Effects of Fescue Toxins On Hepatic Gene Expression in Mice.
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ABSTRACT: Fescue toxicosis is a disease of wild and domestic animals grazing on fescue pasture infected with the endophytic fungus, Neotyphodium Coenophialum. Mice, previously selected for increased sensitivity to endophyte-infected fescue seed diets indicated by slow weight gain, were used to study the effects of fescue toxicosis on hepatic gene expression. Liver genes differentially expressed due to fescue toxins were studied using DNA microarray. A two-stage ANOVA of microarray data identified forty differentially expressed genes between mice fed endophyte-infected (E+) and endophyte-free (E-) fescue seeds. Significant Analysis of Microarray (SAM) analysis identified 9 genes as differentially expressed between treatment groups. Hierarchical clustering with the 40 genes identified by ANOVA clearly separate the mice according to their diets, with 100% confidence as computed by bootstrap analysis. Expressions of eleven genes were verified using quantitative real-time PCR (qPCR). The E+ diet resulted in downregulation of genes involved in sex-steroid metabolism pathway, genes involved in cholesterol and lipid metabolism. Keywords = Endophyte Keywords = Fescue Toxicosis Keywords = microarray Keywords: repeat sample
Project description:Rats (n=24) were fed ad libitum diets containing either ground endophyte-free (E-) seed or endophyte–infected (E+) seed for five days at thermoneutrality (21°C). Rats (n=24) with intraperitonial transmitters were used with core temperature (Tc) and general activity measured every 5 minutes during the study. At treatment end, the liver was removed, weighed and frozen in liquid nitrogen. Twelve rats were selected for microarray experiments, based on degree of sensitivity to fescue toxicosis. Degree of sensitivity was based on changes in relative liver weights, feed intake, average daily gain, and Tc from pretreatment levels. RNA was extracted from liver samples, converted to cDNA, and hybridized with the printed oligonucleotide slides. The microarray data was analyzed using Wolfinger's two step ANOVA model. Keywords: repeat sample
Project description:Rats (n=24) were fed ad libitum diets containing either ground endophyte-free (E-) seed or endophyteâ??infected (E+) seed for five days at thermoneutrality (21°C). Rats (n=24) with intraperitonial transmitters were used with core temperature (Tc) and general activity measured every 5 minutes during the study. At treatment end, the liver was removed, weighed and frozen in liquid nitrogen. Twelve rats were selected for microarray experiments, based on degree of sensitivity to fescue toxicosis. Degree of sensitivity was based on changes in relative liver weights, feed intake, average daily gain, and Tc from pretreatment levels. RNA was extracted from liver samples, converted to cDNA, and hybridized with the printed oligonucleotide slides. The microarray data was analyzed using Wolfinger's two step ANOVA model.
Project description:The objective of our study was to assess the effect of fescue toxicosis on the overall transcriptomics profile of liver tissue on growing Angus × Simmental steers and heifers. The susceptibility was determined by the T-snip genetic tests for a total of 42 pregnant cows. At mid-gestation, these animals were randomly assigned to control group which received a based diet and fed endophyte free fescue seeds; a treatment group was fed endophyte-infected tall fescue seeds for 30 days. RNA-seq experiments were performed in liver biopsy samples, and a total of 828 differentially expressed genes were detected.
Project description:Fescue toxicosis affects wild and domestic animals consuming ergot alkaloids contained in tall fescue forage infected with the endophytic fungus, Neotyphodium coenophialum. , When animals are consuming infected fescue forage during periods of elevated ambient temperatures (summer), a range of phenotypic disorders collectively called summer slump is observed. It is characterized by hyperthermia, with an accompanying decrease in feed intake, growth, milk yield and reproductive fitness. Laboratory mice also exhibit symptoms of fescue toxicosis a thermoneutral temperature, as indicated by reduced growth rate and reproductive fitness. Our goal was to characterize the differences in gene expression in liver of mice exposed to summer-type heat stress (HS) and infected fescue (E+) when compared to mice fed infected fescue at thermoneutral temperature (TN). Mice were fed E+ diet under HS (34 ± 1°C; n = 13; E+HS) or thermoneutral (TN) conditions (24 ± 1°C; n = 14; E+TN) for a period of two weeks between 47 to 60 d of age. Genes differentially expressed between E+HS versus E+TN were identified using DNA microarrays. Forty-one genes were differentially expressed between treatment groups. Expressions of eight genes were measured using quantitative real-time PCR. Genes coding for phase I detoxification enzymes were up-regulated in E+HS mouse liver. This detoxification pathway is known to produce reactive oxidative species. We observed an up-regulation of genes involved in the protection against reactive oxidative species. Key genes involved in de novo lipogenesis and lipid transport were also up-regulated. Finally, genes involved in DNA damage control and unfolded protein responses were down-regulated. Keywords: Stress response
Project description:Neotyphodium coenophialum is an endophytic fungus that infects most tall fescue (Festuca arundinacea) pastures that are commonly used in animal grazing systems in the United States. Beef cattle grazing such pastures are impaired in health and production performance, resulting in a large economic loss in US food-animal production systems. Based on clinical and biochemical blood analyte profiles, hepatic targeted gene and protein analyses, and hepatic transcriptomic profiling, microarray analysis using the WT Btau 4.0 Array (version 1.0, Affymetrix, Inc., Santa Clara, CA) was conducted to determine if grazing endophyte-infected tall fescue pastures affects pituitary gene expression profiles of growing beef steers. The specific overall hypothesis tested was that grazing high endophyte-infected pasture would alter the pituitary genomic expression profiles of the same growing steers, especially genes involved in production and secretion of prolactin, growth hormone, thyroid stimulating hormone, and adrenocorticotropic hormone. Sixteen steers were assigned to graze either a low toxic endophyte tall fescue-mixed grass (LE treatment, 5.7 ha, n = 8) or a high toxic endophyte infected tall fescue (HE treatment, 5.7 ha, n = 8) pasture located in the University of Kentucky Agricultural Research Center. All steers had ad libitum access to fresh water, an industry standard mineral-vitamin supplement, and grazed respective pastures for 89 to 105 days. Whole pituitaries were collected for RNA extraction and microarray analysis.
Project description:The objectives of our study were to identify microRNA (miRNA) present in bovine sperm and to evaluate the effects of fescue toxicosis on sperm miRNA expression. Angus bulls were assigned to treatments of either toxic or non-toxic fescue seed diets. Semen was collected and subjected to microRNA (miRNA) isolation after 126 days. Three bull's sperm miRNA samples from each treatment group were chosen and pooled for deep sequencing. Sequencing results were used to create a custom microarray for miRNA comparison between groups. LC Sciences was used as a service provider for the sequencing and custom microarray.
Project description:Neotyphodium coenophialum is an endophytic fungus that infects most tall fescue (Festuca arundinacea) pastures that are commonly used in animal grazing systems in the United States. Beef cattle grazing such pastures are impaired in health and production performance, resulting in a large economic loss in US food-animal production systems. Based on the clinical symptoms and laboratory analyses of blood, it was hypothesized that such affected cattle display liver-specific changes in the expression of gene transcripts that are associated with the metabolic enzymes and transporters critical for beef health and performance. Microarray analysis using the GeneChip Bovine Genome Array (Affymetrix, Inc., Santa Clara, CA) was conducted to determine if grazing endophyte-infected tall fescue pastures affects the liver gene expression profiles of growing beef steers. Nineteen steers were assigned to graze either a low toxic endophyte tall fescue-mixed grass (LE treatment, 5.7 ha, n = 9) or a high toxic endophyte infected tall fescue (HE treatment, 5.7 ha, n = 10) pasture located in the University of Kentucky Agricultural Research Center. All steers had ad libitum access to fresh water and an industry standard mineral-vitamin supplement. 88 days grazing on pasture. Approximately 2 g of tissue from the right lobe of the liver of each steer were collected for RNA extraction and microarray analysis.
Project description:Gene expression analysis in heifer luteal tissue by interspecies microarray analysis. Post-pubertal heifers were fed diets containing endophyte free fescue seed (EF), endophyte infected fescue seed (EI) or EI seed supplemented with 1.44 mg domperidone/kg body weight (EID). One heifer from each treatment group was slaughtered at a local abattoir 11-14 days after ovulation (EF = 11d, EI = 14d and EID = 14d ) and used for this study. Ovaries were collected and shipped at room temperature to the laboratory. Approximately 3 mm3 samples of luteal tissue were placed in cryovials and frozen at -80°C until processed. One 3 mm3 sample each for the EI and EID treatments and two samples for the EF treatment were ground to a fine powder in liquid N and total RNA was extracted using the RNeasy® Mini Kit (Qiagen, Valencia, CA). Quality and quantity of RNA was determined by gel electrophoresis and spectrophotometry. Five µg of total RNA was converted to cDNA and then biotin-labeled cRNA by linear amplification (CodeLink® Expression Bioarrays, Amersham Biosciences Corp, Piscataway, NJ, USA). Ten micrograms of labeled cRNA were hybridized to CodeLink UniSet Rat I Bioarray (Amersham Biosciences Corp, Piscataway, NJ, USA) by the Amersham Biosciences Facility. Keywords: other
Project description:Neotyphodium coenophialum is an endophytic fungus that infects most tall fescue (Festuca arundinacea) pastures that are commonly used in animal grazing systems in the United States. Beef cattle grazing such pastures are impaired in health and production performance, resulting in a large economic loss in US food-animal production systems. Based on clinical and biochemical blood analyte profiles, hepatic targeted gene and protein analyses, and hepatic transcriptomic profiling, microarray analysis using the BovGene-1_0-v1 array (Affymetrix) was conducted to determine if grazing endophyte-infected tall fescue pastures affects pituitary gene expression profiles of growing beef steers. The specific overall hypothesis tested was that grazing high endophyte-infected pasture would alter the pituitary genomic expression profiles of the same growing steers, especially genes involved in production and secretion of prolactin, growth hormone, thyroid stimulating hormone, and adrenocorticotropic hormone.
Project description:Pregnant Suffolk ewes (n = 19; 81.2kg ± 7.7) estimated to be carrying twins were assigned to endophyte-infected tall fescue seed (E+; 4.14 µg ergovaline + ergovalinine/g seed) or a control diet (CON; 0 µg ergovaline + ergovalinine) and evaluated at different stages of gestation (gd85 [pre-treatment, n = 3], gd110 [n = 4/treatment] or gd133 [n = 4/treatment). Ewes were individually fed a basal diet with (E+) or without (CON) endophyte-infected tall fescue seed from gd86 to gd110 or gd133. A terminal necropsy was performed, and uterine components were evaluated for size, weight, and type. Data were analyzed using a priori contrasts to test effects of stage of gestation (gd85 vs. gd110 or gd110 vs. gd133) and adaptive responses to feeding E+ fescue seed versus CON at gd110 and gd133. Serum prolactin concentrations were greater (P < 0.05) at gd110 than gd85, and then remained constant to gd133. Feeding E+ tall fescue seed reduced (P < 0.05) serum prolactin concentrations compared to CON at both gd110 and gd133. From gd85 to gd110, placentome type and number changed from type A to type B (P < 0.05) but did not change (P > 0.05) after gd110. Total fetal weight per ewe increased 2977 g from gd85 to gd110 (P = 0.011) and then 3151 g from gd110 to 133 (P = 0.012). Brain weight as a percentage of fetal body weight was higher (P = 0.029) for E+ fetuses on gd110 compared to CON, which demonstrates asymmetrical growth and intrauterine growth restriction (IUGR). In total, 15,961 genes were identified in the cotyledon through mapping to the ovine genome across all samples. There were 136 genes differentially expressed (FDR < 0.05; log2foldchange < -1 and > 1) from gd85 to gd110 with ovarian steroidogenesis and steroid biosynthesis pathways enriched and 469 genes differentially expressed from gd110 to gd133 with ribosome and oxidative phosphorylation pathways enriched. Exposure to E+ fescue resulted in differential expression of 22 genes at gd110 but only one gene at gd133 compared to CON. These results show that there are major changes in fetal growth and placental remodeling during the late gestation period that are influenced by exposure to ergot alkaloids from endophyte-infected tall fescue seed; however, major changes in the transcriptome of the cotyledon tissue in response to E+ fescue were not observed and other factors must be involved in the reduction of placental efficiency and fetal growth observed with E+ fescue exposure.