Project description: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: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:Intake of ergot alkaloids associated with endophyte-infected fescue (E+) has adverse effects on animal health and productivity, which is collectively, termed fescue toxicosis. These effects are exacerbated under hot and humid (summer) conditions. A rat model for this condition was used to evaluate the effect of endophytic toxins on hepatic gene expression under acute (three days) heat stress (HS). Core temperature (Tc) was monitored continuously in rats (n=12) implanted with telemetric transmitters. Rats were fed ad libitum an E+ diet and maintained under thermoneutral (TN) conditions (21 ˚C) for five days, followed by TN or HS conditions (31 ˚C) for three days. Feed intake (FI) and body weight (BW) were measured daily. Both E+ and HS induced alterations in hepatic genes were evaluated using DNA microarrays. Intake of E+ reduced FI and BW under TN and HS conditions from pretreatment level, with greater reduction occurring during HS period. Core temperature at TN did not change from pretreatment level, but increased during HS. Genes associated with ATP synthesis, immune function, chaperone activity, and antioxidant function were reduced in E+HS vs E+TN. Present findings suggest that rats respond to E+ during heat stress by inducing hepatic CYP3A4 expression and suppressing chaperone, antioxidant and immune systems, which could ultimately increase the stress resulting in various pathological abnormalities. Keywords: Stress response
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.
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:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.
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:The Norway rat has important impacts on our life. They are amongst the most used research subjects, resulting in ground-breaking advances. At the same time, wild rats live in close association with us, leading to various adverse interactions. In face of this relevance, it is surprising how little is known about their natural behaviour. While recent laboratory studies revealed their complex social skills, little is known about their social behaviour in the wild. An integration of these different scientific approaches is crucial to understand their social life, which will enable us to design more valid research paradigms, develop more effective management strategies, and to provide better welfare standards. Hence, I first summarise the literature on their natural social behaviour. Second, I provide an overview of recent developments concerning their social cognition. Third, I illustrate why an integration of these areas would be beneficial to optimise our interactions with them.