Project description:Affymetrix GeneChip miRNA Array was used to globally identify different expression miRNAs in hypothalamus, liver, breast muscle and abdominal fat between commercial broilers and indigenous chickens at seven-week old with hypertrophic pectoral muscle or normal pectoral muscle.
Project description:Detection of differentially expressed genes in broiler Pectoralis major muscle affected by White Striping – Wooden Breast myopathies
Project description:Breast muscle myopathies in broilers compromise meat quality and continue to plague the poultry industry. Broiler breast muscle myopathies are characterized by impaired satellite cells (SC)-mediated repair, and localized tissue hypoxia and dysregulation of oxygen homeostasis have been implicated as contributing factors. The present study was designed to test the hypothesis that hypoxia disrupts the behavior of SC essential for multinucleated myotube formation in vitro, and to determine the extent to which effects are reversed by restoration of oxygen tension. Primary SC was isolated from pectoralis major of young (5 d) Cobb 700 chicks and maintained in growth conditions or induced to differentiate under normoxic (20% O2) or hypoxic (1% O2) conditions for up to 48 h. Hypoxia enhanced SC proliferation while inhibiting myogenic potential, with decreased fusion index and suppressed myotube formation. Reoxygenation after hypoxia partially reversed effects on both proliferation and myogenesis. Western blotting showed that hypoxia diminished myogenin expression, activated AMPK, upregulated proliferation markers, and increased molecular signaling of cellular stress. Hypoxia also promoted accumulation of lipid droplets in myotubes. Targeted RNAseq identified numerous differentially expressed genes across differentiation under hypoxia, including several genes that have been associated with myopathies in vivo. Altogether, these data demonstrate localized hypoxia may influence SC behavior in ways that disrupt muscle repair and promote the formation of myopathies in broilers.
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:With the development of the poultry industry, ammonia, as a main contaminant in the air, is causing increasing problems with broiler health. To date, most studies of ammonia toxicity have focused on the nervous system and the gastrointestinal tract in mammals. However, few detailed studies have been conducted on the hepatic response to ammonia toxicity in poultry. The molecular mechanisms that underlie these effects remain unclear. In the present study, our group applied isobaric tags for relative and absolute quantitation (iTRAQ) - based quantitative proteomic analysis to investigate changes in the protein profile change in hepatic tissue of broilers exposed to high concentrations of atmospheric ammonia, with the goal of characterizing the molecular mechanisms of chronic liver injury from exposure to high ambient levels of ammonia. Overall, 30 differentially expressed proteins that are involved in nutrient metabolism (energy, lipid and amino acid), immune response, transcriptional and translational regulation, stress response and detoxification were identified. In particular, two of these proteins, beta-1 galactosidase (GLB1), and a kinase (PRKA) anchor protein 8-like (AKAP8 L), were previously suggested to be potential biomarkers of chronic liver injury. In addition to the changes in the protein profile, serum parameters and histochemical analyses of hepatic tissue also showed extensive hepatic damage in ammonia-exposed broilers. Altogether, these findings suggest that longtime exposure to high concentrations of atmospheric ammonia can trigger chronic hepatic injury in broilers via different mechanisms, providing new information that can be used for intervention using nutritional strategies in the future.
Project description:Multi-tissue transcriptomic analysis to reveal the effect of L-methionine supplementation in broiler chickens under acute heat stress
Project description:In the current study, we expanded our previous work to identify miRNAs implicated in the myogenesis regulation through the comparison of miRNAs transcriptome in skeletal muscle tissues between broilers and layers. To address that, we firstly performed Solexa deep sequencing to profile miRNAs expressed in chicken skeletal muscle tissues. Sequence tags analyses not only enable us to report a group of highly abundant known miRNAs expressed in skeletal muscles but most importantly to identify novel putative chicken miRNAs from skeletal muscle tissue. Further miRNA transcriptome comparison and real-time RT-PCR validation experiments revealed seveal differentially expressed miRNAs between broilers and layers.