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: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:Background: High concentrations of atmospheric ammonia are one of the key environmental stressors affecting broiler production performance, which causes remarkable economic losses as well as potential welfare problems of the broiler industry. Previous reports have demonstrated that high levels of ammonia can alter body fat distribution and meat quality of broilers. However, the molecular mechanisms and metabolic pathways in breast muscle altered by high concentrations of ambient ammonia exposure on broilers are still unknown. Results: This study utilized RNA-Seq to compare the transcriptomes of breast muscles to identify differentially enriched genes in broilers exposed to high or low concentrations of atmospheric ammonia. A total of 267 promising candidate genes were identified by differential expression analysis, among which 67 genes were up-regulated and 189 genes were down-regulated. Bioinformatics analysis suggested that the up and down-regulated genes were involved in the following two categories of cellular pathways and metabolisms: Steroid biosynthesis (gga00100) and peroxisome proliferator-activated receptor (PPAR) signaling pathway (gga03320), which both participate in the lipid metabolism processes. Conclusions: This study suggests that longtime exposure to high concentrations of aerial ammonia can change fat content in breast muscle, meat quality and palatability via altering expression levels of genes participating in important lipid metabolism pathways. This study maybe provides new information that could be used for genetic breeding and nutritional intervention in production practice of broilers industry in the future.
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:We report the genome-wide DNA methylation mapping of chicken by methylated DNA immunoprecipitation following by highthroughput sequencing, and the gene expression profile of chicken by RNA-seq. For meDIP-seq, about 17,202,074 to 27,501,760 reads were generated for the tissue and liver tissues of the red jungle fowl and the avian broiler each. We found that compared with the red jungle fowl, DNA methylation in muscle tissue of the avian broiler, showed dramatically decline on a genome-wide scale. Furthermore, the length of the highly methylated regions (HMRs) has become shorter in the avian broiler, which has suffered intense artificial selection. In addition to the global changes in DNA methylation, transcriptome-wide analysis of the two breeds of chicken revealed that the patterns of gene expression in the domestic chicken have undergone a specific bias towards a pattern that is more suited to human-made environments with variable expression in certain gene functions, such as immune response and fatty acid metabolism. Our results demonstrated a potential role of epigenetic modification in animal domestication besides the genetic variations. Examination of whole genome DNA methylation status in liver and muscle of two chicken breeds.
Project description:We report the genome-wide DNA methylation mapping of chicken by methylated DNA immunoprecipitation following by highthroughput sequencing, and the gene expression profile of chicken by RNA-seq. For meDIP-seq, about 17,202,074 to 27,501,760 reads were generated for the tissue and liver tissues of the red jungle fowl and the avian broiler each. We found that compared with the red jungle fowl, DNA methylation in muscle tissue of the avian broiler, showed dramatically decline on a genome-wide scale. Furthermore, the length of the highly methylated regions (HMRs) has become shorter in the avian broiler, which has suffered intense artificial selection. In addition to the global changes in DNA methylation, transcriptome-wide analysis of the two breeds of chicken revealed that the patterns of gene expression in the domestic chicken have undergone a specific bias towards a pattern that is more suited to human-made environments with variable expression in certain gene functions, such as immune response and fatty acid metabolism. Our results demonstrated a potential role of epigenetic modification in animal domestication besides the genetic variations. Examination of whole genome gene expression profiles in liver and muscle tissues of two chicken breeds.
Project description:High throughput sequencing technology was used to sequence the transcriptome of breast muscle tissue of control group and test group IV, the results of bioinformatics analysis showed that 417 mRNAs were differentially expressed between control group and test group IV (fold change ≥ 2.0, P < 0.05). Among them, 160 mRNAs presented upregulated and 257 were downregulated. The differentially expressed mRNAs were mainly involved in Melanogenesis, Calcium signaling pathway, Wnt signaling pathway, mTOR signaling pathway, and Vascular smooth muscle contraction.
Project description:Gene expression determination between breast muscle associated with the phenotypic expression of feed efficiency (FE) in a single male broiler line. Goal was to determine the changes of gene expression by feed efficiency (FE). Two-condition experiment, high feed efficiency vs. low feed efficiency. Biological replicates: breast muscles from 4 high feed efficiency male broiler, breast muscles from 4 low feed efficiency male broiler
Project description:Abstract: Ammonia is one of the most prominent air pollutants in poultry houses. High levels of ammonia have adverse effects on respiratory health, growth performance, meat production of broilers, and breast meat growth and yield are critical important in the broiler industry. To date, studies focus on the negative relationship of ammonia exposure and breast muscle tissue are still very limited, and the underlying molecular mechanisms remain poorly understood. In this study, high concentrations of atmospheric ammonia were found to lower slaughter rate and broiler breast meat yield significantly (P < 0.05). To explore the candidate genes that ammonia regulates breast meat yield of broilers, high throughout RNA-Seq was used to compare the transcriptome of breast muscle with different ammonia exposure (50 ppm vs 3 ppm). In total, 129 differentially expressed genes (DEGs) were identified (P-value < 0.05; fold-change ≥ 2), among which 87 genes were significantly down-regulated and 42 were up-regulated. Bioinformatics analysis suggested that DEGs (such as PDK4, ACSL1, GLUL, FBXO32) were involved in fatty acid degradation/metabolism, nitrogen metabolism, PPAR signaling and adipocytokine signaling pathways. Functional annotation showed that DEGs were mainly enriched in reactive oxygen species metabolic process and muscle contraction. It can be concluded that decreased meat yield was due to the DEGs participating in above biological processes and pathways. This study provides novel insights into transcriptional differences in breast meat between high- and low-ammonia exposed broiler chickens.