title: Toxicological and gene expression analysis of the impact of aflatoxin B1 on hepatic function of male broiler chicks.
abstract: The objective of this study was to determine the effects of dietary aflatoxin B1 (AFB1) on hepatic gene expression in male broiler chicks. Seventy-five 1-d-old male broiler chicks were assigned to 3 dietary treatments (5 replicates of 5 chicks each) from hatch to d 21. The diets contained 0, 1 and 2 mg of AFB1/kg of feed. Aflatoxin B1 reduced (P<0.05) feed intake, BW gain, serum total proteins, and serum Ca and P, but increased (P<0.01) liver weights in a dose-dependent manner. Microarray analysis was used to identify shifts in genetic expression associated with the affected physiological processes in chicks fed 0 and 2 mg of AFB1/kg of feed to identify potential targets for pharmacological/toxicological intervention. A loop design was used for microarray experiments with 3 technical and 4 biological replicates per treatment group. Ribonucleic acid was extracted from liver tissue, and its quality was determined using gel electrophoresis and spectrophotometry. High-quality RNA was purified from DNA contamination, reverse transcribed, and hybridized to an oligonucleotide microarray chip. Microarray data were analyzed using a 2-step ANOVA model and validated by quantitative real-time PCR of selected genes. Genes with false discovery rates less than 13% and fold change greater than 1.4 were considered differentially expressed. Compared with controls (0 mg of AFB1/kg), various genes associated with energy production and fatty acid metabolism (carnitine palmitoyl transferase), growth and development (insulin-like growth factor 1), antioxidant protection (glutathione S transferase), detoxification (epoxide hydrolase), coagulation (coagulation factors IX and X), and immune protection (interleukins) were downregulated, whereas genes associated with cell proliferation (ornithine decarboxylase) were upregulated in birds fed 2 mg of AFB1/kg. This study demonstrates that AFB1 exposure at a concentration of 2 mg/kg results in physiological responses associated with altered gene expression in chick livers.
authors.affiliation: Department of Animal Sciences, and Veterinary Medical Diagnostic Laboratory, University of Missouri, Columbia 65211, USA.
authors.forename: L P
authors.initials: LP
authors.lastname: Yarru
authors.forename: R S
authors.initials: RS
authors.lastname: Settivari
authors.forename: E
authors.initials: E
authors.lastname: Antoniou
authors.forename: D R
authors.initials: DR
authors.lastname: Ledoux
authors.forename: G E
authors.initials: GE
authors.lastname: Rottinghaus
mesh_terms: D016604:Aflatoxin B1 / Q000633:toxicity*; D000818:Animals; D030161:Avian Proteins / Q000235:genetics; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D016678:Genome; D008099:Liver / Q000187:drug effects*; D008297:Male; D011042:Poisons / Q000633:toxicity*; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D030161:Avian Proteins; D011042:Poisons; D016604:Aflatoxin B1