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This study investigated the function of AMP deaminase 1 (AMPD1) in Jingyuan chicken and the biological activity of its expression vector. AMPD1 was cloned and sequenced from chicken breast muscle tissue by RT-PCR and further analyzed using Cluster, DNASTAR, and online bioinformatics software, as well as vector construction, qPCR, Western blotting, enzymatic digestion, and sequencing. The coding sequence was 2162 bp, encoding 683 amino acids and producing a protein of approximately 78.95 kDa. After verification, the overexpression plasmids pEGFP-AMPD1, Cas9/sgRNA2, and Cas9/sgRNA3 were found to have biological activity in chicken muscle cells and individual chickens, and two sgRNAs (sgRNA2, sgRNA3) were identified that could edit AMPD1. The qPCR and Western blotting result showed that the pEGFP-AMPD1 plasmid significantly increased both mRNA and protein expression of AMPD1. T7EI digestion showed editing efficiencies of approximately 35 %, 37 %, and 33 % for sgRNA2, sgRNA3, and sgRNA2 + sgRNA3 of AMPD1 in chicken muscle cells. In comparison, TA cloning sequencing showed editing efficiencies of approximately 36.7 %, 86.7 %, and 26.7 % and editing efficiencies in chicken individuals of approximately 71 %, 45 %, and 76.7 %, respectively. These results provide a theoretical basis and support for further investigation into the function of the AMPD1 gene., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Inosine monophosphate (IMP) plays a significant role in meat taste, yet the molecular mechanisms controlling IMP deposition in muscle tissues still require elucidation. The present study systematically and comprehensively explores the molecular network governing IMP deposition in different regions of Jingyuan chicken muscle. Two muscle groups, the breast and leg, were examined as test materials. Using nontargeted metabolomic sequencing, we screened and identified 20 metabolites that regulate IMP-specific deposition. We maintained regular author and institution formatting, used clear, objective, and value-neutral language, and avoided biased or emotional language. We followed a consistent footnote style and formatting features and used precise word choice with technical terms where appropriate. Out of these, 5 were identified as significant contributors to the regulation of IMP deposition. We explained technical term abbreviations when first used and ensured a logical flow of information with causal connections between statements. The results indicate that PGM1, a key enzyme involved in synthesis, is higher in the breast muscle compared to the leg muscle, which may provide an explanation for the increased deposition of IMP in the breast muscle. We aimed for a clear structure with logical progression, avoided filler words, and ensured grammatical correctness. The activity of key enzymes (PKM2, AK1, AMPD1) involved in this process was higher in the breast muscle than in the leg muscle. In the case of IMP degradation metabolism, the activity of its participating enzyme (PurH) was lower in the breast muscle than in the leg muscle. These findings suggest that the increased deposition of IMP in Jingyuan chickens' breast muscle may result from elevated metabolism and reduced catabolism of key metabolites. In summary, a metaomic strategy was utilized to assess the molecular network regulation mechanism of IMP-specific deposition in various segments of Jingyuan chicken. These findings provide insight into genetic improvement and molecular breeding of meat quality traits for top-notch broilers., (Copyright © 2023. Published by Elsevier Inc.)

Low molecular weight iron (LMW-Fe)-mediated oxidative stress from heme degradation may reduce beef water-holding capacity (WHC). However, the underlying mechanism of heme degradation is still unknown. In the present study, we assessed the WHC, tissue morphology, reactive oxygen species (ROS), apoptosis, heme oxygenase(HMOX) 1 expression, and ferroptosis characteristics of beef chilled at 4 °C for 6 days. Results showed that water loss increased and WHC decreased during beef storage (P < 0.05). Increased protein and mRNA expression of HMOX1 promoted the decomposition of heme and facilitated the liberation of iron ions (P < 0.05), and excess LMW-Fe was associated with ROS formation, depletion of glutathione, and inhibition of glutathione peroxidase 4 activity (P < 0.05). Muscle tissue showed typical features of ferroptosis, including expression of ferroptosis-related genes, malondialdehyde accumulation, and structural damage to mitochondria (P < 0.05). It was also found that HMOX1 and the heme pathway-mediated ferroptosis were associated with structural changes in myofibrils and reduced WHC in chilled beef., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Inosine monophosphate (IMP) is an indicator of meat taste, and the molecular mechanism underlying IMP deposition in muscle tissues is important to developing superior poultry breeds. The aim of this study was to identify the key proteins regulating IMP deposition in different muscle groups of 180-day-old Jingyuan chickens (Hen) using a proteomics-based approach. We identified 1,300 proteins in the muscle tissues of Jingyuan chickens, of which 322 were differentially expressed between the breast and leg muscles (129 proteins were highly expressed in breast muscles and 193 proteins were highly expressed in leg muscles). PGM1, PKM2, AK1, AMPD1, and PurH/ATIC were among the differentially expressed proteins (DEPs) involved in the purine metabolism pathway, of which purH was highly expressed in leg muscles, while the others were highly expressed in breast muscles. The proteomics screening results were verified by PRM, qPCR, and western blotting, showing consistency with the proteomics results. Our findings are not only significant in terms of protecting the Jingyuan chicken germplasm resources, but also provide the molecular basis for generating high-quality broiler chicken breeds., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)