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:The aim of this study was to identify genes involved in the variation of the muscle glycogen content at death (estimated through the glycolytic potential, GP), a determining factor of meat quality in chicken. Gene expression profiles of Pectoralis major muscle were established using microarrays. We compared Fat and Lean chickens issued from two lines divergently selected for abdominal fatness and also differed for muscle GP. A total of 197 genes were differentially expressed between Fat and Lean pure chickens. Several of these genes were validated by qRT-PCR. For the genes with human orthologs, annotation analyses were performed and mainly revealed pathways involved carbohydrate, fatty-acid, and protein metabolism. The relationship between gene expression and meat quality has to now be validated by further e-QTL studies on the F2 population. 8 samples from Fat chickens were compared to 8 samples from Lean chickens, 4 of these were dye-swapped.
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:The aim of this study was to identify genes involved in the variation of the muscle glycogen content at death (estimated through the glycolytic potential, GP), a determining factor of meat quality in chicken. Gene expression profiles of Pectoralis major muscle were established using microarrays. We compared Fat and Lean chickens issued from two lines divergently selected for abdominal fatness and also differed for muscle GP. A total of 197 genes were differentially expressed between Fat and Lean pure chickens. Several of these genes were validated by qRT-PCR. For the genes with human orthologs, annotation analyses were performed and mainly revealed pathways involved carbohydrate, fatty-acid, and protein metabolism. The relationship between gene expression and meat quality has to now be validated by further e-QTL studies on the F2 population.
Project description:Chronological age is one of the important factors influencing muscle development and meat quality in chickens. To evaluate the protein expression profiles during skeletal muscle development, we performed a tandem mass tag (TMT)-based quantitative proteomic strategy in pectoralis major (breast muscle) of Beijing-You chicken (BYC) at the age of 90, 120 and 150 days. A total of 1,413 proteins in chicken breast muscle and 197 of them were differentially expressed (fold change ≥ 1.2 or ≤ 0.8333 and p < 0.05). There were 110 up- and 71 down-regulated proteins in 120 d vs. 90 d group, 13 up- and 10 down-regulated proteins in 150 d vs. 120 d group. The proteomic profiles of BYC at 120 d were very similar to those at 150 d and highly different from those at 90 d, suggesting that 120 d might be an important chronological age for BYC. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these differentially expressed proteins were mainly involved in the pathway of glycolysis/gluconeogenesis, adrenergic signaling in cardiomyocytes, focal adhesion, oocyte meiosis and phagosome. Protein expression analysis indicated that the differences in muscle growth rate between ages were regulated by proteins such as LDHA and ENO3, whereas ATP2A1 and HSP70 were associated with water-holding capacity (WHC), and PPP1CB and COL1A2 were suggested to lie in the role of intramuscular fat (IMF) deposition. In addition, RACK1 was thought to be crucial for the sexual maturation during chicken development. Furthermore, some DEPs were quantified using parallel reaction monitoring (PRM) to validate the results from TMT analysis. Overall, the present work could strengthen our view of the temporal expression profile during development and identify novel biomarkers for genetic breeding of chickens.
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.
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:Abstract: Atmospheric ammonia is a common problem in poultry industry. High concentrations of aerial ammonia cause great harm to broilers' health and production. For the consideration of human health, the limit exposure concentration of ammonia in houses is set at 25 ppm. Previous reports have shown that 25 ppm is still detrimental to livestock, especially the gastrointestinal tract and respiratory tract, but the negative relationship between ammonia exposure and the tissue of breast muscle of broilers is still unknown. In the present study, 25 ppm ammonia in poultry houses was found to lower slaughter performance and breast yield. Then, high-throughput RNA sequencing was utilized to identify differentially expressed genes in breast muscle of broiler chickens exposed to high (25 ppm) or low (3 ppm) levels of atmospheric ammonia. The transcriptome analysis showed that 163 genes (fold change â?¥ 2 or â?¤ 0.5; P-value < 0.05) were differentially expressed between Ammonia25 (treatment group) and Ammonia3 (control group), including 96 down-regulated and 67 up-regulated genes. qRT-PCR analysis validated the transcriptomic results of RNA sequencing. Gene Ontology (GO) functional annotation analysis revealed potential genes, processes and pathways with putative involvement in growth and development inhibition of breast muscle in broilers caused by aerial ammonia exposure. This study facilitates understanding of the genetic architecture of the chicken breast muscle transcriptome, and has identified candidate genes for breast muscle response to atmospheric ammonia exposure. Breast muscle mRNA profiles of 42-day old Arbor Acres male broilers exposed to 3 ppm (Ammonia3) and 25 ppm (Ammonia25) concentrations of atmospheric ammonia were generated by RNA sequencing, in duplicate, using Illumina HiSeq2000.
Project description:Abstract: Atmospheric ammonia is a common problem in poultry industry. High concentrations of aerial ammonia cause great harm to broilers' health and production. For the consideration of human health, the limit exposure concentration of ammonia in houses is set at 25 ppm. Previous reports have shown that 25 ppm is still detrimental to livestock, especially the gastrointestinal tract and respiratory tract, but the negative relationship between ammonia exposure and the tissue of breast muscle of broilers is still unknown. In the present study, 25 ppm ammonia in poultry houses was found to lower slaughter performance and breast yield. Then, high-throughput RNA sequencing was utilized to identify differentially expressed genes in breast muscle of broiler chickens exposed to high (25 ppm) or low (3 ppm) levels of atmospheric ammonia. The transcriptome analysis showed that 163 genes (fold change ≥ 2 or ≤ 0.5; P-value < 0.05) were differentially expressed between Ammonia25 (treatment group) and Ammonia3 (control group), including 96 down-regulated and 67 up-regulated genes. qRT-PCR analysis validated the transcriptomic results of RNA sequencing. Gene Ontology (GO) functional annotation analysis revealed potential genes, processes and pathways with putative involvement in growth and development inhibition of breast muscle in broilers caused by aerial ammonia exposure. This study facilitates understanding of the genetic architecture of the chicken breast muscle transcriptome, and has identified candidate genes for breast muscle response to atmospheric ammonia exposure.
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).