Project description:The processing ability of chicken meat is highly related to its ultimate pH (pHu), which is mainly determined by the amount of glycogen in the muscle at death. The molecular mechanisms involved in variations of those traits for chicken remain to be fully described. For that purpose, two chicken lines were divergently selected on breast meat pHu, i.e. the pHu- and the pHu+ lines. In this study, Chicken Genome Arrays (60 K) were used to compare muscle gene expression profiles of chickens from both lines. The final goal of this experiment is to identify biomarkers of low and high-pHu chicken meat. This study was supported by INRA and the French Ministry of Agriculture through the RFI CASDAR #1309 OPTIVIANDE.
Project description:Improvement of feed efficiency would increase profitability of the poultry industries by decreasing the amount of feed required for production. Korat (KR) chicken is a new alternative meat-type chicken breed which its meat is recognized for its high protein, low fat and low purine content, whereas its low feed efficiency leads to high cost of production. Deeper understanding on how feed efficiency influences meat quality is poorly elucidated. To fulfill deeper understand molecular key that point the variation in feed efficiency and meat quality, the aim of this study was to investigate molecular pathways and genes involved in feed efficiency and meat quality in thigh of slow-growing KR chicken. A total of 75 males KR chicken were reared in individual cage until 10 weeks of age. Individual feed intake and body weight were collected weekly to calculate Feed Conversion Ratio (FCR) and Residual Feed Intake (RFI). Meat quality parameters were measured in thigh muscles such as ultimate pH (pHu), water-holding capacity (WHC), drip loss (DL), nucleotides content and several biomolecules (amide, …). Base on extreme values of FCR at 10 weeks of ages, 12 birds from the high FCR group (HFCR) and 9 birds from the low FCR group (LFCR) were selected for investigating their transcriptome using an 8×60K Agilent chicken microarray. In addition, a weighted gene coexpression network analysis was performed to detect the relationship between modules of co-expressed genes and feed efficiency, meat quality in thigh muscle. The result in this study indicated that selection on feed efficiency (FCR, RFI) would affect flavor precursor, lipid and protein content in thigh muscle. Based on WGCNA and functional enrichment analysis, results suggested that the key molecular pathways relate to FCR, RFI and meat quality (WHC, DL, IMP, AMP and inosine) in thigh muscle were the pathways of regulation of biological process, biological regulation and regulation of metabolic. Moreover, we revealed four genes there are assembly competence domain (ACD) gene, baculoviral IAP repeat containing 5 (BIRC5) gene, cytochrome c oxidase assembly factor 3 (COA3) gene and myosin light chain 9 (MYL9) gene that might be biomarker gene in feed efficiency and meat quality in thigh muscle. The hypothesis of the current study was alteration feed efficiency in slow-growing chicken will impact meat quality especially in term of texture and flavor.
Project description:In the modern chicken industry, fast-growing broilers have undergone strong artificial selection for muscle growth, which has led to remarkable phenotypic variations compared with slow-growing chickens. However, the molecular mechanism underlying these phenotypes differences remains unknown. In this study, a systematic identification of candidate genes and new pathways related to myofiber development and composition in chicken Soleus muscle has been made using gene expression profiles of two distinct breeds: Qingyuan partridge (QY), a slow-growing Chinese breed possessing high meat quality and Cobb 500 (CB), a commercial fast-growing broiler line. Agilent cDNA microarray analyses were conducted to determine gene expression profiles of soleus and extensor digitorum longus muscle sampled at sexual maturity age of QY (112 d) and CB (42 d).
Project description:Since the effect of selection for better feed efficiency on meat characteristics is largely unknown. Thus, the aim of this study was to identify key proteins and pathways regulating both FE traits and meat characteristics. At ten weeks of age, thigh muscle samples from six birds (three with high FCR and three with low FCR value) were selected, and their proteomes were investigated using a label-free proteomic method. Weighted gene co-expression network analysis (WGCNA) was used to screen the key protein modules and pathways. We found that glycolysis/gluconeogenesis, metabolic pathway, carbon metabolism, biosynthesis of amino acids, pyruvate metabolism, and protein processing in endoplasmic reticulum play a key role underlying these two traits. Thus, selection practices for KR should simultaneously consider both trait groups to maintain the high meat quality of slow-growing chicken while improving FE.
Project description:The egg teeth of chicken of the developmental stage 36 according to Hamburger and Hamilton (about 10 days of egg incubation at 37 °C) were sampled to investigate the protein composition of the egg tooth.
Project description:Carnosine is a bioactive food component with several potential health benefits for humans due to its physiological functions. Dietary supplementation with β-alanine or L-histidine can increase the carnosine content of skeletal muscles in chickens. Dietary supplementation with β-alanine or L-histidine has produced a slow-growing chicken variety with high carnosine content in the breast meat; however, the supplementation with L-histidine alone softens the meat toughness, which may affect consumers’ willingness to buy the meat. Gene expression is a key factor that influences meat quality. Understanding the molecular mechanisms that affect carnosine content and meat toughness would allow the production of more value-added slow-growing chickens. We compared global gene expression in chicken breast muscles with differing carnosine contents and meat toughness produced through dietary supplementation with β-alanine or L-histidine. We identified differentially expressed genes involved in regulating myosin, collagen, intramuscular fat, and calpain—factors that may affect meat tenderness. Pathway enrichment analysis indicated that the insulin-related and adipocytokine signaling pathways were altered by dietary supplementation with β-alanine or L-histidine. These data will be useful for future studies on carnosine content and meat toughness in slow-growing chickens.
Project description:<p><strong>BACKGROUND:</strong> Chicken meat has become a major source of protein for human consumption. However, the quality of the meat is not yet under control, especially since pH values that are too low or too high are often observed. In an attempt to get a better understanding of the genetic and biochemical determinants of the ultimate pH, two genetic lines of broilers were divergently selected for low (pHu−) or high (pHu+) breast meat pHu. In this study, the serum lipidome of 17-day-old broilers from both lines was screened for pHu markers using liquid-chromatography coupled with mass spectrometry (LC-HRMS).</p><p><strong>RESULTS:</strong> A total of 185 lipids belonging to 4 groups (glycerolipids, glycerophospholipids, sterols, sphingolipids) were identified in the sera of 268 broilers from the pHu lines by targeted lipidomics. The glycerolipids, which are involved in energy storage, were in higher concentration in the blood of pHu− birds. The glycerophospholipids (phosphatidylcholines, phosphatidylethanolamines) with long and polyunsaturated acyl chains were more abundant in pHu+ than in pHu− while the lysophosphatidylcholines and lysophosphatidylethanolamines, known to be associated with starch, were observed in higher quantity in the serum of the pHu− line. Finally, the concentration of the sterols and the ceramides, belonging to the sphingolipids class, were higher in the pHu+ and pHu−, respectively. Furthermore, orthogonal partial least-squares analyses highlighted a set of 68 lipids explaining 77% of the differences between the two broilers lines (R2Y = 0.77, Q2 = 0.67). Among these lipids, a subset of 40 predictors of the pHu value was identified with a Root Mean Squared Error of Estimation of 0.18 pH unit (R2Y = 0.69 and Q2 = 0.62). The predictive model of the pHu value was externally validated on 68 birds with a Root Mean Squared Error of Prediction of 0.25 pH unit.</p><p><strong>CONCLUSION:</strong> The sets of molecules identified will be useful for a better understanding of relationship between serum lipid profile and meat quality, and will contribute to define easily accessible pHu biomarkers on live birds that could be useful in genetic selection.</p>
Project description:Optimization of broiler chicken breast muscle protein accretion is key for the efficient production of poultry meat, whose demand is steadily increasing. In a context where antimicrobial growth promoters use is being restricted, it is important to find alternatives as well as to characterize the effect of immunological stress on broiler chicken growth. Despite of its importance, research on broiler chicken muscle protein dynamics has been mostly limited to the study of mixed protein turnover. The present study aims to characterize the effect of a bacterial challenge and the feed supplementation of a citrus and a cucumber extract on broiler chicken individual breast muscle proteins fractional synthesis rates (FSR) using a recently developed dynamic proteomics pipeline. 21 day-old broiler chickens were administered a single 2H2O dose before being culled at different timepoints. A total of 60 breast muscle protein extracts from five experimental groups (Unchallenged, Challenged, Control Diet, Diet 1 and Diet 2) were analyzed using a DDA proteomics approach. Proteomics data was filtered in order to reliably calculate multiple proteins FSR making use of a newly developed bioinformatics pipeline. Broiler breast muscle proteins FSR uniformly decreased following a bacterial challenge, this change was judged significant for 15 individual proteins, the two major functional clusters identified as well as for mixed breast muscle protein. Citrus or cucumber extract feed supplementation did not show any effect on the breast muscle protein FSR of immunologically challenged broilers. The present study has identified potential predictive markers of breast muscle growth and provided new information on broiler chicken breast muscle protein turnover which could be essential for improving the efficiency of broiler chicken meat production.