Comparative phosphoproteomic provides insights into meat quality differences between slow- and fast-growing broilers

Effects of supplementation with vitamin D3 on growth performance, lipid metabolism and cecal microbiota in broiler chickens

Lower intramuscular fat (IMF) and excessive abdominal fat reduce carcass quality in broilers. The study aimed to investigate the effects of dietary VD3 on growth performance, lipid metabolism and cecal microbiota in broilers over an 84-d feeding experiment. One-day-old male Luhua broilers (210) were randomly assigned to control (basal diet) and VD group (basal diet supplemented with 3,750 IU/kg VD3). Samples were collected after a 12-h fasted feeding on days 28, 56, and 84. Supplementary VD3 significantly enhanced average daily gain (ADG) in broilers aged 57-84 d and 1-84 d, and increased leg muscle rate and fat content in breast and leg muscles and reduced abdominal fat rate of broilers at 84 d. VD3 increased TG and glycogen content in the liver of 28- and 84-d-old broilers, serum TG and VLDL-C content at 56 and 84 d, and TC, HDL-C and LDL-C at 84 d. VD3 increased mRNA expressions of genes related to de novo lipogenesis (DNL) (mTOR, SREBP-1c, FAS and ACC), lipid oxidation (AMPK, PPARα, CPT-1α and ACO) and lipid transport (ApoB and MTTP), and FAS, ACC and CPT1 enzyme activities in the liver. However, mRNA levels of genes involved in DNL and cellular lipid uptake (LPL and FATP1) and LPL activity were decreased in abdominal adipose tissue, and that of genes involved in lipid oxidation and lipolysis (HSL and ATGL) was increased by VD3. LPL and FATP1 expression in breast and leg muscles was increased by VD3. Moreover, VD3 increased the abundance of cecum Bacteroides at 28 and 84 d, Rikenellaceae_RC9_gut_group and Faecalibacterium at 56 and 84 d, and Lachnoclostridium at 84 d. These bacteria were correlated with increased DNL, lipid oxidation and lipid transport in liver, and cellular lipid uptake in muscle, as well as decreased DNL and cellular lipid uptake, and increased lipid oxidation and lipolysis in abdominal adipose tissue. Altogether, supplementary VD3 in basal diet improved growth performance, increased IMF, and reduced abdominal fat rate, which is significant for enhancing feed utilization and improving the carcass quality of broilers. The regulation of VD3 on lipid metabolism could was associated with variation in cecal microbiota composition.

Exploring variances in meat quality between Qingyuan partridge chicken and Cobb broiler: Insights from combined multi-omics analysis

Previously, animal breeding prioritized enhancing key economic traits to improve production efficiency, leading to a gradual difference in meat quality. However, the genetic factors influencing meat quality remain unclear. To identify key genetic pathways contributing to meat quality, native Chinese yellow-feathered chicken (Qingyuan Partridge Chicken, QPC; female, n=10), and commercial chicken broiler (Cobb broiler, CB; female, n=10) were used for meat quality assessment through metabolomics, proteomics, and phosphoproteomics sequencing. The results show that QPC had lower pH (93.12%), shear force (81.46%), cooking loss (69.29%), moisture content (93.24%) and muscle fiber area (46.04%), but higher meat color values (a*(163.65%) and b*(250.27%)), drip loss (146.32%), and intramuscular fat content (382.01%) than CB (p < 0.05). Metabolomic, proteomic, and phosphoproteomic analyses were jointly conducted, revealing significant differences in energy metabolism strategies. Higher glycolytic enzyme activity was observed in QPC (ENO1, GAPDH, GPI, PFKM, PKM, and TPI1, p < 0.05), while more energetic phosphate compounds were stored in CB. CB had higher Na+/K+ Pump protein abundance (SCN4A, LOC107051305, ATP1B4, ATP12A, ATP1A1, and ATP1A2, p < 0.05) and phosphorylation (ATP1A2-Ser662, p < 0.05) and Ca2+ channel protein abundance (ATP2B4, SRL, CACNB1, CACNA1S, CACNA2D1, CAMK2G, LOC107050717 and TNNC2, p < 0.05) than QPC. In QPC, CAMKII autophosphorylation activated downstream protein and increased Ca2+. These results suggest CB is more contractile than QPC, contributing to meat quality between CB and QPC.

Comparative Analysis of Myofiber Characteristics, Shear Force, and Amino Acid Contents in Slow- and Fast-Growing Broilers

Skeletal muscle fiber characteristics are pivotal in assessing meat quality. However, there is currently a lack of research precisely quantifying the total number of myofibers (TNM) of skeletal muscles. This study used Arbor Acres (AA) broilers and Wenchang (WC) chickens to determine the TNM of several skeletal muscles and the meat quality of the pectoralis major muscle (PM). The results showed that the TNMs of the PM in AA males and females were 935,363.64 ± 92,529.28 and 873,983.72 ± 84,511.28, respectively, significantly higher than those in WC (511,468.97 ± 73,460.81 and 475,371.93 ± 70,187.83) at 7 days of age (p < 0.01). In terms of gastrocnemius medialis in AA males and females, we recorded values of 207,551.43 ± 31,639.97 and 177,203.23 ± 28,764.01, showing a significant difference compared to the values observed in WC (146,313.03 ± 29,633.21 and 124,238.9 ± 20,136.95) (p < 0.01). Similarly, the levels of gastrocnemius lateralis exhibited a significant difference between AA and WC (p < 0.01). Furthermore, the essential, umami, and sweet amino acids were found to be significantly higher in WC compared to AA (p < 0.01). These findings offer valuable data and insights for accurately quantifying the TNM in livestock and for the development of further genetic breeding strategies for meat quality.

Characterization of the regulatory network and pathways in duodenum affecting chicken abdominal fat deposition

The excessive accumulation of abdominal fat in chickens has resulted in a reduction in both the feed conversion efficiency and the slaughter yield. To elucidate the regulatory mechanisms and metabolic pathways affecting abdominal fat deposition in the context of broiler breeding, a cohort of 400 Qingyuan partridge chickens with varying abdominal fat deposition was established. Whole transcriptome sequencing analyses were conducted on the duodenum of 20 representative chickens to ascertain the regulatory networks at this vital digestive and absorptive organ. Consequently, 116 differentially expressed genes were identified, exhibiting a trend of increasing or decreasing expression in correlation with the accumulation of abdominal fat. A total of 36 DEmRNAs, 170 DElncRNAs, 92 DEcircRNAs and 88 DEmiRNAs were identified as differentially expressed between chickens with extremely high and low abdominal fat deposition. The functional enrichment analyses demonstrated that the differentially expressed RNA in the duodenum were involved in the regulation of chicken abdominal fat deposition by mediating a series of metabolic pathways, including the Wnt signaling pathway, the PPAR signaling pathway, the Hippo signaling pathway, the FoxO signaling pathway, the MAPK signaling pathway and other signaling pathways that are involved in fatty acid metabolism and degradation. The construction of putative interaction pairs led to the suggestion of two lncRNA-miRNA-mRNA ceRNA networks comprising two mRNAs, two miRNAs, and 29 lncRNAs, as well as two circRNA-lncRNA-miRNA-mRNA ceRNA networks comprising 26 mRNAs, 12 miRNAs, 17 lncRNAs, and nine circRNAs, as core regulatory networks in the duodenum affecting chicken abdominal fat deposition. The aforementioned genes including TMEM150C, REXO1, PIK3C2G, ppp1cb, PARP12, SERPINE2, LRAT, CYP1A1, INSR and APOA4, were proposed as candidate genes, while the miRNAs, including miR-107-y, miR-22-y, miR-25-y, miR-2404-x and miR-16-x, as well as lncRNAs such as ENSGALT00000100291, TCONS_00063508, TCONS_00061201 and TCONS_00079402 were the candidate regulators associated with chicken abdominal fat deposition. The findings of this study provide a theoretical foundation for the molecular mechanisms of mRNAs and non-coding RNAs in duodenal tissues on abdominal fat deposition in chickens.

Integrative multiomics analysis identifies key genes regulating intramuscular fat deposition during development

Intramuscular fat (IMF) content is an important indicator of livestock and poultry meat quality. Enhancing IMF deposition can significantly improve meat quality. Focusing on the core process of IMF deposition, this study used the Jingxing Yellow (JXY) chickens as a model organism and employed multi-omics approaches, including RNA-sequencing (RNA-seq), Whole-genome bisulfite sequencing (WGBS), and metabolomics, to identify the key genes influencing IMF deposition in chickens during development. The results indicated that the contents of triglycerides (TG) and phospholipids (PLIP) exhibited an upward trend. The TG content did not differ significantly between day 1 (D1) and day 7 (D7), but increased significantly after 35 days (D35) of age. The WGBS results revealed that CpG methylation was the predominant methylation type in the breast muscle tissue of JXY chickens. Integrative analysis of RNA-seq and WGBS identified 50 genes, including PLA2G4F, PALMD, PLSCR5, ARHGEF26, LUM, DCN, TNRC6B, CACNA1C, ROBO1, and MBTPS2, whose methylation levels were significantly negatively correlated with their expression levels. In addition, the combined Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differentially-expressed metabolites (DEM) and differentially-expressed genes (DEG) converged on the glycerophospholipid metabolism pathway, which was significantly enriched in DEGs such as PLA2G4F, PLA2G15, LPIN1, MBOAT2, DGKH, AGPAT2, and CHKA, as well as DEM like glycerophosphocholine and phosphocholine. Notably, PLA2G4F was identified as a DEG by DNA methylation, suggesting that PLA2G4F could be a key candidate gene influencing IMF deposition during chicken development. These findings are expected to provide a solid theoretical foundation for improving meat quality through targeted genetic and epigenetic interventions.

Genomic insights into the contribution of de novo lipogenesis to intramuscular fat deposition in chicken

INTRODUCTION

The proportion of animal based foods in daily diet of consumers is constantly increasing, with chicken being highly favored due to its high protein and low fat characteristics. The consumption of chicken around the world is steadily increasing. Intramuscular fat (IMF) is a key indicator affecting meat quality.

OBJECT

High IMF content can contribute to improve the quality of chicken meat. The regulatory mechanism of IMF deposition in chicken is poorly understood, so its complete elucidation is essential to improve chicken meat quality.

METHOD

Here, we performed whole genome resequencing on 516 yellow feather chickens and single-cell RNA sequencing on 3 63-day-old female JXY chickens. In addition, transcriptome sequencing techniques were also performed on breast muscle tissue of JXY chickens at different developmental stages. And 13C isotope tracing technique was applied.

RESULTS

In this study, a large-scale genetic analysis of an IMF-selected population and a control population identified fatty acid synthase (FASN) as a key gene for improving IMF content. Also, contrary to conventional view, de novo lipogenesis (DNL) was deemed to be an important contributor to IMF deposition. As expected, further analyses by isotope tracing and other techniques, confirmed that DNL mainly occurs in myocytes, contributing about 40% of the total fatty acids through the regulation of FASN, using the available FAs as substrates. Additionally, we also identified a relevant causal mutation in the FASN gene with effects on FA composition.

CONCLUSION

These findings contribute to the understanding of fat metabolism in muscle tissue of poultry, and provide the feasible strategy for the production of high-quality chicken meat.

Phosphoproteomic Analysis Indicates Phosphorylated Proteins in Response to Postharvest Blueberries Fruit Softening during Shelf Life

Postharvest blueberry fruit is prone to softening. Protein phosphorylation is an important post-translational modification that was involved in fruit softening. However, little is known about protein phosphorylation in postharvest blueberry fruit softening. The firmness, the apparent morphology, and cell structures of blueberry fruit were changed. As the decay rate of postharvest blueberry fruit increased, the soluble solid and titrable acid contents decreased significantly. Phosphoproteomic sequencing results showed that there were 4100 phosphorylated peptides, 5635 phosphorylated sites, and 1437 phosphorylated proteins and showed significant differences on 0 and 8 d. The GO database and KEGG pathway results indicated that these phosphorylated proteins were mainly involved in "biological process", "molecular function", "plant hormone signal transduction", and "metabolic pathways". Besides, a number of phosphorylated proteins were found in cell wall metabolism, plant hormone signaling, primary metabolism, energy metabolism, membrane and transport, ubiquitination-based proteins, and other metabolisms.

Insights into the evaluation, influential factors and improvement strategies for poultry meat quality: a review

Poultry meat, an essential source of animal protein, requires stringent safety and quality measures to address public health concerns and growing international attention. This review examines both direct and indirect factors that compromise poultry meat quality in intensive farming systems. It highlights the integration of rapid and micro-testing with traditional methods to assess meat safety. The paper advocates for adopting probiotics, prebiotics, and plant extracts to improve poultry meat quality.

Label-free liquid chromatography-mass spectrometry comparison of the breast muscle proteome profiles in two fast-growing broilers

Poultry meat-production is increasing worldwide; leading to the selection of chickens for meat-production that show a fast growth. A label-free quantitative proteomic-approach and Western-blot were applied to investigate the dynamics of muscle protein under rapid growth conditions in two common fast-growing broiler genetic-lines (Ross 508 and AZ Extra Heavy Red-chicken). Muscle exudate from chicken Pectoralis major was used as substrate to unveil the proteome of these genetic-lines. Six-hundred forty-five proteins were identified in total from all samples, and after statistical-analysis 172 proteins were found to be differentially-expressed, clearly distinguishing the two chicken genetic-lines. Several of these differentially-expressed proteins were involved with the proteasome and glycolysis/gluconeogenesis-pathways. Changes in meat-quality traits were also observed, which were reflected in the proteomic-profile. Proteins involved in the ubiquitin-proteasome system were associated with the bigger muscle mass of Ross 508, while phosphoglucomutase 1 was associated with a possible higher capability of AZ Extra Heavy Red-chickens to cope with stressors. This pilot proteomic-approach applied on muscle exudate samples provided key evidence about the pathways and processes underlying these two chicken genetic-lines and their meat-quality parameters. We also identified potential biomarkers that could determine the peculiar production potentials (e.g. breast-growth) of these broilers-lines, which arise from differences in their genetic-backgrounds.

Integrated Lipidomics and Transcriptomics Analyses Reveal Key Regulators of Fat Deposition in Different Adipose Tissues of Geese (Anser cygnoides)

The fat deposition of different adipose tissues is widely recognized as correlated, with distinct effects on meat quality traits and reproductive performance in poultry. In this study, we utilized lipidomics and transcriptomics analyses to investigate the heterogeneity and regulators of intramuscular fat (IMF), abdominal fat (AF), and subcutaneous fat (SF) in geese. Lipidomic profiling revealed 165, 129, and 77 differential lipid molecules (DLMs) between AF vs. IMF, SF vs. IMF, and SF vs. AF, respectively, with 47 common DLMs identified between AF vs. IMF and SF vs. IMF. Transcriptomic analysis identified 3369, 5758, and 131 differentially expressed genes (DEGs) between AF vs. IMF, SF vs. IMF, and SF vs. AF, respectively, with 2510 common DEGs identified between AF vs. IMF and SF vs. IMF. The KEGG results indicate that DLMs were predominantly enriched in glycerophospholipid and glycerolipid metabolism pathways, while DEGs were primarily enriched in metabolic pathways. Pearson correlation analysis identified FABP4, LPL, PLCB1, DSE, and PDE5A as potential factors influencing fat deposition. This study elucidates the heterogeneity and regulatory factors of different adipose tissues in geese, offering new insights for targeted improvements in goose meat quality and production efficiency.

Protein Post-Translational Modifications Based on Proteomics: A Potential Regulatory Role in Animal Science

Genomic studies in animal breeding have provided a wide range of references; however, it is important to note that genes and mRNA alone do not fully capture the complexity of living organisms. Protein post-translational modification, which involves covalent modifications regulated by genetic and environmental factors, serves as a fundamental epigenetic mechanism that modulates protein structure, activity, and function. In this review, we comprehensively summarize various phosphorylation and acylation modifications on metabolic enzymes relevant to energy metabolism in animals, including acetylation, succinylation, crotonylation, β-hydroxybutylation, acetoacetylation, and lactylation. It is worth noting that research on animal energy metabolism and modification regulation lags behind the demands for growth and development in animal breeding compared to human studies. Therefore, this review provides a novel research perspective by exploring unreported types of modifications in livestock based on relevant findings from human or animal models.

Quantitative Phosphoproteomics Analysis Reveals the Protective Mechanism of Chlorogenic Acid on Immunologically Stressed Broiler Meat Quality

Modern poultry production is stressful for the birds, and this stress is recognized as a major cause of inferior meat quality. Chlorogenic acid (CGA), a plant phenolic acid, has excellent antioxidant and anti-inflammatory properties. The antioxidant capacity and phosphoproteomics of immunologically stressed broiler breast muscle were assessed to elucidate the mechanism of the beneficial effects of CGA on meat quality. Dietary CGA decreased drip and cooking loss, postmortem pH and antioxidant capacity of breast muscle from stressed broilers, and increased MyHC-I mRNA levels. Quantitative phosphoproteomics revealed that CGA supplementation downregulated the phosphorylation of myofibrillar proteins, glycolytic enzymes, and endoplasmic reticulum proteins involved in homeostasis, which contributed to improving the meat quality of broilers. Moreover, 14 phosphorylation sites (e.g., P13538-Ser1236 and F1NN63-Ser117) in 13 phosphoproteins were identified as key regulators of processes related to broiler meat quality. Together, these findings provide novel regulatory targets and nutritional strategies for improving the stressed broiler meat quality.

Xanthatin suppresses pancreatic cancer cell growth via the ROS/RBL1 signaling pathway: In vitro and in vivo insights

BACKGROUND

As a malignant digestive system tumor, pancreatic cancer has a high mortality rate. Xanthatin is a sesquiterpene lactone monomer compound purified from the traditional Chinese herb Xanthium strumarium L. It has been reported that Xanthatin exhibits inhibitory effects on various cancer cells in retinoblastoma, glioma, hepatoma, colon cancer, lung cancer, as well as breast cancer. However, in pancreatic cancer cells, only one report exists on the suppression of Prostaglandin E2 synthesis and the induction of caspase 3/7 activation in Xanthatin-treated MIA PaCa-2 cells, while systematic in vitro and in vivo investigations and related mechanisms have yet to be explored.

PURPOSE

This research aims to explore the in vitro and in vivo effects of Xanthatin on pancreatic cancer and its molecular mechanisms.

METHODS

The anticancer effects and mechanisms of Xanthatin on pancreatic cancer cells were assessed through employing cell counting kit-8 (CCK-8) assay, lactate dehydrogenase (LDH) assay, carboxyfluorescein diacetate succinimidyl ester (CFDA SE) cell proliferation assay, colony formation assay, wound healing assay, transwell assay, Annexin V-FITC/propidium iodide (PI) dual staining, Hoechst nuclear staining, Western blot analysis, phosphoproteomics, and reactive oxygen species (ROS) measurement. The in vivo anticancer effects of Xanthatin on pancreatic cancer cells were studied using a nude mouse model.

RESULTS

The present study showed that Xanthatin can prevent the proliferation and metastasis of pancreatic cancer cells and trigger the exposure of phosphatidylserine (PS), chromatin condensation, and caspase activation, thereby inducing apoptosis. Phosphoproteomic analysis indicated that Xanthatin inhibits the phosphorylation of the proliferation-associated protein RBL1, and oxidative stress can lead to RBL1 dephosphorylation. Further investigation revealed that Xanthatin significantly upregulates ROS levels in pancreatic cancer cells, and the antioxidant N-acetylcysteine (NAC) can reverse Xanthatin-induced cell proliferation inhibition and apoptosis. In addition, Xanthatin can suppress pancreatic cancer cell growth in a xenograft nude mouse model with low toxicity to the mice.

CONCLUSION

Xanthatin may inhibit the proliferation of pancreatic cancer cells and trigger apoptosis through the ROS/RBL1 signaling pathway.

The ionome and proteome landscape of aging in laying hens and relation to egg white quality

The ionome is essential for maintaining body function and health status by participating in diverse key biological processes. Nevertheless, the distribution and utilization of ionome among different organs and how aging impacts the ionome leading to a decline in egg white quality remain unknown. Thus, we used inductively coupled plasma mass spectrometry (ICP-MS) to analyze 35 elements and their isotopic contents in eight organs of laying hens at 35, 72, and 100 weeks. Moreover, the magnum proteome, amino acids in egg white, and egg white quality were analyzed in laying hens at three different ages using 4D proteomics techniques, an amino acid analyzer, and an egg quality analyzer. Across the organs, we identified varying distribution patterns among macroelements (Mg24, Ca43/44, K39, and P31), transition metals (Zn64/66, Cu63/65, Fe56/57, and Mn55), and toxic elements (Pb208, Ba137, and Sr86). We observed an organ-specific aging pattern characterized by the accumulation of toxic elements (Pb208, Ba137, and Sr86) and calcification in the small intestine. Additionally, a decrease in the utilization of essential trace elements selenium (Se78/82) and manganese (Mn55) was noted in the oviduct. By analyzing ionome in tandem with egg quality, egg white amino acids, and proteome, we unveiled that the reduction of selenium and manganese concentrations in the magnum during the aging process affected amino acid metabolism, particularly tryptophan metabolism, thereby inhibiting the amino acid synthesis in the magnum. Furthermore, it accelerated the senescence of magnum cells through necroptosis activation, leading to a decline in the albumen secretion function of the magnum and subsequently reducing egg white quality. Overall, this study provides insights into the evolution of 35 elements and their isotopes across 8 organs of laying hens with age. It also reveals the elemental composition, interactions, and utilization patterns of these organs, as well as their correlation with egg white quality. The present study highlights the significance of ionome and offers a comprehensive perspective on the selection of ionome for regulating the aging of laying hens.

Evaluation of Carcass Attributes and Physical, Chemical, and Qualitative Characteristics of Breast Meat of Broiler Chickens Fed on Pulicaria jaubertii Powder

Pulicaria jaubertii (PJ) is a medicinal plant used as a synthetic antioxidant and as a traditional medicine due to its bioactive compounds. The objective of this study was to investigate the effects of PJ on carcass traits and breast meat quality parameters of broiler chickens. Two hundred and forty male broilers (1 day old) were divided into four groups (0, 3, 6, and 9 g of PJ/kg of basal diet). Performance indicators were evaluated during the feeding stages, and carcass characteristics and physiochemical and qualitative parameters of breast meat were measured at 36 days old. The results showed that PJ improved performance parameters such as weight gain, feed conversion ratio, and production efficiency index (p < 0.05) in the finishing stage. The diets supplemented with PJ were associated with better carcass characteristics (p < 0.05), but some body parts, such as legs (6 and 9 g PJ) and backs (3-9 g PJ) decreased (p < 0.05). Temperature and initial pH were decreased by PJ (p < 0.05). Meat color was not affected by PJ (p > 0.05), although the yellowness and saturation index were lower at 9 g PJ. Total saturated fatty acid content was higher at 3 g PJ, while total polyunsaturated fatty acids and unsaturated to saturated fatty acid ratio were lower at 3 and 6 g PJ (p < 0.05). Total monounsaturated fatty acid content increased at 6 and 9 g PJ. Omega-6 fatty acids and the ratio of omega-6 to omega-3 were lower at 3 g PJ. PJ resulted in higher weight loss on cooking (6 and 9 g PJ) and shear force (3-9 g PJ). In conclusion, PJ had a positive influence on performance, carcass characteristics, and fatty acid profile, and some meat quality traits were generally improved by PJ, but knowledge of its mode of action is still limited and therefore requires further investigation.

Effects of Gum Arabic (Acacia senegal) Powder on Characteristics of Carcass and Breast Meat Quality Parameters in Male Broiler Chickens

Gum Arabic, one of the soluble fibers, is considered a source of natural prebiotics that can be fermented by the activity of the intestinal microbiota and, therefore, may have a positive effect on the performance, carcass characteristics, and meat quality of broilers. Therefore, the objective of this study was to investigate the effects of gum Arabic on performance, carcass characteristics, physicochemical properties, and quality of broiler breast meat. Six dietary treatments (T1-T5) with a basal diet (CON) containing 0.12%, 0.25%, 0.5%, 0.75%, and 1.0% gum Arabic, respectively. A total of 432 one-day-old male broiler chickens were conducted for 35 days. Performance and carcass characteristics, as well as physical, qualitative, and chemical indicators of breast meat, were evaluated. The results showed that the treatments improved overall performance (p < 0.05), such as body weight, weight gain, feed conversion ratio, and performance index, except for feed intake, which was lower at T1, T2, and T5 than at CON. Carcass characteristics, body components, and breast meat color or initial pH were not affected by dietary treatments (p > 0.05), but ultimate pH (T1 and T2) and color lightness were comparatively lower, and color change (T2-T3) was comparatively higher. Cooking water loss (T2-T4) and shear force (T1-T5) were higher in the treatments. Cohesiveness and resilience were higher in T2, while gumminess and chewiness were lower in T4 and T5. T1 breast meat had higher crude protein content and lower crude fat content, but the other chemical compositions were not affected by the treatments. Some fatty acids in the breast meat were more affected by treatments compared to CON. In conclusion, the present findings showed that gum Arabic (0.12% to 0.75%) has favorable effects on growth performance and some quality indicators of breast meat (such as cooking water loss, shear force, protein, and fat content), especially at the level of 0.12% with no alterations on the carcass characteristics and body components or physical indicators of breast meat.

Effects of muscle-specific oxidative stress on protein phosphorylation and its relationship with mitochondrial dysfunction, muscle oxidation, and apoptosis

This study aimed to investigate the effects of muscle-specific oxidative stress on phosphorylation and its relationship with mitochondrial dysfunction, muscle oxidation, and apoptosis of porcine PM (psoas major) and LL (longissimus lumborum) during the first 24 h postmortem. The global phosphorylation level decreased and the mitochondrial dysfunction, oxidation level, and apoptosis increased significantly at 12 h postmortem compared with 2 h postmortem, suggesting that lower phosphorylation level was related to more mitochondrial dysfunction and apoptosis during the early postmortem, regardless of muscle type. PM exhibited a higher global phosphorylation level but showed greater mitochondrial dysfunction, oxidation level, and apoptosis than LL, regardless of aging time. The increased mitochondrial dysfunction and oxidative stress accelerated apoptosis, but their relationship with phosphorylation was different in various muscle types at different aging times. These findings provide insight regarding the roles of coordinated regulation of phosphorylation and apoptosis in development of quality of different muscles.

Characterization of meat quality traits, fatty acids and volatile compounds in Hu and Tan sheep

Sheep breed has a major influence on characteristics of meat quality and intramuscular fat (IMF), however, studies into the relationship between sheep breed and meat quality traits rarely consider the large variation in IMF within breed. In this study, groups of 176 Hu and 76 Tan male sheep were established, weaned at 56 days old, with similar weights, and representative samples were selected based on the distribution of IMF in each population, to investigate variations in meat quality, IMF and volatile compound profiles between breeds. Significant differences were observed in drip loss, shear force, cooking loss, and color coordinates between Hu and Tan sheep (p < 0.01). The IMF content and the predominate unsaturated fatty acids, oleic and cis, cis-linoleic acids, were similar. Eighteen out of 53 volatile compounds were identified as important odor contributors. Of these 18 odor-active volatile compounds, no significant concentration differences were detected between breeds. In another 35 volatile compounds, γ-nonalactone was lower in Tan sheep relative to Hu sheep (p < 0.05). In summary, Tan sheep exhibited lower drip loss, higher shear force values, and redder color, had less saturated fatty acids, and contained less γ-nonalactone against Hu sheep. These findings improve understanding of aroma differences between Hu and Tan sheep meat. Graphical Abstract.

Phosphoproteomic analysis identifies differentially expressed phosphorylation sites that affect muscle fiber type in pigs

Skeletal muscle of livestock is composed of both fast- and slow-twitch muscle fibers, which are key factors in their meat quality. However, the role of protein phosphorylation in muscle fiber type is not completely understood. Here, a fast-twitch (biceps femoris, BF) and slow-twitch (soleus, SOL) muscle tissue sample was collected from three male offspring of Duroc and Meishan pigs. We demonstrate that the meat quality of SOL muscle is significantly better than that of BF muscle. We further used phosphoproteomic profiling of BF and SOL muscles to identify differences between these muscle types. A total of 2,327 phosphorylation sites from 770 phosphoproteins were identified. Among these sites, 287 differentially expressed phosphorylation sites (DEPSs) were identified between BF and SOL. GO and KEGG enrichment analysis of proteins containing DEPSs showed that these phosphorylated proteins were enriched in the glycolytic process GO term and the AMPK signaling pathway. A protein-protein interaction (PPI) analysis reveals that these phosphorylated proteins interact with each other to regulate the transformation of muscle fiber type. These analyses reveal that protein phosphorylation modifications are involved in porcine skeletal muscle fiber type transformation. This study provides new insights into the molecular mechanisms by which protein phosphorylation regulates muscle fiber type transformation and meat quality in pigs.

Identification of candidate genomic regions for thermogelled egg yolk traits based on a genome-wide association study

Egg yolk texture is an important indicator for evaluating egg yolk quality. Genetic markers associated with economic traits predict genomes and facilitate mining for potential genes. Numerous genome-wide association studies have been conducted on egg traits. However, studies on the genetic basis of thermogelled yolk texture are still lacking. The aim of the present study was to find significant single nucleotide polymorphism (SNP) sites and candidate genes related to thermogelled yolk texture in Hetian Dahei chicken (HTHD) flocks that can be used as genetic markers. Five traits, including hardness, cohesiveness, gumminess, chewiness, and resilience, had low heritability (0.044-0.078). Ten genes, including U6, FSHR, PKDCC, SLC7A11, TIMM9, ARID4A, PSMA3, ACTR10, EML4, and SLC35F4 may control the hardness of the thermogelled egg yolks. In addition, 12 SNPs associated with cohesiveness were identified. RELCH located on GGA2 participates in cholesterol transport. The candidate gene LRRK2, which is associated with gumminess, influences the concentrations of very low-density lipoprotein in blood. Eight SNPs associated with resilience were identified, mainly on GGA3 and GCA28. In total, 208 SNPs associated with chewiness were identified, and 159 candidate genes, which were mainly involved in proteasome-mediated ubiquitin-dependent protein catabolic process, negative regulation of transport, lipid droplet organization, and vehicle docking involved in exocytosis, were found near these regions. Thermogel egg yolk texture is a complex phenotype controlled by multiple genes. Based on heritability assays and GWAS results, there is a genetic basis for the texture of thermogelled egg yolks. We identified a series of SNPs associated with yolk texture and candidate genes. Our result provides a theoretical basis for breeding high-quality egg yolk using molecular marker-assisted selection and could facilitate the development of novel traits.

A comparative study of vacuum tumbling and immersion marination on quality, microstructure, and protein changes of Xueshan chicken

Marination is a common technology in meat processing with advantages of enhancing tenderness, water retention, and overall quality. This study was conducted to investigate the effect of vacuum tumbling and immersion marination on meat quality, microstructure, water mobility, protein changes, and denaturation of Xueshan chicken. Results showed that vacuum tumbling significantly increased the marinating rate of chicken, tenderness, meat texture, and water retention. Meanwhile, vacuum tumbling decreased total sulfhydryl content alongside an increased protein surface hydrophobicity and free sulfhydryl content, indicating that vacuum tumbling elevated the degree of protein denaturation. Further, the peak area corresponding to the relaxation time T22 after vacuum tumbling was significantly higher than that of immersion marination, suggesting that the stability of the immobilized water of chicken was reduced by vacuum tumbling. Compared to immersion marination, vacuum tumbling improved myofibril fragmentation index (MFI) presenting fewer myofibrillar protein bands in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel and more damaged muscular cells. Overall, vacuum tumbling could improve the marination absorptivity, protein degradation, and denaturation, resulting in changes in myofibril structure and meat quality of Xueshan chicken.

SLC16A7 Promotes Triglyceride Deposition by De Novo Lipogenesis in Chicken Muscle Tissue

Triglyceride (TG) content in chicken muscle tissue signifies intramuscular fat (IMF) content, which is important for improving meat quality. However, the genetic basis of TG deposition in chicken is still unclear. Using 520 chickens from an artificially selected line with significantly increased IMF content and a control line, a genome-wide association study (GWAS) with TG content reports a region of 802 Kb located in chromosome 1. The XP-EHH and gene expression analysis together reveal that the solute carrier family 16 member A7 (SLC16A7) gene is the key candidate gene associated with TG content in chicken muscle tissue. Furthermore, the weighted gene co-expression network analysis (WGCNA) confirmed the regulatory effects of SLC16A7 on promoting TG deposition by de novo lipogenesis (DNL). Functional verification of SLC16A7 in vitro also supports this view, and reveals that this effect mainly occurs in myocytes. Our data highlight a potential IMF deposition pathway by DNL, induced by SLC16A7 in chicken myocytes. These findings will improve the understanding of IMF regulation in chicken and guide the formulation of breeding strategies for high-quality chicken.

Phosphoproteome Analysis Using Two-Dimensional Electrophoresis Coupled with Chemical Dephosphorylation

Protein phosphorylation is a reversible post-translational modification (PTM) with major regulatory roles in many cellular processes. However, the analysis of phosphoproteins remains the most challenging barrier in the prevailing proteome research. Recent technological advances in two-dimensional electrophoresis (2-DE) coupled to mass spectrometry (MS) have enabled the identification, characterization, and quantification of protein phosphorylation on a global scale. Most research on phosphoproteins with 2-DE has been conducted using phosphostains. Nevertheless, low-abundant and low-phosphorylated phosphoproteins are not necessarily detected using phosphostains and/or MS. In this study, we report a comparative analysis of 2-DE phosphoproteome profiles using Pro-Q Diamond phosphoprotein stain (Pro-Q DPS) and chemical dephosphorylation of proteins with HF-P from longissimus thoracis (LT) muscle samples of the Rubia Gallega cattle breed. We found statistically significant differences in the number of identified phosphoproteins between methods. More specifically, we found a three-fold increase in phosphoprotein detection with the HF-P method. Unlike Pro-Q DPS, phosphoprotein spots with low volume and phosphorylation rate were identified by HF-P technique. This is the first approach to assess meat phosphoproteome maps using HF-P at a global scale. The results open a new window for 2-DE gel-based phosphoproteome analysis.