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In order to improve the accuracy of coal and gas outburst risk prediction for an excavation face, an outburst equilibrium equation for the excavation face was established based on the Mohr–Coulomb criterion to predict the coal and gas outburst risk for the excavation face. The numerical model was established using the COMSOL Multiphysics simulation software to explore the relationship between the initial gas emissions from the borehole and the gas pressure. Using a ZTL20/1000-Z mine flameproof prediction device, taking excavation face 9301 in the Anshun Coal Mine in Guizhou Province, China, as the research object, and taking the detailed regulations for prevention and control of coal and gas outburst promulgated by the China Coal Mine Safety Supervision Bureau in 2019 as the prediction standard for coal and gas outbursts, an experiment on the outburst risk prediction for the excavation face was conducted. The results show that the gas pressure measured in the borehole is positively correlated with the initial gas emissions, and the initial gas flow can be used as a sensitive index to predict the outburst risk of the excavation face. The initial gas flow increases as the borehole depth increases, and it tends to be stable in the later stage. The initial borehole gas flow can not only reflect the outburst risk but also reveal the possible location of the outburst, which has obvious advantages over other outburst prediction indexes. [ABSTRACT FROM AUTHOR]

Background: Coloration is one of the most recognizable characteristics in chickens, and clarifying the coloration mechanisms will help us understand feather color formation. "Yufen I" is a commercial egg-laying chicken breed in China that was developed by a three-line cross using lines H, N and D. Columbian plumage is a typical feather character of the "Yufen I" H line. To elucidate the molecular mechanism underlying the pigmentation of Columbian plumage, this study utilizes high-throughput sequencing technology to compare the transcriptome and proteome differences in the follicular tissue of different feathers, including the dorsal neck with black and white striped feather follicles (Group A) and the ventral neck with white feather follicles (Group B) in the "Yufen I" H line. Results: In this study, we identified a total of 21,306 genes and 5,203 proteins in chicken feather follicles. Among these, 209 genes and 382 proteins were differentially expressed in two locations, Group A and Group B, respectively. A total of 8 differentially expressed genes (DEGs) and 9 differentially expressed proteins (DEPs) were found to be involved in the melanogenesis pathway. Additionally, a specifically expressed MED23 gene and a differentially expressed GNAQ protein were involved in melanin synthesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis mapped 190 DEGs and 322 DEPs to 175 and 242 pathways, respectively, and there were 166 pathways correlated with both DEGs and DEPs. 49 DEPs/DEGs overlapped and were enriched for 12 pathways. Transcriptomic and proteomic analyses revealed that the following pathways were activated: melanogenesis, cardiomyocyte adrenergic, calcium and cGMP-PKG. The expression of DEGs was validated by real-time quantitative polymerase chain reaction (qRT-PCR) that produced results similar to those from RNA-seq. In addition, we found that the expression of the MED23, FZD10, WNT7B and WNT11 genes peaked at approximately 8 weeks in the "Yufen I" H line, which is consistent with the molting cycle. As both groups showed significant differences in terms of the expression of the studied genes, this work opens up avenues for research in the future to assess their exact function in determining plumage color. Conclusion: Common DEGs and DEPs were enriched in the melanogenesis pathway. MED23 and GNAQ were also reported to play a crucial role in melanin synthesis. In addition, this study is the first to reveal gene and protein variations in in the "Yufen I" H line during Columbian feather color development and to discover principal genes and proteins that will aid in functional genomics studies in the future. The results of the present study provide a significant conceptual basis for the future breeding schemes with the "Yufen I" H line and provide a basis for research on the mechanisms of feather pigmentation. [ABSTRACT FROM AUTHOR]

The Xichuan black-bone chicken, which is a rare local chicken species in China, is an important genetic resource of black-bone chickens. Tyrosine can affect melanin production, but the molecular mechanism underlying tyrosine-induced melanin deposition in Xichuan black-bone chickens is poorly understood. Here, the blackness degree and melanin content of the breast muscle of Xichuan black-bone chickens fed a basic diet with five levels of added tyrosine (i.e., 0.2, 0.4, 0.6, 0.8, and 1.0%; these groups were denoted test groups I-V, respectively) were assessed, and the results showed that 0.8% tyrosine was the optimal level of added tyrosine. Moreover, the effects of tyrosine supplementation on the proliferation and tyrosinase content of melanocytes in Xichuan black-bone chickens were evaluated. The results revealed a dose-dependent relationship between tyrosine supplementation and melanocyte proliferation. In addition, 417 differentially expressed genes (DEGs), including 160 upregulated genes and 257 downregulated genes, were identified in a comparative analysis of the transcriptome profiles constructed using the pooled total RNA from breast muscle tissues of the control group and test group IV, respectively (fold change ≥2.0, P < 0.05). These DEGs were mainly involved in melanogenesis, the calcium signaling pathway, the Wnt signaling pathway, the mTOR signaling pathway, and vascular smooth muscle contraction. The pathway analysis of the DEGs identified some key genes associated with pigmentation, such as DCT and EDNRB2. In summary, the melanin content of breast muscle could be markedly enhanced by adding an appropriate amount of tyrosine to the diet of Xichuan black-bone chickens, and the EDNRB2 -mediated molecular regulatory network could play a key role in the biological process of tyrosine-induced melanin deposition. These results have deepened the understanding of the molecular regulatory mechanism of melanin deposition in black-bone chickens and provide a basis for the regulation of nutrition and genetic breeding associated with melanin deposition in Xichuan black-bone chickens. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNAs) play important roles in transcriptional and posttranscriptional regulation. However, the effects of lncRNAs on the meat quality of chicken hasn’t been elucidated clearly yet. Gushi chickens are popular in China because of their superior meat quality, particularly the tender flesh, and unique flavor. Gushi chickens are popular in China because of their superior meat quality, delicate flesh, and unique flavor. We performed RNA-Seq analysis of breast muscle from Gushi chicken at two physiological stages, including juvenile (G20W) and laying (G55W). In total, 186 lncRNAs and 881 mRNAs were differentially expressed between G20W and G55W (fold change ≥ 2.0, P < 0.05). Among them, 131 lncRNAs presented upregulated and 55 were downregulated. We identified the cis and trans target genes of the differentially expressed lncRNAs, and constructed lncRNA-mRNA interaction networks. The results showed that differentially expressed mRNAs and lncRNAs were mainly involved in ECM-receptor interaction, glycerophospholipid metabolism, ubiquitin-mediated proteolysis, and the biosynthesis of amino acids. In summary, our study utilized RNA-seq analysis to predict the functions of lncRNA on chicken meat quality. Furthermore, comprehensive analysis identified lncRNAs and their target genes, which may contribute to a better understanding of the molecular mechanisms underlying in poultry meat quality and provide a theoretical basis for further research. [ABSTRACT FROM AUTHOR]

The large economic losses caused by leg disorders have raised concerns in the broiler industry. Several types of leg disorders in broilers have been identified, such as tibial dyschondroplasia (TD), femoral head necrosis (FHN), and valgus-varus deformity (VVD). In this study, phenotypic changes associated with VVD were examined using clinical diagnosis, anatomical examination, measured growth performance, bone traits, and serum indicators. The incidence of VVD among the chicken population at a commercial facility in Tangshan China was 1.75% (n = 52,000), distributed about 1:1 (n = 122), between females and males. A majority of chickens were characterized by a unilaterally abnormality, while appropriately 17.6% by bilateral abnormality. Approximately 97.9% of affected broilers were classified as the "valgus" type. Growth traits, including body weight, shank length, and shank girth, were significantly lower in chickens with VVD, while tibia and metatarsal bone indexes were about 1.3-fold higher in the affected birds than in the normal birds. Bone mineral density, bone breaking strength, and several serum indicators were significantly different between affected and normal broilers. Sparse and disarranged bony trabecular was observed in abnormal broilers by histological analysis. Generally, leg disorders are associated with compromised growth, bone quality, bone structure, and lipid metabolism. This study provides a reference for clinical diagnosis of VVD and lays a foundation for exploring its underlying mechanisms. [ABSTRACT FROM AUTHOR]

Background: Chicken skeletal muscle is an important economic product. The late stages of chicken development constitute the main period that affects meat production. LncRNAs play important roles in controlling the epigenetic process of growth and development. However, studies on the role of lncRNAs in the late stages of chicken breast muscle development are still lacking. In this study, to investigate the expression characteristics of lncRNAs during chicken muscle development, 12 cDNA libraries were constructed from Gushi chicken breast muscle samples from 6-, 14-, 22-, and 30-week-old chickens., Results: A total of 1252 new lncRNAs and 1376 annotated lncRNAs were identified. Furthermore, 53, 61, 50, 153, 117, and 78 DE-lncRNAs were found in the W14 vs. W6, W22 vs. W14, W22 vs. W6, W30 vs. W6, W30 vs. W14, and W30 vs. W22 comparison groups, respectively. After GO enrichment analysis of the DE-lncRNAs, several muscle development-related GO terms were found in the W22 vs. W14 comparison group. Moreover, it was found that the MAPK signaling pathway was one of the most frequently enriched pathways in the different comparison groups. In addition, 12 common target DE-miRNAs of DE-lncRNAs were found in different comparison groups, some of which were muscle-specific miRNAs, such as gga-miR-206, gga-miR-1a-3p, and miR-133a-3p. Interestingly, the precursors of four newly identified miRNAs were found to be homologous to lncRNAs. Additionally, we found some ceRNA networks associated with muscle development-related GO terms. For example, the ceRNA networks contained the DYNLL2 gene with 12 lncRNAs that targeted 2 miRNAs. We also constructed PPI networks, such as IGF-I-EGF and FZD6-WNT11., Conclusions: This study revealed, for the first time, the dynamic changes in lncRNA expression in Gushi chicken breast muscle at different periods and revealed that the MAPK signaling pathway plays a vital role in muscle development. Furthermore, MEF2C and its target lncRNA may be involved in muscle regulation through the MAPK signaling pathway. This research provided valuable resources for elucidating posttranscriptional regulatory mechanisms to promote the development of chicken breast muscles after hatching.