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Articles 1 - 10 of 10
Full-Text Articles in Life Sciences
Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian
Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian
Graduate Theses, Dissertations, and Problem Reports
Specialized metabolites produced by fungi impact human health. A large portion of the pharmaceuticals currently on the market are derived from metabolites biosynthesized by microbes. Ergot alkaloids are a class of fungal metabolites that are important in the interactions of environmental fungi with insects and mammals and also are used in the production of pharmaceuticals. In animals, ergot alkaloids can act as partial agonists or antagonists at receptors for 5-hydroxytryptamine (serotonin), dopamine, and noradrenaline as ergot alkaloids have chemical structures similar to those neurotransmitters. Therefore, they affect insects and mammals that consume them and can be used to produce drugs …
Diversification Of Ergot Alkaloid Biosynthesis In Natural And Engineered Fungi, Kyle Austin Davis
Diversification Of Ergot Alkaloid Biosynthesis In Natural And Engineered Fungi, Kyle Austin Davis
Graduate Theses, Dissertations, and Problem Reports
Ergot alkaloids are a complex family of tryptophan-derived mycotoxins produced by a diverse range of fungi that occupy a wide variety of ecological niches including soil saprotrophs, plant endophytes, pathogens of plants or insects, and opportunistic pathogens of humans and other mammals. Ergot alkaloids are a similarly diverse family of chemicals that elicit a variety of pharmacological activities in animals due to their resemblance to neurotransmitters and high binding affinity for neurological receptors, including those that bind adrenaline, dopamine, and 5-hydroxytryptamine receptors. These structural similarities allow us to create medicines aimed at treating a range of neurological diseases and disorders …
Impact Of Ergot Alkaloid And Estradiol 17b On Whole-Body Protein Turnover And Expression Of Mtor Pathway Proteins In Muscle Of Cattle, Taylor Dawn Ferguson
Impact Of Ergot Alkaloid And Estradiol 17b On Whole-Body Protein Turnover And Expression Of Mtor Pathway Proteins In Muscle Of Cattle, Taylor Dawn Ferguson
Theses and Dissertations--Animal and Food Sciences
Beef cattle consuming endophyte infected tall fescue typically exhibit reduced performance in terms of both decreased dry matter intake (DMI) and growth rates. It has been suggested that lower concentrations of circulating IGF-1 (an important stimulator of the mTOR pathway and ultimately protein synthesis), as observed with consumption of ergot alkaloids, contribute to reduced growth rates. The objective of the current study was to determine if fescue-derived alkaloids decrease muscle protein synthesis though inhibitory action on the mTOR pathway via a direct effect on signal proteins, and if these negative effects can be alleviated by implantation with anabolic agents. Thirty-two …
Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust
Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust
Graduate Theses, Dissertations, and Problem Reports
Ergot alkaloids are fungal tryptophan derived toxins which affect mammalian circulation and neurotransmission. These compounds are biosynthesized by a conserved genetic pathway, known as the ergot alkaloid synthesis (EAS) pathway by fungi belonging to the ascomycete families Trichocomaceae and Clavicipitaceae. Several Ipomoea species and related plants in the morning glory family harbor vertically transmitted symbiotic fungi in the genus Periglandula, also members of Clavicipitaceae, that produce ergot alkaloids. Metabolomic analysis of seeds identified a previously uncharacterized glycoside form of the pharmaceutically important ergot alkaloid, ergonovine. Several species belonging to the fungal genus Metarhizium have recently been shown to have the …
Alternative Feeding Strategies For Growing Cattle Grazing Endophyte-Infected Tall Fescue During The Summer, Kerri A. Johnson
Alternative Feeding Strategies For Growing Cattle Grazing Endophyte-Infected Tall Fescue During The Summer, Kerri A. Johnson
MSU Graduate Theses
Two experiments were conducted to determine animal performance of alternative feeding strategies to heifers grazing endophyte-infected tall fescue during summer months. In Experiment 1, 40 Limousin heifers (261± 40kg initial BW) were stratified by weight and assigned to either a spring harvested tall fescue silage diet or grazing endophyte-infected tall fescue pasture with grain supplement having either natural or artificial shade for 80 days. In Experiment 2, 40 Limousin heifers (277 ± 44kg initial BW) were stratified by weight and assigned to either a traditional grain supplement or feather-meal supplement (rumen bypass arginine supplement) with natural or artificial shade while …
Influence Of Ergot Alkaloids On Rumen Motility: Time And Concentration Of Ergovaline + Ergovalinine Required To Impact Reticulorumen Motility, Kara Riccioni
Theses and Dissertations--Animal and Food Sciences
Fescue toxicosis is problematic for ruminant livestock, causing weight loss and low productivity when fed endophyte-infected forages. Complete underlying mechanisms of toxicosis are unknown therefore; the objective of the study was to determine if ruminally dosed ergot alkaloids impact rumen motility. Cannulated steers were pair-fed a forage diet and ruminally dosed with endophyte-free (E-) or endophyte-infected (E+) tall fescue seed. An 8-h period of rumen motility collection began 4-h after feeding by monitoring pressure change via a wireless telemetry and transducer system. In experiment 1, steers were paired by weight and assigned to E- or E+ treatment. Overall, E+ steers …
Association Of Genotype At Drd2 With Growth And Reproductive Performance Traits In Bulls Grazing Toxic Endophyte-Infected Tall Fescue, Kaysie Jennings
Association Of Genotype At Drd2 With Growth And Reproductive Performance Traits In Bulls Grazing Toxic Endophyte-Infected Tall Fescue, Kaysie Jennings
Masters Theses
Fescue toxicosis can negatively impact growth and fertility of beef cattle grazing tall fescue infected with an endophytic fungus. The fungus produces ergot alkaloids that contribute to the hardiness of the plant, but can be detrimental to the animal if consumed. A single nucleotide polymorphism (SNP) in the dopamine receptor D2 gene (DRD2) has been associated with serum prolactin concentrations and hair coat scores in cattle grazing toxic endophyte-infected (TE) tall fescue; cattle with the GG genotype had decreased serum prolactin concentrations and increased hair coat scores. Separately, heifers with the AA genotype calved sooner than AG or GG heifers. …
Interaction Of Isoflavones And Endophyte-Infected Tall Fescue Seed Extract On Vasoactivity Of Bovine Mesenteric Vasculature, Yang Jia
Theses and Dissertations--Animal and Food Sciences
Endophyte-infected tall fescue produces many ergot alkaloids, which have been shown to be vasoconstrictive in various vessel types of bovine. On the other hand, substantial evidence has been reported on the vasodilative effects of formononetin and biochanin A in different vessel types in humans and rats. So, a study was conducted using mesenteric vasculature collected from heifers shortly after slaughter. After 2-h incubation with formononetin (F), biochanin A (B), or an ergovaline-containing tall fescue seed extract (EXT) and their combinations, vessels were mounted in a multi-myograph to determine their ergotamine-induced contractility. Results indicated that F and B at 1 × …
Use Of Mtb-100tm, Provided Through A Mineral Mix, To Reduce Toxicity When Lactating Beef Cows Graze Endophyte-Infected Tall Fescue, Melanie E. Hoar
Use Of Mtb-100tm, Provided Through A Mineral Mix, To Reduce Toxicity When Lactating Beef Cows Graze Endophyte-Infected Tall Fescue, Melanie E. Hoar
Theses and Dissertations--Animal and Food Sciences
Two experiments were conducted at the University of Kentucky, Eden Shale Farm, Owenton, KY to evaluate the use of MTB-100TM (Alltech, Inc., Nicholasville, KY) to alleviate the symptoms of fescue toxicity when lactating Angus x Beefmaster cows and their calves grazed endophyte-infected KY-31 tall fescue. Experiment 1 provided a carbohydrate based toxin adsorbent, MTB-100TM, ad libitum in a commercial mineral supplement to project a daily consumption rate of 0, 20 or 40 g of MTB-100TM per cow. Cows were weighed, assigned a body condition score (BCS) and hair coat score (HC), rectal temperatures were recorded and …
Effects Of Ergot Alkaloids And Antioxidants On Bovine Sperm Motility, Ryan James Page
Effects Of Ergot Alkaloids And Antioxidants On Bovine Sperm Motility, Ryan James Page
Graduate Theses and Dissertations
The studies that comprise this thesis were performed in an attempt to identify and eliminate stressful conditions that may lead to infertility in the male bovine. The first project was performed to determine if ergot alkaloids directly affect bovine sperm motility. Percentage of motile spermatozoa was affected (P = 0.015) by a three-way interactions between time, concentration, and alkaloid. Ergotamine and dihydroergotamine decreased (P = 0.01) sperm motility in a concentration and time dependant manner and ergonovine had a minimal effect on overall sperm motility. The number of static spermatozoa also was affected (P < 0.01) by a three way interaction and increased as ET and DHET concentrations increased. Percentages of progressively motile and rapidly motile spermatozoa decreased (P < 0.01) in a two way interaction between alkaloid and concentration. Overall, sperm motility was decreased by ET and DHET. Furthermore, the qualities of motility as represented by progressive, rapid, path velocity (VAP), progressive velocity (VSL), track speed (VCL), beat frequency (BCF), lateral amplitude (ALH), straightness (STR), elongated, and area were decreased by those alkaloids. These data verify that ergot alkaloids commonly found in toxic tall fescue are detrimental to bovine spermatozoa. In the second study two antioxidants (alpha-tocopherol and ascorbic acid) were added to bovine sperm culture media and cryopreservation extender. The antioxidant capabilities of these two vitamins could help reduce free radical production and help preserve sperm viability. There was an interactive effect between ascorbic acid concentration and storage method on the bovine sperm motility characteristics: motile, progressive, rapid, track speed (VCL), and straightness (P < 0.05). A bull by ascorbic acid interaction (P < 0.05) was observed for motile, progressive, rapid, path velocity (VAP), progressive velocity (VSL), and VCL characteristics. Alpha tocopherol had no affects on sperm motility characteristics. Lipid peroxidation was affected (P < 0.01) by bull and ascorbic acid. Malondialdehyde concentrations for ascorbic acid treatments (0, 5, 10, 20 mM) were 3.25, 4.2, 2.96, and 2.15 ìM respectively. Results from the second study indicate that the addition of ascorbic acid may reduce sperm motility, but help prevent lipid peroxidation.