Genome-wide association study of myofiber type composition traits in a yellow-feather broiler population.

Meat quality is a key factor determining the economic viability of the broiler industry, particularly in native broiler breeds. Skeletal muscles contain a mixture of muscle fibers, each possessing unique physicochemical properties; the composition of myofiber types within these muscles is closely linked to meat quality. However, comprehension of the regulatory mechanisms governing this trait remains limited.

METTL16 inhibits differentiation and promotes proliferation and slow myofibers formation in chicken myoblasts.

N6-methyladenosine (m6A) plays a crucial regulatory role in muscle growth and development. In our previous studies, we identified a m6A methyltransferase, Methyltransferase like 16 (METTL16), which is associated with chicken muscle development and muscle fiber type conversion. To further understand the regulatory role of METTL16 in chicken muscle function, we analyzed its expression in muscle tissues with different myofiber type compositions and in chicken primary myoblasts (CPMs) at various stages.

Dynamic Transcriptome Profile Analysis of Mechanisms Related to Melanin Deposition in Chicken Muscle Development.

The pectoral muscle is an important component of skeletal muscle. The blackness of pectoral muscles can directly affect the economic value of black-boned chickens. Although the genes associated with melanogenesis in mammals and birds have been thoroughly investigated, only little is known about the key genes involved in muscle hyperpigmentation during embryonic development.

Molecular Regulatory Mechanisms in Chicken Feather Follicle Morphogenesis.

In China, the sale of freshly slaughtered chickens is becoming increasingly popular in comparison with that of live chickens, and due to this emerging trend, the skin and feather follicle traits of yellow-feathered broilers have attracted a great deal of research attention. The feather follicle originates from the interaction between the epidermis and dermis in the early embryonic stage. Feather follicle morphogenesis is regulated by the Wnt, ectodysplasin (Eda), epidermal growth factor (EGF), fibroblast growth factor (FGF), bone morphogenetic protein (BMP), sonic hedgehog (Shh), Notch, and other signaling pathways that exist in epithelial and mesenchymal cells.

Transcriptome sequencing analysis of the role of miR-499-5p and in chicken skeletal myofiber specification.

MicroRNAs (miRNAs) might play critical roles in skeletal myofiber specification. In a previous study, we found that chicken miR-499-5p is specifically expressed in slow-twitch muscle and that its potential target gene is . In this study, we performed RNA sequencing to investigate the effects of and miR-499-5p on the modulation and regulation of chicken muscle fiber type and its regulatory mechanism.

Population Structure and Genetic Diversity of Seven Chinese Indigenous Chicken Populations in Guizhou Province.

To investigate the population structure and genetic diversity of indigenous chicken breeds in Guizhou, a total of 150 individual samples were collected from 12 breeds, including seven local chicken breeds in Guizhou Province, three Chinese native breeds found in other provinces, and two commercial breeds. The genotype datasets were obtained using a 50K single nucleotide polymorphism array method, and then a series of population analyses were performed. The obtained population parameters and linkage disequilibrium decay indicated a higher degree of genetic diversity in Guizhou chickens than in commercial breeds.

Deep sequencing microRNA profiles associated with wooden breast in commercial broilers.

Wooden breast (WB) is a muscle disorder affecting modern commercial broiler chickens that leads to a palpable firm pectoralis major muscle and causes severe reduction in meat quality, resulting in substantial economic losses for the poultry industry. Most studies have focused on the regulatory mechanisms underlying this defect with respect to the gene and protein expression levels as well as the levels of metabolites. MicroRNAs (miRNAs) play critical roles in human muscular disorders, such as the Duchenne muscular dystrophy, by regulating the muscle regeneration or fibrosis processes.

Analysis of potential regulatory LncRNAs and CircRNAs in the oxidative myofiber and glycolytic myofiber of chickens.

SART and PMM are mainly composed of oxidative myofibers and glycolytic myofibers, respectively, and myofiber types profoundly influence postnatal muscle growth and meat quality. SART and PMM are composed of lncRNAs and circRNAs that participate in myofiber type regulation. To elucidate the regulatory mechanism of myofiber type, lncRNA and circRNA sequencing was used to systematically compare the transcriptomes of the SART and PMM of Chinese female Qingyuan partridge chickens at their marketing age.

Identifying Signatures of Selection Related to Comb Development.

The aim of this study was to identify genes involved in comb development to provide insights into the molecular mechanism of chickens' comb formation. Fixation index (F) and average number of base differences () of males with large and small combs were calculated based on whole-genome resequencing data. Chromosome regions with larger F values and smaller were considered candidate selection regions.

miRNA-mRNA network regulation in the skeletal muscle fiber phenotype of chickens revealed by integrated analysis of miRNAome and transcriptome.

Skeletal muscle fibers are primarily categorized into oxidative and glycolytic fibers, and the ratios of different myofiber types are important factors in determining livestock meat quality. However, the molecular mechanism for determining muscle fiber types in chickens was hardly understood. In this study, we used RNA sequencing to systematically compare mRNA and microRNA transcriptomes of the oxidative muscle sartorius (SART) and glycolytic muscle pectoralis major (PMM) of Chinese Qingyuan partridge chickens.

A gene co-expression network analysis of the candidate genes and molecular pathways associated with feather follicle traits of chicken skin.

Back and thigh skin of chickens showed significant differences in the thickness and the feather follicle density and size, which are important traits for slaughtered chickens' appearance. In the present study, global gene expression profiling was conducted in the back and thigh skin of chickens using Microarray technology. The results showed that 676 genes were differentially expressed between back and thigh skin.

Molecular Cloning, Characterization, and Temporal Expression Profile of Troponin I Type 1 (TNNI1) Gene in Skeletal Muscle During Early Development of Gaoyou Duck (Anas Platyrhynchos Domestica).

TNNI1 encodes the slow skeletal muscle isoform of troponin I. In the present study, the basic characteristic and expressing profile of the TNNI1 gene was first explored in Gaoyou ducks. Full-length TNNI1 cDNA of Gaoyou duck was obtained using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE).

Identification of molecular pathways and candidate genes associated with cocks' comb size trait by genome-wide transcriptome analysis.

The comb of the male is an important secondary sexual characteristic. Although quantitative trait loci (QTLs) related to comb size have been identified, molecular mechanisms underlying this trait remain mostly unknown. In this study, RNA sequencing (RNA-seq) was employed to compare whole transcriptomic differences between two groups of Partridge Shank chickens that are divergent in comb sizes.

Oxidative and glycolytic skeletal muscles show marked differences in gene expression profile in Chinese Qingyuan partridge chickens.

Oxidative and glycolytic myofibers have different structures and metabolic characteristics and their ratios are important in determining poultry meat quality. However, the molecular mechanisms underlying their differences are unclear. In this study, global gene expression profiling was conducted in oxidative skeletal muscle (obtained from the soleus, or SOL) and glycolytic skeletal muscle (obtained from the extensor digitorum longus, or EDL) of Chinese Qingyuan partridge chickens, using the Agilent Chicken Gene Expression Chip.

Expression profile of IGF-I-calcineurin-NFATc3-dependent pathway genes in skeletal muscle during early development between duck breeds differing in growth rates.

The insulin-like growth factor I (IGF-I)-calcineurin (CaN)-NFATc signaling pathways have been implicated in the regulation of myocyte hypertrophy and fiber-type specificity. In the present study, the expression of the CnAα, NFATc3, and IGF-I genes was quantified by RT-PCR for the first time in the breast muscle (BM) and leg muscle (LM) on days 13, 17, 21, 25, and 27 of embryonic development, as well as at 7 days posthatching (PH), in Gaoyou and Jinding ducks, which differ in their muscle growth rates. Consistent expression patterns of CnAα, NFATc3, and IGF-I were found in the same anatomical location at different development stages in both duck breeds, showing significant differences in an age-specific fashion.

The relative expression levels of insulin-like growth factor 1 and myostatin mRNA in the asynchronous development of skeletal muscle in ducks during early development.

Genetic selection is a powerful tool for modifying poultry muscle yield. Insulin-like growth factor I (IGF-I) and myostatin (MSTN) are important regulators of muscle growth, especially in the myogenesis stage. This study compared the developmental pattern of the pectoralis major (PM) and lateral gastrocnemius (LM) muscles, mRNA expression characterization of IGF-I and MSTN-A and their correlation between 14 days in ovo and 1 week post-hatch in two Chinese local duck breeds.

Expression of insulin-like growth factor system genes in liver tissue during embryonic and early post-hatch development in duck (Anas platyrhynchos Domestica).

The IGF system is one of the most important endocrine and paracrine growth factor systems that regulate fetal and placental growth, whereas the liver is the principal source of circulation IGF-I. In the present study, expression of IGF-I, IGF type-I receptor (IGF-IR), and IGF binding protein (IGFBP)-3 genes was quantified by RT-PCR in the liver tissue on days 13, 17, 21, 25, and 27 of embryonic development, as well as at 7 days post-hatching (PH) in meat-type Gaoyou ducks and egg-type Jinding ducks. The results showed that IGF-I mRNA could be detected as early as on E 13d, but the expression level was low throughout embryonic development before increasing dramatically by E 27d and 7 days PH in both duck breeds.

Analysis of the genetic effects of prolactin gene polymorphisms on chicken egg production.

Chicken prolactin (PRL) is a physiological candidate gene for egg production. Variations of T8052C and G8113C in exon 5 of PRL gene may associate with chicken egg production. The objective of the study was to investigate the association of these two single nucleotide polymorphisms in PRL gene with egg production of Recessive White chickens and Qingyuan Partridge chickens.