Biochemistry, Biophysics, and Structural Biology Commons^™

The Crosstalk Between Human Fatty Acid Transport Protein 1 And Fatty Acid Transport Protein 4, Zhe Yuan

Department of Biochemistry: Dissertations, Theses, and Student Research

Fatty acid transport proteins (FATPs) provide pivotal roles in fatty acid transport and activation and thus are crucial for overall fatty acid homeostasis. Peroxisome Proliferators Activated Receptors (PPARs) are important transcription factors, which control many genes that govern lipid metabolism.

Using 293 T-REx cell lines that stably express FATP1 or FATP4 from a tetracycline-inducible promoter, this work evaluated gene expression of key genes involved in fatty acid metabolism using QPCR, protein expression of FATP1 and FATP4 using Western blots, and fatty acid transport to address the roles of these two FATP isoforms in fatty acid homeostasis. This work found that …

Iron Insufficiency Compromises Motor Neurons And Their Mitochondrial Function In Irp2-Null Mice, Suh Young Jeong, Daniel R. Crooks, Hayden Wilson-Ollivierre, Manik C. Ghosh, Rachid Sougrat, Jaekwon Lee, Sharon Cooperman, James B. Mitchell, Carole Beaumont, Tracey A. Rouault

Department of Biochemistry: Faculty Publications

Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2), which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 …

Antagonistic Effects Of Cellular Poly(C) Binding Proteins On Vesicular Stomatitis Virus Gene Expression, Phat X. Dinh, Lalit Beura, Debasis Panda, Anshuman Das, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Immunoprecipitation and subsequent mass spectrometry analysis of the cellular proteins from cells expressing the vesicular stomatitis virus (VSV) P protein identified the poly(C) binding protein 2 (PCBP2) as one of the P protein-interacting proteins. To investigate the role of PCBP2 in the viral life cycle, we examined the effects of depletion or overexpression of this protein on VSV growth. Small interfering RNA-mediated silencing of PCBP2 promoted VSV replication. Conversely, overexpression of PCBP2 in transfected cells suppressed VSV growth. Further studies revealed that PCBP2 negatively regulates overall viral mRNA accumulation and subsequent genome replication. Coimmunoprecipitation and immunofluorescence microscopic studies showed that …

Acute Fatty Liver Of Pregnancy: An Update On Mechanisms, Sathish Kumar Natarajan, Kavitha R. Thangaraj, Ashish Goel, C. E. Eapen, K. A. Balasubramanian, Anup Ramachandran

School of Veterinary and Biomedical Sciences: Faculty Publications

Acute fatty liver of pregnancy (AFLP), characterized by hepatic microvesicular steatosis, is a sudden catastrophic illness occurring almost exclusively in the third trimester of pregnancy. Defective fatty acid oxidation in the fetus has been shown to be associated with this disease. Since the placenta has the same genetic makeup as the fetus and as AFLP patients generally recover following delivery, we hypothesized that the placenta might be involved in pathogenesis of this disease. In an animal model of hepatic microvesicular steatosis (using sodium valproate), we found that microvesicular steatosis results in mitochondrial structural alterations and oxidative stress in subcellular organelles …

Remarkable Features Of The Hotdog-Fold Thioesterases Involved In Phylloquinone (Vitamin K1) Biosynthesis, Joshua R. Widhalm

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Phylloquinone (vitamin K₁) is a bipartite molecule, consisting of a naphthoquinone ring attached to a phytyl side chain, that is synthesized by plants and certain cyanobacteria to serve as an electron carrier in photosystem I. The coupling of the ring and isoprenyl moieties relies on the cleavage of the CoA-thioester linkage with 1,4-dihydroxy-2- naphthoate (DHNA). It has long been a mystery if this hydrolysis is an enzymatic or chemical process. Using comparative genomics, protein biochemistry, genetics and metabolic profiling, we identified a cyanobacterial thioesterase responsible for the in vivo hydrolysis of DHNA-CoA. This enzyme bears a signature domain …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …

Glutaredoxin 2 Prevents H2o2-Induced Cell Apoptosis By Protecting Complex I Activity In The Mitochondria, Hongli Wu, Kuiyi Xing, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Glutaredoxin 2 (Grx2) belongs to the oxidoreductase family and is an isozyme of glutaredoxin 1 (Grx1) present in the mitochondria, however its function is not well understood. The purpose of this study is to evaluate the potential anti-apoptotic function of Grx2 by examining its ability to protect complex I in the mitochondrial electron transport system using human lens epithelial cells as a model. We found that cells treated with 200 μM hydrogen peroxide (H2O2) for 24 h exhibited decreased viability and became apoptotic with corresponding Bax up-regulation, Bcl-2 down-regulation, caspase 3 activation and mitochondrial cytochrome c leakage. Grx2 over-expression (OE) …

Regulation Of Cytosolic Phospholipase A2 (Cpla2) And Its Association With Cell Proliferation In Human Lens Epithelial Cells, Yin Wang, Kui-Yi Xing, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. To investigate the molecular mechanism for cytosolic phospholipase A2 (cPLA2) regulation and its association to platelet-derived growth factor (PDGF)-induced cell proliferation.

METHODS. cPLA2 was examined using human lens epithelial (HLE) B3 cells. Reactive oxygen species (ROS) generation induced by PDGF was analyzed by luminescence assay. Cell proliferation was measured by cell counting and by BrdU assay. Human cPLA2 gene was cloned via RT-PCR followed by sitedirected mutagenesis to construct HLE B3 cells expressing either inactive cPLA2 enzyme with S228A mutation (S228A), or cPLA2 truncated at the calcium-binding C2 domain (C2D). Activity of cPLA2 was measured by arachidonic acid (AA) …

Characterization Of Rnai-Defective Mutants—Mut13-2 And Mut20—In Chlamydomonas Reinhardtii, Arit Ghosh

School of Biological Sciences: Dissertations, Theses, and Student Research

RNA interference (RNAi) is a highly conserved and sequence-specific process for regulation of gene expression. At the heart of the RNAi machinery lie 21-24 nt small non-coding RNA molecules which are able to downregulate the expression of cognate sequences, by causing degradation or translational repression of mRNAs. These noncoding RNAs act via the effector RNA-induced silencing complex (RISC), which includes core proteins such as the Argonautes (AGOs). Two Chlamydomonas reinhardtii RNAi-defective mutants, Mut13-2 and Mut20, show deletions of various domains of the Tudor Staphylococcal Nuclease 1 (TSN1) gene. TSN1 has already been recognized as a component of the RNA-induced silencing …

Sphingolipids Containing Very-Long-Chain Fatty Acids Define A Secretory Pathway For Specific Polar Plasma Membrane Protein Targeting In Arabidopsis, Jennifer E. Markham, Diana Molino, Lionel Gissot, Yannick Bellec, Kian Hématy, Jessica Marion, Katia Belcram, Jean-Christophe Palauqui, Béatrice Satiat-Jeunemaître, Jean-Denis Faure

Department of Biochemistry: Faculty Publications

Sphingolipids are a class of structural membrane lipids involved in membrane trafficking and cell polarity. Functional analysis of the ceramide synthase family in Arabidopsis thaliana demonstrates the existence of two activities selective for the length of the acyl chains. Very-long-acyl-chain (C > 18 carbons) but not long-chain sphingolipids are essential for plant development. Reduction of very-long-chain fatty acid sphingolipid levels leads in particular to auxin-dependent inhibition of lateral root emergence that is associated with selective aggregation of the plasma membrane auxin carriers AUX1 and PIN1 in the cytosol. Defective targeting of polar auxin carriers is characterized by specific aggregation of Rab-A2a– …

Immune Evasion Of Porcine Reproductive And Respiratory Syndrome Virus Through Glycan Shielding Involves Both Glycoprotein 5 As Well As Glycoprotein 3, Hiep Vu, Byungjoon Kwon, Kyoung-Jin Yoon, William W. Laegreid, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Passive administration of porcine reproductive and respiratory syndrome virus (PRRSV) neutralizing antibodies (NAbs) can effectively protect pigs against PRRSV infection. However, after PRRSV infection, pigs typically develop a weak and deferred NAb response. One major reason for such a meager NAb response is the phenomenon of glycan shielding involving GP5, a major glycoprotein carrying one major neutralizing epitope. We describe here a type II PRRSV field isolate (PRRSV-01) that is highly susceptible to neutralization and induces an atypically rapid, robust NAb response in vivo. Sequence analysis shows that PRRSV-01 lacks two N-glycosylation sites, normally present in wild-type (wt) PRRSV strains, …

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results.  In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks.  Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …

Functional Studies Of Human Cellular Detoxification Enzymes, Melanie Neely Willis

Department of Biochemistry: Dissertations, Theses, and Student Research

Cellular detoxification allows for the maintenance of cellular homeostasis and prevention of abnormal cell growth by clearing harmful xenobiotics and endobiotics. After oxygenation by phase I enzymes, phase II enzymes such as glucuronosyltransferases and glutathione-s-transferases conjugate a small molecule to the compound, marking it for subsequent export. Many up-stream enzymes are also essential to cellular detoxification by supplying the small compounds for conjugation. These up-stream enzymes include UDP-glucose dehydrogenase, which synthesizes UDP-glucuronate, and glutamate cysteine ligase, which catalyzes the first and rate-limiting step in the synthesis of glutathione.
UDP-glucose dehydrogenase (UGDH) is an important enzyme in human development and in …

Molecular Structures Of Prrsv That Contribute To Prrsv Protective Immunity, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

One of the objectives of the proposal is to delineate the regions of the two glycoproteins (GP2 and GP4) of PRRSV that interact with CD163. Other objectives of the proposal are to generate antibodies to these small regions of the glycoproteins as well as to the full-length proteins for future studies to determine if any of these antibodies possess PRRSV neutralizing activity.

To carry out the studies in the proposed objectives, we generated a series of mutants of GP2 as well as GP4 proteins in which various regions were specifically removed by manipulating the plasmids encoding these proteins. We then …

Transformation Of Fusarium Verticillioides With A Polyketide Gene Cluster Isolated From A Fungal Endophyte Activates The Biosynthesis Of Fusaric Acid, Yunxuan Xie, Wei Zhang, Yaoyao Li, Mingzi Wang, Ronald Cerny, Yue Shen, Liangcheng Du

Liangcheng Du Publications

A large number of bioactive natural products have been isolated from plant endophytic fungi. However, molecular mechanisms for the biosynthesis of these metabolites have lagged behind because genetic and biochemical studies are difficult to perform within many of the endophytes. In this work, we describe our attempt to express a putative mycoepoxydiene (MED) biosynthetic gene cluster in Fusarium verticillioides, which has a well-developed genetic system for the study fungal polyketide biosynthesis. MED was isolated from Phomopsis sp. A123, a fungal endophyte of the mangrove plant, Kandelia candel. It has several unusual structural features and interesting biological activities. Integration of …

Low Levels Of Hydrogen Peroxide Stimulate Corneal Epithelial Cell Adhesion, Migration, And Wound Healing, Qing Pan, Wen-Ya Qiu, Ya-Nan Huo, Yu-Feng Yao, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. Intracellular reactive oxygen species have been reported to associate with growth factor and integrin signalings in promoting cell adhesion in many cell types. This study is to explore if exogenous H2O2 at low levels can be beneficial to cell adhesion, migration, and wound healing.

METHODS. Primary rabbit corneal epithelial cells treated with 0–70 M H2O2 were tested for viability by MTT assay, adhesion by centrifugation assay, focal contacts of vinculin and F-actin by immunofluorescence, activated Src(pY416), EGF receptor (pY845), vinculin(pY1065), FAK(pY397), and FAK(pY576) by immunoblotting. Cell migration was examined with 0–50 M H2O2 using the scratch wound technique. Corneal …

Sphingolipids In The Root Play An Important Role In Regulating The Leaf Ionome In Arabidopsis Thaliana, Dai-Yin Chao, Kenneth Gable, Ming Chen, Ivan Baxter, Charles R. Dietrich, Edgar B. Cahoon, Mary Lou Guerinot, Brett Lahner, Shiyu Lu, Jennifer E. Markham, Joe Morrissey, Gongshe Han, Sita Gupta, Jeffrey M. Harmon, Jan G. Jaworski, Teresa M. Dunn, David E. Salt

Department of Biochemistry: Faculty Publications

Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10D mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B …

Mne1 Is A Novel Component Of The Mitochondrial Splicing Apparatus Responsible For Processing Of A Cox1 Group I Intron In Yeast, Talina Watts, Oleh Khalimonchuk, Rachel Z. Wolf, Edward M. Turk, Georg Mohr, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Saccharomyces cerevisiae cells lacking Mne1 are deficient in

intron splicing in the gene encoding the Cox1 subunit of cytochrome

oxidase but contain wild-type levels of the bc1 complex.

Thus, Mne1 has no role in splicing of COB introns or expression

of the COB gene. Northern experiments suggest that splicing of

the COX1 aI5β intron is dependent on Mne1 in addition to the

previously known Mrs1, Mss116, Pet54, and Suv3 factors. Processing

of the aI5_ intron is similarly impaired in mne1∆ and

mrs1∆ cells and overexpression of Mrs1 partially restores the

respiratory function of mne1∆ cells. Mrs1 …

Roles Of The 15-Kda Selenoprotein (Sep15) In Redox Homeostasis And Cataract Development Revealed By The Analysis Of Sep 15 Knockout Mice, Marina V. Kasaikina, Dmitri E. Fomenko, Vyacheslav M. Labunskyy, Salil A. Lachke, Wenya Qiu, Juliet A. Moncaster, Jie Zhang, Mark W. Wojnarowicz, Sathish Kumar Natarajan, Mikalai I. Malinouski, Ulrich Schweizer, Petra A. Tsuji, Bradley A. Carlson, Richard L. Maas, Marjorie F. Lou, Lee E. Goldstein, Dolph L. Hatfield, Vadim N. Gladyshev

School of Veterinary and Biomedical Sciences: Faculty Publications

The 15-kDa selenoprotein (Sep15) is a thioredoxin-like, endoplasmic reticulum-resident protein involved in the quality control of glycoprotein folding through its interaction with UDP-glucose:glycoprotein glucosyltransferase. Expression of Sep15 is regulated by dietary selenium and the unfolded protein response, but its specific function is not known. In this study, we developed and characterized Sep15 KO mice by targeted removal of exon 2 of the Sep15 gene coding for the cysteinerich UDP-glucose:glycoprotein glucosyltransferase-binding domain. These KO mice synthesized a mutant mRNA, but the shortened protein product could be detected neither in tissues nor in Sep15 KO embryonic fibroblasts. Sep15 KO mice were viable …

Differential Transcription Of Cytochrome P450s And Glutathione S Transferases In Ddt-Susceptible And -Resistant Drosophila Melanogaster Strains In Response To Ddt And Oxidative Stress, Lijie Sun, Brandi Schemerhorn, Amber Jannasch, Kent R. Walters Jr., Jiri Adamec, William M. Muir, Barry R. Pittendrigh

Department of Biochemistry: Faculty Publications

Metabolic DDT resistance in Drosophila melanogaster has previously been associated with constitutive over-transcription of cytochrome P450s. Increased P450 activity has also been associated with increased oxidative stress. In contrast, over-transcription of glutathione S transferases (GSTs) has been associated with resistance to oxidative stress. However, little is known in regards to the impact of xenobiotics on induction of P450s and GSTs and if there exist differences in inducibility between the pesticide susceptible and resistant strains. Thus, we investigated the transcriptional expression of GSTs and P450s in DDT resistant (Wisconsin) and susceptible (Canton-S) Drosophila strains in response to …

Thiol Peroxidases Mediate Specific Genome-Wide Regulation Of Gene Expression In Response To Hydrogen Peroxide, Dmitri E. Fomenko, Ahmet Koc, Natalia Agisheva, Michael Jacobsen, Alaattin Kaya, Mikalai Malinouski, Julian C. Rutherford, Kam-Leung Siu, Dong-Yan Jin, Dennis R. Winge, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Hydrogen peroxide is thought to regulate cellular processes by direct oxidation of numerous cellular proteins, whereas antioxidants, most notably thiol peroxidases, are thought to reduce peroxides and inhibit H₂O₂ response. However, thiol peroxidases have also been implicated in activation of transcription factors and signaling. It remains unclear if these enzymes stimulate or inhibit redox regulation and whether this regulation is widespread or limited to a few cellular components. Herein, we found that Saccharomyces cerevisiae cells lacking all eight thiol peroxidases were viable and withstood redox stresses. They transcriptionally responded to various redox treatments, but were unable to …

Tca Cycle Inactivation In Staphylococcus Aureus Alters Nitric Oxide Production In Raw 264.7 Cells, Chandirasegaran Massilamany, Arunakumar Gangaplara, Donald J. Gardner, James M. Musser, David J. Steffen, Greg A. Somerville, Jay Reddy

Jay Reddy Publications

Inactivation of the Staphylococcus aureus tricarboxylic acid (TCA) cycle delays the resolution of cutaneous ulcers in a mouse soft tissue infection model. In this study, it was observed that cutaneous lesions in mice infected with wild-type or isogenic aconitase mutant S. aureus strains contained comparable inflammatory infiltrates, suggesting the delayed resolution was independent of the recruitment of immune cells. These observations led us to hypothesize that staphylococcal metabolism can modulate the host immune response. Using an in vitro model system involving RAW 264.7 cells, the authors observed that cells cultured with S. aureus aconitase mutant strains produced significantly lower amounts …

Hydrogen Peroxide Probes Directed To Different Cellular Compartments, Mikalai Malinouski, You Zhou, Vsevolod V. Belousov, Dolph L. Hatfield, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Background: Controlled generation and removal of hydrogen peroxide play important roles in cellular redox homeostasis and signaling. We used a hydrogen peroxide biosensor HyPer, targeted to different compartments, to examine these processes in mammalian cells.

Principal Findings: Reversible responses were observed to various redox perturbations and signaling events. HyPer expressed in HEK 293 cells was found to sense low micromolar levels of hydrogen peroxide. When targeted to various cellular compartments, HyPer occurred in the reduced state in the nucleus, cytosol, peroxisomes, mitochondrial intermembrane space and mitochondrial matrix, but low levels of the oxidized form of the biosensor were also observed …

Targeted Deletion Of The Mouse Mitoferrin1 Gene: From Anemia To Protoporphyria, Marie-Berengere Troadec, David Warner, Jared Wallace, Kirk Thomas, Gerald J. Spangrude, John Phillips, Oleh Khalimonchuk, Barry H. Paw, Diane Mcvey Ward, Jerry Kaplan

Department of Biochemistry: Faculty Publications

Mitoferrin1 is 1 of 2 homologous mitochondrial iron transporters and is required for mitochondrial iron delivery in developing erythroid cells. We show that total deletion of Mfrn1 in embryos leads to embryonic lethality. Selective deletion of Mfrn1 in adult hematopoietic tissues leads to severe anemia because of a deficit in erythroblast formation. Deletion of Mfrn1 in hepatocytes has no phenotype or biochemical effect under normal conditions. In the presence of increased porphyrin synthesis, however, deletion of Mfrn1 in hepatocytes results in a decreased ability to convert protoporphyrin IX into heme, leading to protoporphyria, cholestasis, and bridging cirrhosis. Our results show …

Mechanisms Of Decreased Cholesterol Absorption Mediated By Phytosterols In The Intestinal Lumen, Andrew W. Brown

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

Phytosterols and their fatty acyl esters have been known for decades to lower LDL cholesterol, making them powerful nutraceuticals in lowering cardiovascular disease risk. The mechanisms by which phytosterols lower cholesterol, though, have been incompletely characterized. Three studies were executed to examine three aspects of cholesterol and phytosterol interactions in the intestinal lumen. In the first study, the ability of pancreatic cholesterol esterase to hydrolyze phytosterol esters was examined. Pancreatic cholesterol esterase hydrolyzed phytosterol esters, but the rate of hydrolysis proved sensitive to the structures of both the sterol and ester components. In the second study, cholesterol micellarization was challenged …

Carbenoxolone Blocks The Light-Evoked Rise In Intracellular Calcium In Isolated Melanopsin Ganglion Cell Photoreceptors, Jayne R. Bramley, Erin M. Wiles, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Retinal ganglion cells expressing the photopigment melanopsin are intrinsically photosensitive (ipRGCs). These ganglion cell photoreceptors send axons to several central targets involved in a variety of functions. Within the retina ipRGCs provide excitatory drive to dopaminergic amacrine cells via glutamatergic signals and ipRGCs are coupled to widefield GABAergic amacrine cells via gap junctions. However, the extent to which ipRGCs are coupled to other retinal neurons in the ganglion cell layer via gap junctions is unclear. Carbenoxolone, a widely employed gap junction inhibitor, greatly reduces the number of retinal neurons exhibiting non-rod, non-cone mediated light-evoked Ca²⁺ signals suggesting extensive …

Y-Like Retinal Ganglion Cells Innervate The Dorsal Raphe Nucleus In The Mongolian Gerbil (Meriones Unguiculatus), Liju Luan, Chaoran Ren, Benson Wui-Man Lau, Jian Yang, Gary E. Pickard, Kwok-Fai So, Mingliang Pu

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The dorsal raphe nucleus (DRN) of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC) that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells.

Methodology/Principal Findings: The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used …

Challenges And Opportunities For Toxicology In Mexico, Rodrigo Franco, Balam Muñoz

School of Veterinary and Biomedical Sciences: Faculty Publications

We have developed this Special Issue titled “Challenges and Opportunities for Toxicology in Mexico” with the aim to highlight not only the challenges toxicology research faces in Mexico, but also the efforts and drive towards cutting edge research to address them. Altogether, this special issue should be a valuable source of information for all readers with an interest in toxicology and human health.

Mexico is an important economy worldwide and is a major exporter of several supplies and commodities. Because of this, its industry is a source of occupational exposure to several chemical derivatives (Nieusma 2011). The situation of occupational …

Intrinsically Photosensitive Retinal Ganglion Cells, Gary E. Pickard, Patricia J. Sollars

School of Veterinary and Biomedical Sciences: Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light in the absence of all rod and cone photoreceptor input. The existence of these ganglion cell photoreceptors, although predicted from observations scattered over many decades, was not established until it was shown that a novel photopigment, melanopsin, was expressed in retinal ganglion cells of rodents and primates. Phototransduction in mammalian ipRGCs more closely resembles that of invertebrate than vertebrate photoreceptors and appears to be mediated by transient receptor potential channels. In the retina, ipRGCs provide excitatory drive to dopaminergic amacrine cells and ipRGCs are coupled to GABAergic amacrine cells via gap …

Long-Term Clinicopathological Characteristics Of Alpacas Naturally Infected With Bovine Viral Diarrhea Virus Type Ib, D. Bedenice, Edward J. Dubovi, Clayton Kelling, Jamie N Henningson, Christina L. Topliff, N. Parry

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Substantial bovine viral diarrhea virus (BVDV)-related production losses in North American alpaca herds have been associated with BVDV type Ib infection.

Objectives: To classify and differentiate the long-term clinicopathological characteristics of BVDV type Ib infection of al- paca crias, after natural virus exposure. We hypothesized that persistently infected (PI) alpacas specifically demonstrate growth retardation, clinicopathological evidence of opportunistic infections, and early mortality.

Animals: Thirty-five crias naturally exposed to BVDV (18 acute, 3 chronic, 14 PIs), and 19 healthy cohort controls of 5 northeastern alpaca farms were prospectively evaluated over 2 years (September 2005–September 2008).

Methods: Observational cohort-control study.

Results: …