Project description:We report the hepatic response of broiler chickens to an increase in stocking density. Here we compare gene expression profiles of liver cells via RNA-seq of broiler chicken raised under a high stocking density to broiler chickens raised under a lower stocking density with the objective of this study being to identify biomarkers of stress before the clinical and economic impacts are observed. We found that increasing stocking density seems to have a unique impact on hepatic gene expression prior to eliciting common clinical signs associated with stress. The cellular functions that are most affected appear to be those involved in steroidogenesis and cell movement/migration as identified by RNA-seq analysis of the liver transcriptome. These results could provide a baseline of information that future research to identify genes or molecules that could aid in the detection of negative effects of stressors such as stocking density prior to negative clinical and economic signs presenting themselves.
Project description:An experiment was conducted to investigate the effects of dietary inclusion of rye, a model ingredient to increase gut viscosity, between 14 and 28 days of age on immune competence related parameters and performance of broiler. A total number of 960 one-day-old male Ross 308 chicks were weighed and randomly allocated to 24 pens (40 birds per pen), and the birds in every 8 replicate pens were assigned to one of three experimental diets including graded levels, 0%, 5%, and 10% of rye. Tested immune competence related parameters were composition of the intestinal microbiota, genes expression in gut tissue, and gut morphology. The inclusion of 5% or 10% rye in the diet (d14-28) resulted in decreased performance and litter quality, but in increased villus height and crypt depth in the small intestine (jejunum) of the broilers. Relative bursa and spleen weights were not affected by dietary inclusion of rye. In the jejunum, no effects on number and size of goblet cells, and only trends on microbiota composition in the digesta were observed. Dietary inclusion of rye affected expression of genes involved in cell cycle processes of the jejunal enterocyte cells, thereby influencing cell growth, cell differentiation and cell survival, which in turn were consistent with the observed differences in the morphology of the gut wall. In addition, providing rye-rich diets to broilers affected the complement and coagulation pathways, which are parts of the innate immune system. These pathways are involved in eradicating invasive pathogens. Overall, it can be concluded that inclusion of 5% or 10% rye to the grower diet of broilers had limited effects on performance. Ileal gut morphology, microbiota composition of jejunal digesta, and gene expression profiles of jejunal tissue, however, were affected by dietary rye inclusion level, indicating that rye supplementation to broiler diets might affect immune competence of the birds.
Project description:Submerged cultivation using low-value agro-industrial side streams allows large-scale and efficient production of fungal mycelia, which has a high nutritional value. As the dietary properties of fungal mycelia in poultry are largely unknown, the present study aimed to investigate the effect of feeding a Pleurotus sapidus (PSA) mycelium as a feed supplement on growth performance, composition of the cecal microbiota and several physiological traits including gut integrity, nutrient digestibility, liver lipids, liver transcriptome and plasma metabolome in broilers. 72 male, 1-day-old Cobb 500 broilers were randomly assigned to three different groups and fed three different adequate diets containing either 0% (PSA-0), 2.5% (PSA-2.5) and 5% (PSA-5.0) P. sapidus mycelium in a three-phase feeding system for 35 days. Each group consisted of 6 cages (replicates) with 4 broilers/cage. Body weight gain, feed intake and feed:gain ratio and apparent ileal digestibility of crude protein, ether extract and amino acids were not different between groups. Metagenomic analysis of the cecal microbiota revealed no differences between groups, except that one α-diversity metric (Shannon index) and the abundance of two low-abundance bacterial taxa (Clostridia UCG 014, Eubacteriales) differed between groups (P < 0.05). Concentrations of total and individual short-chain fatty acids in the cecal digesta and concentrations of plasma lipopolysaccharide and mRNA levels of proinflammatory genes, tight-junction proteins, and mucins in the cecum mucosa did not differ between groups. None of the plasma metabolites analyzed using targeted-metabolomics differed across the groups. Hepatic transcript profiling revealed a total of 144 transcripts to be differentially expressed between group PSA-5.0 and group PSA-0 but none of these genes was regulated greater 2-fold. Considering either the lack of effects or the very weak effects of feeding the P. sapidus mycelium in the broilers it can be concluded that inclusion of a sustainably produced fungal mycelium in broiler diets at the expense of other feed components has no negative consequences on broilers´ performance and metabolism.
Project description:Stocking density is considered as a key factor determining the productivity of fish aquaculture systems. The transcriptomic response to crowding stress is, however, still poorly investigated. We aimed at the identification of potential biomarker genes via microarray analyses to get insight into molecular pathways modulated through density-induced stress in farmed rainbow trout Oncorhynchus mykiss. Transcriptome profiling in liver, kidney, and gills was complemented with behaviarol observation and analysis of classical plasma parameters. Individuals of two trout strains were exposed for eight days to definite stocking densities, 1 kg/m³ (low density); 10 kg/m³ (moderate); 18 kg/m³ (elevated); and 35 kg/m³ (high). Whereas stocking density had no significant effect on cortisol levels, plasma glucose levels were elevated in trout kept at high density. Pathway enrichment analyses confirmed the upregulation of HIF1a signaling in liver contributing to glucose homeostasis during stress conditions, while mTOR and PI3K/AKT signaling pathways were downregulated. Further perturbed hepatic pathways were involved in protein ubiquitination and the biosynthesis of cholesterol, retinol and glutathione. Three stocking density conditions were investigated: an uncrowded âmoderateâ density (MD: 10 kg trout/m³) , an elevated density (ED: 18 kg/m³ ), and high density (HD: 35 kg/m³). The experiment was performed twice with two strains of Steelhead rainbow trout (Troutlodge and Born trout), randomly assigned to identical glass tanks with MD (30 and 34 individuals), ED (60 and 64 individuals), and HD (120 and 140 individuals). Trout were sampled 8 d after experimental onset.
Project description:The spatial organization of gut microbiome is essential for their interactions with the host. Recently, microbiota alteration in ileum is getting the increasing recognition due to the close interplay with inflammatory diseases and the tumor immunosurveillance. However, how ileal microbiome is spatially regulated remains unclear. Here, we show that DNA-damaging chemotherapy specifically remodels microbiota in ileal mucosa, resulting in the overgrowth of local family Lachnospiraceae that promotes antitumor immunity and synergizes with immune checkpoint blockage. Mechanistically, the prominent proliferative state of transit amplifying cells (TACs) in the ileal crypt presents a vulnerability to chemotherapy-caused genomic stress, resulting in the accumulation of cytosolic dsDNA that subsequently activates AIM2 inflammasome. AIM2-dependent production of IL18 boosts Th1 immunity in ileal lamina propria, which further impairs the antimicrobial host defense of proximal Paneth cells via activating IFN-γ-JAK-STAT signaling. Our findings demonstrate that AIM2 inflammasome shapes ileal microbiome via governing the compartmentalized cellular interplay in ileal crypt, providing mechanistic insights into the regulation of gut biogeography and implicating therapeutic strategies of spatial microbiome intervention using chemotherapy.