Life Sciences Commons^™

Rnai-Mediated Control Of Aflatoxins In Peanut: Method To Analyze Mycotoxin Production And Transgene Expression In The Peanut/Aspergillus Pathosystem, Renee S. Arias, Phat M. Dang, Victor S. Sobolev

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, …

Ecology, Behavior And Bionomics First Genotyping Of Spodoptera Frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) Progeny From Crosses Between Bt-Resistant And Bt-Susceptible Populations, And 65-Locus Discrimination Of Isofamilies, Renee S. Arias, Maribel Portilla, J. D. Ray, Carlos A. Blanco, S. A. Simpson, Brian E. Scheffler

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Concerns exist that Bt-resistant populations of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) found in Puerto Rico, could spread to continental United States, and about the lack of molecular tools to monitor potential crosses or distinguish populations. In this work, the feasibility of genotyping S. frugiperda crosses between Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) (Bt) resistant and susceptible populations using simple sequence repeats (SSRs, or microsatellites) was assessed. Parents and their corresponding progeny (five resistant, five susceptible phenotype) were genotyped using 192 SSRs on three reciprocate crosses alternating male and female from Bt-susceptible and Bt-resistant populations. Oviposition, mortality and fecundity were …

Effects Of Refuges On The Evolution Of Resistance To Transgenic Corn By The Western Corn Rootworm, Diabrotica Virgifera Virgifera Leconte, Jennifer Deitloff, Mike W. Dunbar, David A. Ingber, Bruce E. Hibbard, Aaron J. Gassmann

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

BACKGROUND: Diabrotica virgifera virgifera LeConte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. Corn producing toxins derived from Bacillus thuringiensis (Bt) has been developed to help manageD. v. virgifera.However, previous studies have demonstrated the ability of this species to evolve resistance to Bt toxins in both laboratory and field settings.

RESULTS: We used an experimental evolution approach to test the refuge strategies for delaying resistance of D. v. virgifera to corn producing Bt toxin Cry34/35Ab1. In the absence of refuges, D. v. virgifera developed resistance to …

Controlling Johne’S Disease: Vaccination Is The Way Forward, John Bannantine, Adel M. Talaat

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

M. avium subspecies paratuberculosis, hereafter referred to as MAP, is a significant veterinary pathogen that causes Johne’s disease in ruminants, including cattle, sheep, and goats. This chronic intestinal disease is distributed worldwide and exacts a heavy eco- nomic toll on animal producers. For example, the dairy industry incurs substantial economic losses due to reduced milk production, premature culling, and reduced slaughter value (Raizman et al., 2009). It takes years for clinical signs to appear in animals after initial infection. The bacterium is shed in high numbers in the feces during this clinical phase of disease. Transmission is by ingestion of …

Characterization Of The Inflammatory Phenotype Of Mycobacterium Avium Subspecies Paratuberculosis Using A Novel Cell Culture Passage Model, Jamie L. Everman, Torsten M. Eckstein, Jonathan Roussey, Paul M. Coussens, John Bannantine, Luiz E. Bermudez

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Understanding the pathogenic mechanisms of Mycobacterium avium subspecies paratuberculosis (MAP) and the host responses to Johne’s disease is complicated by the multi-faceted disease progression, late-onset host reaction and the lack of available ex vivo infection models. We describe a novel cell culture passage model that mimics the course of infection in vivo. The developed model simulates the interaction of MAP with the intestinal epithelial cells, followed by infection of macrophages and return to the intestinal epithelium. MAP internalization triggers a minimal inflammatory response. After passage through a macrophage phase, bacterial reinfection of MDBK epithelial cells, representing the late phase of …

Zap-70, Ctla-4 And Proximal T Cell Receptor Signaling In Cows Infected With Mycobacterium Avium Subsp. Paratuberculosis, Fernando L. Leite, Livia B. Eslabão, Bruce Pesch, J. P. Bannantine, Timothy A. Rienhardt, Judith R. Stabel

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Paratuberculosis is a chronic intestinal disease of ruminant animals caused by Mycobacterium avium subsp. paratuberculosis (MAP). A hallmark of paratuberculosis is a transition from a cell-mediated Th1 type response to a humoral Th2 response with the progression of disease from a subclinical to clinical state. The objective of this study was to investigate the expression of two crucial molecules in T cell function, ZAP-70 (zeta-chain-associated protein of 70kDa) and CTLA-4 (cytotoxic T-lymphocyte antigen-4), in cows naturally infected with MAP. Peripheral blood mononuclear cells (PBMCs) isolated from control non-infected cows (n = 5), and cows in subclinical (n = 6) and …

Mycobacterium Avium Subspecies Paratuberculosis Recombinant Proteins Modulate Antimycobacterial Functions Of Bovine Macrophages, J. P. Bannantine, Judith R. Stabel, Elizabeth Laws, M.C.D. Cardieri, C.D. Souza

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

It has been shown that Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) activates the Mitogen Activated Protein Kinase (MAPK) p38 pathway, yet it is unclear which components of M. paratuberculosis are involved in the process. Therefore, a set of 42 M. paratuberculosis recombinant proteins expressed from coding sequences annotated as lipoproteins were screened for their ability to induce IL-10 expression, an indicator of MAPKp38 activation, in bovine monocyte-derived macrophages. A recombinant lipoprotein, designated as MAP3837c, was among a group of 6 proteins that strongly induced IL-10 gene transcription in bovine macrophages, averaging a 3.1-fold increase compared to non-stimulated macro- phages. However, …

Envelope Protein Complexes Of Mycobacterium Avium Subsp. Paratuberculosis And Their Antigenicity, Fernando L. Leite, Timothy A. Reinhardt, J. P. Bannantine, Judith R. Stabel

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s disease, a chronic enteric disease of ruminant animals. In the present study, blue native PAGE electrophoresis and 2D SDS-PAGE were used to separate MAP envelope protein complexes, followed by mass spectrometry (MS) to identify individual proteins within the complexes. Identity of individual proteins within complexes was further confirmed by MS upon excision of spots from 2D SDS-PAGE gels. Among the seven putative membrane complexes observed, major membrane protein (MAP2121c), a key MAP antigen involved in invasion of epithelial cells, was found to form a complex with cysteine desulfurase (MAP2120c). …

Twelve Years Of Stover Removal Increases Soil Erosion Potential Without Impacting Yield, Virginia L. Jin, Marty R. Schmer, Brian J. Wienhold, Catherine E. Stewart, Gary E. Varvel, Aaron J. Sindelar, Ronald F. Follett, Robert B. Mitchell, Kenneth P. Vogel

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Corn (Zea mays L.) stover (non-grain aboveground biomass) in the US Corn Belt is used increasingly for livestock grazing and co-feed and for cellulosic bioenergy production. Continuous stover removal, however, could alter long-term agricultural productivity by affecting soil organic C (SOC) and soil physical properties, indicators of soil fertility and erosion potential. In this study, we showed that 12 consecutive yr of 55% stover removal did not affect mean grain yields at any N fertilizer rate (4.5, 6.3, and 6.0 Mg ha⁻¹ for 60, 120, and 180 kg N ha⁻¹ yr⁻¹, respectively) in a marginally …

Fertilizers In Aquaculture, Bartholomew Green

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Pond fertilization is an important component of semi-intensive to intensive aquaculture pond management that supports successful production of the culture organism. Semi-intensive and intensive aquaculture pond management fall along the extensive to hyper-intensive management continuum and are characterized by high stocking rate of the culture animal, limited use of fertilizers, use of compound or complete feeds, and water quality monitoring and management, including use of mechanical aeration. Fertilization contributes to establishing and maintaining a pond environment that allows the culture organism to utilize efficiently the compound or complete feeds offered. This chapter presents information on pond food webs, sources and …

Food Reinforcement And Delay Discounting In Zbmi-Discordant Siblings, Denise M. Feda, James N. Roemmich, April Roberts, Leonard H. Epstein

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Objective: The interaction of food reinforcement and the inability to delay gratification are related to adult energy intake and obesity. This study was designed to test the association of sibling pair differences in relative reinforcing efficacy of food and delay discounting on sibling pair differences in zBMI scores of same-gender zBMI-discordant siblings. Design and methods: We tested main and interactive relationships between delay discounting and relative reinforcing efficacy of food on zBMI discordance in 14 zBMI- discordant biological sibling pairs (6 female pairs) using a discordant sibling study design. Results: Sibling pair differences in relative reinforcing efficacy of food were …

Hypoxia Affects Performance Traits And Body Composition Of Juvenile Hybrid Striped Bass (Morone Chrysops X M. Saxatilis), Bartholomew W. Green, Steven D. Rawles, Sidney A. Fuller, Benjamin H. Beck, Matthew E. Mcentire

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0%, and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole-body protein content, whole body compositional indices and nutrient …

Seasonal Variation In Vitamin D Status Of Beef Cattle Reared In The Central United States, E Casas, J D. Lippolis, L A. Kuehn, T A. Reinhardt

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The objective was to retrospectively measure seasonal sunlight-associated variation in serum concentrations of 25-hydroxyvitamin D (25OHD) in beef cattle. The concentration of 25OHD was measured in crossbred animals born from March to May in 2011 and 2012. Vitamin D status 2 to 3 mo after birth (period 1) was only available for 2012 calves and was measured in June 2012. Period 1 animals had serum 25OHD concentrations of 26.3 +- 1.5 ng/mL. The 25OHD concentrations for late summer (period 2) were 46.6 +- 1.4 and 51.0 +- 1.5 ng/mL for 2011 and 2012, respectively. Serum concentration of 25OHD in early …

Nile Tilapia And Blue Tilapia Fry Production In A Subtropical Climate Based On Degree Days, Bartholomew W. Green, Esam H. Rizkalla

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The relationship between production in subtropical earthen ponds of fry suitable for hormonal sex inversion and degree days was quantified for Nile tilapia (Oreochromis niloticus; Egypt strain) and blue tilapia (O. aureus). Degree days were calculated for each trial as the sum of mean daily water column temperature minus the reference temperature, 15◦C. No fry from either species were harvested at fewer than 124–126 degree days. Total fry production for each increased linearly as cumulative degree days increased from 129 to 281 degree days. Production of fry suitable for hormonal sex inversion was positively related to …

Female Breakfast Skippers Display A Disrupted Cortisol Rhythm And Elevated Blood Pressure, Megan Witbracht, Nancy L. Keim, Shavawn Forester, Adrianne Widaman, Kevin D. Laugero

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Chronic stress and over-activity in the hypothalamic–pituitary–adrenal (HPA) axis may link breakfast skipping and poor cardiometabolic health. Missing the first major meal of the day in rodents prolongs elevated circulating corticosterone at a time when it's normally decreasing. To extend these findings to humans, we hypothesized that habitual breakfast skippers would display a similar pattern of circulating cortisol and alterations in meal and stress-induced cortisol reactions. Normal weight to obese women aged 18–45 years old who were strictly defined as either breakfast skippers (n = 30) or breakfast eaters (n = 35) were invited to participate in our study. Normal …