Poultry is an important dietary source of animal protein, accounting for approximately 30% of global meat consumption. Because of its low price, low fat and cholesterol content, and no religious restrictions, chicken is considered a widely available healthy meat. Chahua chicken No. 2 is a synthetic breed of Chahua chicken derived from five generations of specialized strain breeding. In this study, Chahua chicken No. 2 (CH) and Yao chicken (Y) were used as the research objects to compare the differences in physicochemical and nutritional indicators of meat quality between the two chicken breeds, and metabolomics was used to analyze the differences in metabolites and lipid metabolism pathways and to explore the expression of genes involved in adipogenesis. The physical index and nutritional value of CH are better than that of Y, and the chemical index of Y is better than that of CH. However, the chemical index results of CH are also within the normal theoretical value range. Comprehensive comparison shows that the meat quality of CH is relatively good. Metabolomics analysis showed that CH and Y had 85 different metabolites, and the differential metabolites were mainly classified into eight categories. KEGG pathway enrichment analysis revealed 13 different metabolic pathways. The screened PPARG, FABP3, ACSL5, FASN, UCP3 and SC5D were negatively correlated with muscle fat deposition, while PPARα, ACACA and ACOX1 were positively correlated with muscle fat deposition. The meat quality of CH was better than Y. The metabolites and metabolic pathways obtained by metabonomics analysis mainly involved the metabolism of amino acids and fatty acids, which were consistent with the differences in meat quality between the two breeds and the contents of precursors affecting flavor. The screened genes were associated with fatty deposition in poultry.

Meat quality traits are an important economic trait and remain a major argument, from the producer to the consumer. However, there are a few candidate genes and pathways of chicken meat quality traits that were reported for chicken molecular breeding. The purpose of the present study is to identify the candidate genes and pathways associated with meat quality underlying variations in meat quality. Hence, transcriptome profiles of breast tissue in commercial Digao (DG, 5 male) and Chahua (CH, 5 male) native chicken breeds were analyzed at the age of 100 days. The results found 3525 differentially expressed genes (DEGs) in CH compared to DG with adjusted p-values of ≤0.05 and log2FC ≥ 0.1 FDR ≤ 0.05. Functional analysis of GO showed that the DEGs are mainly involved in the two types of processes of meat quality, such as positive regulation of the metabolic process, extracellular structure organization, collagen trimer, cellular amino acid metabolic process, cellular amino acid catabolic process, and heme binding. Functional analysis of KEGG showed that the DEGs are mainly involved in the two types of processes of meat quality, such as oxidative phosphorylation, carbon metabolism, valine, leucine, and isoleucine degradation, and fatty acid degradation. Many of the DEGs are well known to be related to meat quality, such as COL28A1, COL1A2, MB, HBAD, HBA1, ACACA, ACADL, ACSL1, ATP8A1, CAV1, FADS2, FASN, DCN, CHCHD10, AGXT2, ALDH3A2, and MORN4. Therefore, the current study detected multiple pathways and genes that could be involved in the control of the meat quality traits of chickens. These findings should be used as an essential resource to improve the accuracy of selection for meat traits in chickens using marker-assisted selection based on differentially expressed genes.

Single-cell sequencing (SCS) uses a single cell as the research material and involves three dimensions: genes, phenotypes and cell biological mechanisms. This type of research can locate target cells, analyze the dynamic changes in the target cells and the relationships between the cells, and pinpoint the molecular mechanism of cell formation. Currently, a common problem faced by animal husbandry scientists is how to apply existing science and technology to promote the production of high-quality livestock and poultry products and to breed livestock for disease resistance; this is also a bottleneck for the sustainable development of animal husbandry. In recent years, although SCS technology has been successfully applied in the fields of medicine and bioscience, its application in poultry science has been rarely reported. With the sustainable development of science and technology and the poultry industry, SCS technology has great potential in the application of poultry science (or animal husbandry). Therefore, it is necessary to review the innovation of SCS technology and its application in poultry science. This article summarizes the current main technical methods of SCS and its application in poultry, which can provide potential references for its future applications in precision breeding, disease prevention and control, immunity, and cell identification.

Poultry is a source of meat that is in great demand in the world. The quality of meat is an imperative point for shoppers. To explore the genes controlling meat quality characteristics, the growth and meat quality traits and muscle transcriptome of two indigenous Yunnan chicken breeds, Wuding chickens (WDs) and Daweishan mini chickens (MCs), were compared with Cobb broilers (CBs). The growth and meat quality characteristics of these two indigenous breeds were found to differ from CB. In particular, the crude fat (CF), inosine monophosphate content, amino acid (AA), and total fatty acid (TFA) content of WDs were significantly higher than those of CBs and MCs. In addition, it was found that MC pectoralis had 420 differentially expressed genes (DEGs) relative to CBs, and WDs had 217 DEGs relative to CBs. Among them, 105 DEGs were shared. The results of 10 selected genes were also confirmed by qPCR. The differentially expressed genes were six enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathways including lysosomes, phagosomes, PPAR signaling pathways, cell adhesion molecules, cytokine–cytokine receptor interaction, and phagosome sphingolipid metabolism. Interestingly, four genes (LPL, GK, SCD, and FABP7) in the PPAR signal pathway related to fatty acid (FA) metabolism were elevated in WD muscles, which may account for higher CF, inosine monophosphate content, and AA and FA contents, key factors affecting meat quality. This work laid the foundation for improving the meat quality of Yunnan indigenous chickens, especially WD. In future molecular breeding, the genes in this study can be used as molecular screening markers and applied to the molecular breeding of chicken quality characteristics.

Native chicken has become a favorite choice for consumers in many Asian countries recently, not only for its potential nutritional value but also for its deep ties to local food culture. However, low growth performance and limited meat production restrict their economic potential. Conducting a genome-wide association study (GWAS) for chicken-breast muscle development will help identify loci or candidate genes for different traits and potentially provide new insight into this phenotype in chickens and other species. To improve native chicken growth performance, especially breast muscle development, we performed a GWAS to explore the potential genetic mechanisms of breast muscle development in an F2 population constructed by reciprocal crosses between a fast-growing broiler chicken (Cobb500) and a slow-growing native chicken (Daweishan mini chicken). The results showed that 11 SNPs, which exceeded the 10% genome significance level (p = 1.79 × 10⁻⁸) were considered associated with breast muscle development traits, where six SNPS, NC_006126.5: g.3138376T>G, NC_006126.5: g.3138452A>G, NC_006088.5: g.73837197A>G, NC_006088.5: g.159574275A>G, NC_006089.5: g.80832197A>G, and NC_006127.5: g.48759869G>T was first identified in this study. In total, 13 genes near the SNPs were chosen as candidate genes, and none of them had previously been studied for their role in breast muscle development. After grouping the F2 population according to partial SNPs, significant differences in breast muscle weight were found among different genotypes (p < 0.05), and the expression levels of ALOX5AP, USPL1, CHRNA9, and EFNA5 among candidate genes were also significantly different (p < 0.05). The results of this study will contribute to the future exploration of the potential genetic mechanisms of breast muscle development in domestic chickens and also support the expansion of the market for native chicken in the world.

Tengchong snow, which has white feathers and black meat, is one of the most important black-bone chicken breeds and a genetic treasure of black food in China. Although the black meat traits are dominant, there are some chickens with white meat traits born in the process of folk selection and breeding. The purpose of this study was to compare the differences in skeletal muscle development between Tengchong snow black meat chickens (BS) and white meat chickens (WS), as well as whether excessive melanin deposition has an effect on skeletal muscle development. The BS and WS groups were selected to determine their muscle development difference at stages of 1, 7, 14, 21, and 42 days, using histological stain methods to analyze the development and composing type of breast and leg muscle fibers, as well as the count of melanin in BS muscle fibers. Finally, we were validated key candidate genes associated with muscle development and melanin synthesis. The results showed that BS breast muscle development was inhibited at 7, 14, and 21 days, while the leg muscle was inhibited at 7, 14, 21, and 42 days, compared to WS. Melanin deposition was present in a temporal migration pattern and was greater in the leg muscles than in the breast muscles, and it focused around blood vessels, as well as the epithelium, perimysium, endomysium, and connective tissue. Additionally, melanin produced an inhibitory effect similar to MSTN during skeletal muscle fiber development, and the inhibition was strongest at the stage of melanin entry between muscle fibers, but the precise mechanisms need to be confirmed. This study revealed that melanin has an inhibitory effect on the early development of skeletal muscle, which will provide new insights into the role of melanin in the black-boned chicken and theoretical references for the future conservation and utilization of black-boned chicken.