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: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: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:Within the human gut reside diverse microbes coexisting with the host in a mutually advantageous relationship. We comprehensively identified the modulatory effects of phylogenetically diverse human gut microbes on the murine intestinal transcriptome. Gene-expression profiles were generated from the whole-tissue intestinal RNA of mice colonized with various single microbial strains. The selection of microbe-specific effects, from the transcriptional response, yielded only a small number of transcripts, indicating that symbiotic microbes have only limited effects on the gut transcriptome overall. Moreover, none of these microbe-specific transcripts was uniformly induced by all microbes. Interestingly, these responsive transcripts were induced by some microbes but repressed by others, suggesting different microbes can have diametrically opposed consequences.
Project description:A minor population of M cells within the follicle-associated epithelium (FAE) of intestinal Peyer’s patches (PP) serves as a major portal for entry of exogenous antigens. Characterization of the mammalian M cells, including identification of M-cell surface molecules used for bacterial uptake, has been hampered by their relative rarity. In contrast, M cells constitute virtually all of the FAE cells in the avian bursa of Fabricius. We therefore performed comparative gene expression profiling of chicken and murine FAE to identify commonly expressed genes by M cells in both species. The comprehensive transcriptome analysis revealed that 28 genes were commonly up-regulated in FAE from both species. In situ hybridization (ISH) revealed that annexin A10 (Anxa10) mRNA was scattered in FAE, and co-localized with Ulex europaeus agglutinin-1(UEA-1) that binds to M cells. Whole-mount immunostaining also revealed that cellular prion protein (PrPC) was expressed on the luminal side of the apical plasma membrane of M cells, and co-localized with grycoprotein2 (GP2) that recognizes only M cells in murine PP. Taken together, we found new M-cell-specific molecules by using comprehensive transcriptome analysis. These molecules conserved in M cells from both species might play critical roles in M-cell function and/or differentiation.