in slow-twitch myofibers. PPARGC1A facilitated mitochondrial biogenesis and regulated skeletal muscle metabolism by mediating the flux of glycolysis and the TCA cycle. Gain- and loss-of-function analyses revealed that PPARGC1A promoted intramuscular fatty acid oxidation, drove the transformation of fast-twitch to slow-twitch myofibers, and increased chicken skeletal muscle mass. Mechanistically, the expression level of PPARGC1A is regulated by miR-193b-3p. Our findings help to understand the genetic regulation of skeletal muscle development and provide a molecular basis for further research on the antagonism of skeletal muscle development and fat deposition in chickens.

Influence of Eimeria maxima coccidia infection on gut microbiome diversity and composition of the jejunum and cecum of indigenous chicken.

Coccidiosis is an economically significant protozoan disease and an intracellular parasite that significantly impacts poultry production. The gastrointestinal tract microbiota plays a central role in host health and metabolism, and these microbes enhance chickens' immune systems and nutrient absorption. In this study, we analyzed the abundance and diversity of microbiota of the jejunum and cecum of a dual-purpose indigenous Horro chicken following Eimeria maxima infection. We compared microbial abundance, composition, and diversity at the 4- and 7- days post-infection using 16S rRNA gene sequencing. We obtained, on average, 147,742 and 132,986 high-quality sequences per sample for jejunum and cecum content, respectively. Firmicutes, Proteobacteria, Campilobacterota and Bacteroidota were the major microbial phylum detected in the jejunum content. Firmicutes were the dominant phylum for 4- and 7-days jejunum control groups accounting for (>60% of the sequences). In the infected group Campilobacterota was the dominant phylum in the jejunum (> 24% of sequences) at 4-and 7-days post-infection groups, while Proteobacteria was predominant at 4- and 7-days post-infection of the cecum (> 40% of the sequences). The microbial genus Lactobacillus and Helicobacter were found in the jejunum, while Alistipes, Barnesiella and Faecalibacterium were detected in the cecum. In the jejunum, Helicobacter was dominant at 4 -and-7 days post-infection (≥24%), and Lactobacillus was dominant at 4 -and 7- days in the control group (> 50%). In 4- and 7-days post-infection, Alistipes genus was the more prevalent (> 38%) in the cecum. Thus, clear differences were observed in the bacterial microbiota distribution and abundance between the jejunum and cecum, as well as between infected and control groups for both tissues. The results indicate that chicken intestinal microbial imbalance (dysbiosis) is associated with Eimeria parasite infection and will likely affect the host-microbial non-pathogenic and pathogenic molecular interactions.

Myogenic Determination and Differentiation of Chicken Bone Marrow-Derived Mesenchymal Stem Cells under Different Inductive Agents.

Poultry plays an important role in the meat consumer market and is significant to further understanding the potential mechanism of muscle development in the broiler. Bone marrow-derived mesenchymal stem cells (BM-MSCs) can provide critical insight into muscle development due to their multi-lineage differentiation potential. To our knowledge, chicken BM-MSCs demonstrate limited myogenic differentiation potential under the treatment with dexamethasone (DXMS) and hydrocortisone (HC). 5-azacytidine (5-Aza), a DNA demethylating agent, which has been widely used in the myogenic differentiation of BM-MSCs in other species. There is no previous report that applies 5-Aza to myogenic-induced differentiation of chicken BM-MSCs. In this study, we evaluated the myogenic determination and differentiation effect of BM-MSCs under different inductive agents. BM-MSCs showed better differentiation potential under the 5-Aza-treatment. Transcriptome sequence analysis identified 2402 differentially expressed DEGs including 28 muscle-related genes after 5-Aza-treatment. The DEGs were significantly enriched in Gene Ontology database terms, including in the cell plasma membrane, molecular binding, and cell cycle and differentiation. KEGG pathway analysis revealed that DEGs were enriched in myogenic differentiation-associated pathways containing the PI3K-Akt signaling pathway, the TGF-ß signaling pathway, Arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, and hypertrophic cardiomyopathy, which suggested that BM-MSCs differentiated into a muscle-like phenotype under 5-Aza-treatment. Although BM-MSCs have not formed myotubes in our study, it is worthy of further study. In summary, our study lays the foundation for constructing a myogenic determination and differentiation model in chicken BM-MSCs.

LncRNA SMARCD3-OT1 Promotes Muscle Hypertrophy and Fast-Twitch Fiber Transformation via Enhancing SMARCD3X4 Expression.

Long noncoding RNA (lncRNA) plays a crucial part in all kinds of life activities, especially in myogenesis. SMARCD3 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily d, member 3) is a member of the SWI/SNF protein complex and was reported to be required for cell proliferation and myoblast differentiation. In this study, we identified a new lncRNA named SMARCD3-OT1 (SMARCD3overlappinglncRNA), which strongly regulated the development of myogenesis by improving the expression of SMARCD3X4 (SMARCD3transcripts4). We overexpressed and knockdown the expression of SMARCD3-OT1 and SMARCD3X4 to investigate their function on myoblast proliferation and differentiation. Cell experiments proved that SMARCD3-OT1 and SMARCD3X4 promoted myoblast proliferation through the CDKN1A pathway and improved differentiation of differentiated myoblasts through the MYOD pathway. Moreover, they upregulated the fast-twitch fiber-related genes and downregulated the slow-twitch fiber-related genes, which indicated that they facilitated the slow-twitch fiber to transform into the fast-twitch fiber. The animals' experiments supported the results above, demonstrating that SMARCD3-OT1 could induce muscle hypertrophy and fast-twitch fiber transformation. In conclusion, SMARCD3-OT1 can improve the expression of SMARCD3X4, thus inducing muscle hypertrophy. In addition, SMARCD3-OT1 can facilitate slow-twitch fibers to transform into fast-twitch fibers.

Long noncoding RNA ZFP36L2-AS functions as a metabolic modulator to regulate muscle development.

Skeletal muscle is the largest metabolic organ in the body, and its metabolic flexibility is essential for maintaining systemic energy homeostasis. Metabolic inflexibility in muscles is a dominant cause of various metabolic disorders, impeding muscle development. In our previous study, we found lncRNA ZFP36L2-AS (for "ZFP36L2-antisense transcript") is specifically enriched in skeletal muscle. Here, we report that ZFP36L2-AS is upregulated during myogenic differentiation, and highly expressed in breast and leg muscle. In vitro, ZFP36L2-AS inhibits myoblast proliferation but promotes myoblast differentiation. In vivo, ZFP36L2-AS facilitates intramuscular fat deposition, as well as activates fast-twitch muscle phenotype and induces muscle atrophy. Mechanistically, ZFP36L2-AS interacts with acetyl-CoA carboxylase alpha (ACACA) and pyruvate carboxylase (PC) to induce ACACA dephosphorylation and damaged PC protein stability, thus modulating muscle metabolism. Meanwhile, ZFP36L2-AS can activate ACACA to reduce acetyl-CoA content, which enhances the inhibition of PC activity. Our findings present a novel model about the regulation of lncRNA on muscle metabolism.

PGC-1α affects skeletal muscle and adipose tissue development by regulating mitochondrial biogenesis.

The discovery and interpretation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) protein in mitochondrial biogenesis, skeletal muscle and adipose tissue development has broad research prospects, so it is important to review the related studies of PGC-1α in detail and comprehensively. PGC-1α is a protein composed of 798 amino acids (aa) with a molecular weight of about 91 kDa. PGC-1α is involved in the operation of the respiratory chain by combining with deacetylase and phosphorylase to bind some nuclear receptors. In addition, PGC-1α affects skeletal muscle and adipose metabolism by regulating mitochondrial oxidative phosphorylation. Recently, new data suggest that regulating mitochondrial metabolism in adipose tissue may be an effective adjunct to the treatment of obesity. In addition, dietary resveratrol, which has an effective anti-obesity effect, has been shown to promote mitochondrial biosynthesis by activating AMPK/PGC-1α axis, as well as to regenerate muscle damaged by obesity. In this review, we combined previous studies to explore the latest studies, showing that PGC-1α can regulate mitochondrial biogenesis and is regulated by AMPK and SIRT1. Furthermore, PGC-1α is a favored protein, which not only regulates muscle fiber type, inhibits muscle atrophy, but also participates in browning of white adipose tissue (WAT) and regulates body heat production. So, we concluded that PGC-1α is a key gene in mitochondrial biogenesis and plays an important role in the regulation and regulation of mitochondrial biogenesis along with other genes involved in the process. Meanwhile, PGC-1α acts as a core metabolic regulator in adipose tissue and skeletal muscle. This review comprehensively summarizes a large number of research findings. First, the role of PGC-1α in mitochondrial biogenesis was clarified, and then the key role of PGC-1α in the development of skeletal muscle and adipose tissue was reevaluated. Furthermore, the role of PGC-1α in some human diseases was discussed. Finally, the role of PGC-1α as a major gene in poultry was pointed out, and the future research direction was proposed.

circPTPN4 regulates myogenesis via the miR-499-3p/NAMPT axis.

BACKGROUND: Circular RNAs (circRNAs) are a novel class of endogenous ncRNA, which widely exist in the transcriptomes of different species and tissues. Recent studies indicate important roles for circRNAs in the regulation of gene expression by acting as competing endogenous RNAs (ceRNAs). However, the specific role of circRNAs in myogenesis is still poorly understood. In this study, we attempted to systematically identify the circRNAs involved in myogenesis and analyze the biological functions of circRNAs in chicken skeletal muscle development. RESULTS: In total, 532 circRNAs were identified as being differentially expressed between pectoralis major (PEM) and soleus (SOL) in 7-week-old Xinghua chicken. Among them, a novel circRNA (novel_circ_002621), generated by PTPN4 gene, was named circPTPN4 and identified. circPTPN4 is highly expressed in skeletal muscle, and its expression level is upregulated during myoblast differentiation. circPTPN4 facilitates the proliferation and differentiation of myoblast. Moreover, circPTPN4 suppresses mitochondria biogenesis and activates fast-twitch muscle phenotype. Mechanistically, circPTPN4 can function as a ceRNA to regulate NAMPT expression by sponging miR-499-3p, thus participating in AMPK signaling. CONCLUSIONS: circPTPN4 functions as a ceRNA to regulate NAMPT expression by sponging miR-499-3p, thus promoting the proliferation and differentiation of myoblast, as well as activating fast-twitch muscle phenotype.

LncEDCH1 improves mitochondrial function to reduce muscle atrophy by interacting with SERCA2.

Skeletal muscle is a regulator of the body's energy expenditure and metabolism. Abnormal regulation of skeletal muscle-specific genes leads to various muscle diseases. Long non-coding RNAs (lncRNAs) have been demonstrated to play important roles in muscle growth and muscle atrophy. To explore the potential function of muscle-associated lncRNA, we analyzed our previous RNA-sequencing data and selected the lncRNA (LncEDCH1) as the research object. In this study, we report that LncEDCH1 is specifically enriched in skeletal muscle, and its transcriptional activity is positively regulated by transcription factor SP1. LncEDCH1 regulates myoblast proliferation and differentiation in vitro. In vivo, LncEDCH1 reduces intramuscular fat deposition, activates slow-twitch muscle phenotype, and inhibits muscle atrophy. Mechanistically, LncEDCH1 binds to sarcoplasmic/ER calcium ATPase 2 (SERCA2) protein to enhance SERCA2 protein stability and increase SERCA2 activity. Meanwhile, LncEDCH1 improves mitochondrial efficiency possibly through a SERCA2-mediated activation of the AMPK pathway. Our findings provide a strategy for using LncEDCH1 as an effective regulator for the treatment of muscle atrophy and energy metabolism.

Long noncoding RNA SMUL suppresses SMURF2 production-mediated muscle atrophy via nonsense-mediated mRNA decay.

As the world population grows, muscle atrophy leading to muscle wasting could become a bigger risk. Long noncoding RNAs (lncRNAs) are known to play important roles in muscle growth and muscle atrophy. Meanwhile, it has recently come to light that many putative small open reading frames (sORFs) are hidden in lncRNAs; however, their translational capabilities and functions remain unclear. In this study, we uncovered 104 myogenic-associated lncRNAs translated, in at least a small peptide, by integrated transcriptome and proteomic analyses. Furthermore, an upstream ORF (uORF) regulatory network was constructed, and a novel muscle atrophy-associated lncRNA named SMUL (Smad ubiquitin regulatory factor 2 [SMURF2] upstream lncRNA) was identified. SMUL was highly expressed in skeletal muscle, and its expression level was downregulated during myoblast differentiation. SMUL promoted myoblast proliferation and suppressed differentiation in vitro. In vivo, SMUL induced skeletal muscle atrophy and promoted a switch from slow-twitch to fast-twitch fibers. In the meantime, translation of the SMUL sORF disrupted the stability of SMURF2 mRNA. Mechanistically, SMUL restrained SMURF2 production via nonsense-mediated mRNA decay (NMD), participating in the regulation of the transforming growth factor ß (TGF-ß)/SMAD pathway and further regulating myogenesis and muscle atrophy. Taken together, these results suggest that SMUL could be a novel therapeutic target for muscle atrophy.

Absolute phase measurement with four patterns based on variant shifting phases.

Fringe projection profilometry has been proverbially utilized for measuring the shapes of objects. A common challenge in those systems is to accurately obtain a smooth absolute phase. Many new methods have been proposed to address this challenge. In this paper, we discuss a technique based on variant shifting phases. This approach embeds codewords into the shifting phase and only needs four patterns. However, reliable measurement results are difficult to achieve with a large number of codewords because of the phase errors. To address this shortcoming, we present a robust coding method that embeds a specific code sequence into the shifting phase and can generate more than 36 periods. The fringe order is determined using unique three-adjacent-codes combining the current period and its neighbors. An error correction algorithm is also proposed to optimize the codewords. The proposed method is experimentally verified using an established measurement system. The result shows that the proposed method is robust and efficient.