ABSTRACT
Understanding how tropical corals respond to temperatures is important to evaluating their capacity to persist in a warmer future. We studied the common Pacific coral Pocillopora over 44° of latitude, and used populations at three islands with different thermal regimes to compare their responses to temperature using thermal performance curves (TPCs) for respiration and gross photosynthesis. Corals were sampled in the local autumn from Moorea, Guam and Okinawa, where mean±s.d. annual seawater temperature is 28.0±0.9°C, 28.9±0.7°C and 25.1±3.4°C, respectively. TPCs for respiration were similar among latitudes, the thermal optimum (Topt) was above the local maximum temperature at all three islands, and maximum respiration was lowest at Okinawa. TPCs for gross photosynthesis were wider, implying greater thermal eurytopy, with a higher Topt in Moorea versus Guam and Okinawa. Topt was above the maximum temperature in Moorea, but was similar to daily temperatures over 13% of the year in Okinawa and 53% of the year in Guam. There was greater annual variation in daily temperatures in Okinawa than Guam or Moorea, which translated to large variation in the supply of metabolic energy and photosynthetically fixed carbon at higher latitudes. Despite these trends, the differences in TPCs for Pocillopora spp. were not profoundly different across latitudes, reducing the likelihood that populations of these corals could better match their phenotypes to future more extreme temperatures through migration. Any such response would place a premium on high metabolic plasticity and tolerance of large seasonal variations in energy budgets.
Subject(s)
Anthozoa , Photosynthesis , Temperature , Animals , Anthozoa/physiology , Photosynthesis/physiology , Seasons , Seawater/chemistryABSTRACT
A formidable challenge for global change biologists is to predict how natural populations will respond to the emergence of conditions not observed at present, termed novel climates. Popular approaches to predict population vulnerability are based on the expected degree of novelty relative to the amplitude of historical climate fluctuations experienced by a population. Here, we argue that predictions focused on amplitude may be inaccurate because they ignore the predictability of environmental fluctuations in driving patterns of evolution and responses to climate change. To address this disconnect, we review major findings of evolutionary theory demonstrating the conditions under which phenotypic plasticity is likely to evolve in natural populations, and how plasticity decreases population vulnerability to novel environments. We outline key criteria that experimental studies should aim for to effectively test theoretical predictions, while controlling for the degree of climate novelty. We show that such targeted tests of evolutionary theory are rare, with marine systems being overall underrepresented in this venture despite exhibiting unique opportunities to test theory. We conclude that with more robust experimental designs that manipulate both the amplitude and predictability of fluctuations, while controlling for the degree of novelty, we may better predict population vulnerability to climate change.
Subject(s)
Adaptation, Physiological , Biological Evolution , Climate ChangeABSTRACT
Effects of dietary methionine (Met) on pectoralis muscle development and the effect that Met as a nutritional substrate has on protein expression of skeletal muscle cells of pectoralis muscle of chickens were evaluated in this study. Broiler chickens received a common pretest diet up to 21 d of age and were subsequently fed either a low (LM) or high Met (HM) diet (0.41 vs. 0.51% of diet) from 21 to 42 d of age. Dietary deficiency was shown in vivo judging by the depression in breast meat weight and yield when broilers were fed the LM diet. Global protein expression was analyzed by quantitative high-performance liquid chromatography nanospray ionization tandem mass spectrometry. Up- and downregulated proteins were analyzed via Ingenuity Pathways Analysis to identify the metabolic pathways affected. Four canonical pathways related to muscle development were identified as being differentially regulated between LM- and HM-fed chickens. These pathways included the citrate cycle and calcium, actin cytoskeleton, and clathrin-mediated endocytosis signaling. The HM diet may have allowed for increased muscle growth by an increased availability of nutrients to muscle cells. Although the Met supplementation was associated with enhanced breast muscle growth, contraction fiber concentrations in muscles decreased and were associated with a lower calcium transportation rate and sensitivity and with a lower energy supply. It is further suggested that increased muscle protein deposition, that was induced by Met supplementation, may have been largely due to sarcoplasmic rather myofibrillar hypertrophy.
Subject(s)
Chickens , Gene Expression Regulation/drug effects , Methionine/pharmacology , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Actin Cytoskeleton/physiology , Animal Feed/analysis , Animal Nutritional Physiological Phenomena , Animals , Calcium Signaling/physiology , Citrates/metabolism , Clathrin/metabolism , Diet/veterinary , Dietary Supplements , Gene Expression Profiling , Male , Methionine/administration & dosage , Muscle Proteins/geneticsABSTRACT
The equine genome sequence enables the use of high-throughput genomic technologies in equine research, but accurate identification of expressed gene products and interpreting their biological relevance require additional structural and functional genome annotation. Here, we employ the equine genome sequence to identify predicted and known proteins using proteomics and model these proteins into biological pathways, identifying 582 proteins in normal cell-free equine bronchoalveolar lavage fluid (BALF). We improved structural and functional annotation by directly confirming the in vivo expression of 558 (96%) proteins, which were computationally predicted previously, and adding Gene Ontology (GO) annotations for 174 proteins, 108 of which lacked functional annotation. Bronchoalveolar lavage is commonly used to investigate equine respiratory disease, leading us to model the associated proteome and its biological functions. Modelling of protein functions using Ingenuity Pathway Analysis identified carbohydrate metabolism, cell-to-cell signalling, cellular function, inflammatory response, organ morphology, lipid metabolism and cellular movement as key biological processes in normal equine BALF. Comparative modelling of protein functions in normal cell-free bronchoalveolar lavage proteomes from horse, human, and mouse, performed by grouping GO terms sharing common ancestor terms, confirms conservation of functions across species. Ninety-one of 92 human GO categories and 105 of 109 mouse GO categories were conserved in the horse. Our approach confirms the utility of the equine genome sequence to characterize protein networks without antibodies or mRNA quantification, highlights the need for continued structural and functional annotation of the equine genome and provides a framework for equine researchers to aid in the annotation effort.
Subject(s)
Bronchoalveolar Lavage Fluid/chemistry , Genome/genetics , Horses/genetics , Molecular Sequence Annotation/methods , Proteins/genetics , Animals , Humans , Mass Spectrometry , Mice , Models, Biological , Proteins/analysis , Proteins/physiology , Proteomics/methodsABSTRACT
The chicken genome is sequenced and this, together with microarray and other functional genomics technologies, makes post-genomic research possible in the chicken. At this time, however, such research is hindered by a lack of genomic structural and functional annotations. Bio-ontologies have been developed for different annotation requirements, as well as to facilitate data sharing and computational analysis, but these are not yet optimally utilized in the chicken. Here we discuss genomic annotation and bio-ontologies. We focus specifically on the Gene Ontology (GO), chicken GO annotations and how these can facilitate functional genomics in the chicken. The GO is the most developed and widely used bio-ontology. It is the de facto standard for functional annotation. Despite its critical importance in analyzing microarray and other functional genomics data, relatively few chicken gene products have any GO annotation. When these are available, the average quality of chicken gene products annotations (defined using evidence code weight and annotation depth) is much less than in mouse. Moreover, tools allowing chicken researchers to easily and rapidly use the GO are either lacking or hard to use. To address all of these problems we developed ChickGO and AgBase. Chicken GO annotations are provided by complementary work at MSU-AgBase and EBI-GOA. The GO tools pipeline at AgBase uses GO to derive functional and biological significance from microarray and other functional genomics data. Not only will improved genomic annotation and tools to use these annotations benefit the chicken research community but they will also facilitate research in other avian species and comparative genomics.
Subject(s)
Biology/methods , Genomics/methods , Animals , Base Sequence , Genome/genetics , Humans , InternetABSTRACT
Since the sequencing of the genome and the development of high-throughput tools for the exploration of functional elements of the genome, the chicken has reached model organism status. Functional genomics focuses on understanding the function and regulation of genes and gene products on a global or genome-wide scale. Systems biology attempts to integrate functional information derived from multiple high-content data sets into a holistic view of all biological processes within a cell or organism. Generation of a large collection ( approximately 600K) of chicken expressed sequence tags, representing most tissues and developmental stages, has enabled the construction of high-density microarrays for transcriptional profiling. Comprehensive analysis of this large expressed sequence tag collection and a set of approximately 20K full-length cDNA sequences indicate that the transcriptome of the chicken represents approximately 20,000 genes. Furthermore, comparative analyses of these sequences have facilitated functional annotation of the genome and the creation of several bioinformatic resources for the chicken. Recently, about 20 papers have been published on transcriptional profiling with DNA microarrays in chicken tissues under various conditions. Proteomics is another powerful high-throughput tool currently used for examining the dynamics of protein expression in chicken tissues and fluids. Computational analyses of the chicken genome are providing new insight into the evolution of gene families in birds and other organisms. Abundant functional genomic resources now support large-scale analyses in the chicken and will facilitate identification of transcriptional mechanisms, gene networks, and metabolic or regulatory pathways that will ultimately determine the phenotype of the bird. New technologies such as marker-assisted selection, transgenics, and RNA interference offer the opportunity to modify the phenotype of the chicken to fit defined production goals. This review focuses on functional genomics in the chicken and provides a road map for large-scale exploration of the chicken genome.
Subject(s)
Chickens/genetics , Genomics , Models, Animal , Animals , Gene Expression RegulationABSTRACT
Maternal antibodies are transferred from hens to the chicks via the egg. To gain insight into maternal antibody transfer and endogenous production of antibodies in broiler chicks, total IgY, IgA, IgM, as well as anti-Newcastle disease virus (NDV) and anti-infectious bronchitis (IBV) antibody levels were examined in the dams' plasma, egg yolks, egg whites, and chicks' plasma on d 3, 7, 14, and 21. Blood was collected from 39-wk-old breeder hens (line 1, n = 17; line 2, n = 21). Fertile eggs were used for antibody extraction from the egg yolks and egg whites (4 to 5 eggs/dam) and for hatching. Unvaccinated chicks (4 to 5 chicks/dam) were reared in a HEPA-filtered room and were bled on d 3, 7, 14 and 21. Based on ELISA methods, plasma levels of IgY and IgM were higher (P < 0.0001), and those of IgA were similar (P = 0.31), in line 2 compared with line 1. Egg yolk IgY and IgA, as well as egg white IgY, IgA, and IgM levels were higher in line 2 compared with line 1 (P < 0.0001). Independent of line of chicken, the percentage dam-to-chick (3 d) plasma transfer of IgY was estimated to be approximately 30%, with that for IgM and IgA less than 1%. Chicks synthesized IgM first, followed by IgA and IgY. Anti-NDV and anti-IBV antibodies were detected in the dams' plasma, egg yolks, and in the chicks' plasma on d 3 and 7, with line 2 having higher anti-IBV and lower anti-NDV levels than line 1 in all samples (P < 0.0001). In summary, IgY levels, total or antigen-specific, in the dams' plasma or eggs were found to be a direct indicator of maternal antibody transfer to the chicks' circulation, with an expected percentage transfer of approximately 30%. This knowledge, together with the observed time course of endogenous antibody production in broiler chicks, may find direct application in formulating strategies for protecting chicks, especially during the first few weeks of age when their immune system is not yet fully functional.
Subject(s)
Antibodies, Viral/analysis , Chickens/immunology , Coronavirus Infections/veterinary , Immunity, Maternally-Acquired/immunology , Infectious bronchitis virus/immunology , Newcastle Disease/immunology , Poultry Diseases/immunology , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , Coronavirus Infections/blood , Coronavirus Infections/immunology , Female , Immunoglobulin A/analysis , Immunoglobulin M/analysis , Immunoglobulins/analysis , Newcastle Disease/blood , Poultry Diseases/bloodABSTRACT
Placental HIV infections frequently result in infected babies or miscarriage. Aberrant placental cytokine expression during HIV infections may facilitate transplacental viral transmission or pregnancy perturbation. The feline immunodeficiency virus (FIV)-infected cat is a model for HIV infections due to similarities in biology and clinical disease. The purpose of this study was to evaluate placental immunomodulator expression and reproductive outcome using the FIV-infected cat model. Kittens were cesarean delivered from FIV-B-2542-infected and control queens near term; placental and fetal tissues were collected. Real-time RT-PCR was used to measure expression of representative placental Th1 cytokines, interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma), a Th2 cytokine, IL-10, and chemokine receptor CXCR4. On average, control queens delivered 3.8 kittens/litter; 1 of 31 kittens (3.2%) was non-viable. FIV-infected queens produced 2.7 kittens/litter; 15 of 25 concepti (60%) were non-viable. FIV was detected in 14 of 15 placentas (93%) and 21 of 22 fetuses (95%) using PCR. Placental immunomodulator expression did not differ significantly when placentas from infected cats were compared to those of control cats. However, elevated expression of Th1 cytokines and increased Th1/Th2 ratios (IL-1beta/IL-10) occurred in placentas from resorptions. Therefore, increased placental Th1 cytokine expression was associated with pregnancy failure in the FIV-infected cat.
Subject(s)
Embryo Loss/immunology , Feline Acquired Immunodeficiency Syndrome/immunology , Fetal Resorption/immunology , Lentivirus Infections/immunology , Placenta/immunology , Pregnancy Complications, Infectious/immunology , Animals , Cat Diseases , Cats , Cells, Cultured , Cytokines/biosynthesis , Cytokines/genetics , DNA, Viral , Disease Models, Animal , Embryo Loss/metabolism , Embryo Loss/virology , Feline Acquired Immunodeficiency Syndrome/metabolism , Feline Acquired Immunodeficiency Syndrome/transmission , Female , Fetal Resorption/metabolism , Fetal Resorption/virology , Immunodeficiency Virus, Feline , Lentivirus Infections/metabolism , Placenta/metabolism , Placenta/virology , Pregnancy , Pregnancy Complications, Infectious/metabolism , Pregnancy Complications, Infectious/virology , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Specific Pathogen-Free OrganismsABSTRACT
The Harderian gland (HG), a sero-mucous secreting organ in the eye orbit, has long been recognized as immunologically important in chickens. During experimentation to characterize immune components of the gland, proteomics analysis revealed the presence of hematopoietic prostaglandin D synthase (H-PGDS). Extraction of total RNA followed by RT-PCR produced cDNA of 597 base pairs. DNA sequencing revealed nucleic acid and predicted amino acid sequences that were 99% aligned with the one published sequence for chicken H-PGDS of the spleen. Alignment with murine, rat, and human H-PGDS were 69, 69, and 66%, respectively. Ocular vaccination of chickens with a Newcastle Disease/Infectious Bronchitis vaccine (Mass.-Ark. Strain) induced an increase in H-PGDS expression determined by real-time PCR. Furthermore, immunohistochemistry of frozen HG sections showed positive stained cells for both H-PGDS and mast cell tryptase in the sub-epithelial cell layers of the HG ducts. Based on the potent vasoactive role of PGD(2), it appears that the chicken HG is a site of active mucosal immunity partially mediated by PGD(2) synthesized by H-PGDS in the gland.
Subject(s)
Harderian Gland/enzymology , Intramolecular Oxidoreductases/metabolism , Amino Acid Sequence , Animals , Chickens , Coronavirus Infections/immunology , Gene Expression Regulation, Enzymologic , Harderian Gland/cytology , Intramolecular Oxidoreductases/genetics , Lipocalins , Molecular Sequence Data , Newcastle Disease/immunology , Sequence Alignment , Sequence Homology, Amino Acid , Viral Vaccines/immunologyABSTRACT
Dietary Lys needs for chicks were studied. A titration diet consisting of progressive amounts of dietary Lys from 0.95% up to 1.40% was fed to broiler chicks from 0 to 18 d of age. Optimal dietary Lys level was calculated using regression analysis. Body weight gain and feed conversion were maximized at Lys levels of 1.24% (1.10% digestible) and 1.27% (1.13% digestible) of diet, respectively. Blood samples were then collected from 2 groups: birds fed the lowest Lys level and birds fed dietary Lys nearest the determined requirement level (1.25% Lys). Plasma was analyzed for protein spectra via mass spectrometry and then classified by their functional characteristics. The number of proteins was similar between the 2 samples, but there was a tendency toward increased peptides for specific proteins in plasma from chicks fed adequate Lys levels. Furthermore, after these proteins were classified, more muscle-related proteins were found in plasma samples of birds fed Lys-adequate diets. It would appear that an individual dietary amino acid deficiency does not necessarily translate into decreasing protein synthesis proportionate to body weight, but rather significant changes may be occurring within the types of proteins undergoing anabolism. In conclusion, results herein illustrate the potential for using functional genomics in nutritionally related responses of poultry.
Subject(s)
Amino Acids/administration & dosage , Animal Nutritional Physiological Phenomena , Chickens/blood , Chickens/growth & development , Diet , Proteome/analysis , Animals , Blood Proteins/analysis , Dietary Proteins/administration & dosage , Lysine/administration & dosage , Male , Muscle Proteins/blood , Nutritional RequirementsABSTRACT
(13)C-edited proton nuclear magnetic resonance (NMR) spectroscopy was used to follow enrichment of glutamate C3 and C4 with a temporal resolution of approximately 20 s in mouse hearts perfused with (13)C-enriched substrates. A fit of the NMR data to a kinetic model of the tricarboxylic acid (TCA) cycle and related exchange reactions yielded TCA cycle (V(tca)) and exchange (V(x)) fluxes between alpha-ketoglutarate and glutamate. These fluxes were substrate-dependent and decreased in the order acetate (V(tca)=14.1 micromol g(-1) min(-1); V(x)=26.5 micromol g(-1) min(-1))>octanoate (V(tca)=6.0 micromol g(-1) min(-1); V(x)=16.1 micromol g(-1) min(-1))>lactate (V(tca)=4.2 micromol g(-1) min(-1); V(x)=6.3 micromol g(-1) min(-1)).
Subject(s)
Citric Acid Cycle/physiology , Glutamic Acid/analysis , Magnetic Resonance Spectroscopy/methods , Myocardium/metabolism , Animals , Female , Glutamic Acid/metabolism , In Vitro Techniques , Ketoglutaric Acids/metabolism , Mice , Oxygen Consumption , Perfusion , Sensitivity and SpecificityABSTRACT
A novel flow cytometric technique was developed to determine the absolute numbers of leukocytes of specific phenotypes in whole blood from two lines of inbred chickens (line 7(2) and line 6(1)). This single step method is rapid, accurate, repeatable, can be used in the presence of nucleated erythrocytes and addresses the problems encountered when electronically counting the numbers of leukocytes in specific subpopulations in the blood of non-mammalian species. It is superior to previous methods in that (1) peripheral blood leukocytes (PBL) do not need to be separated by density gradient centrifugation, (2) erythrocyte lysis is not necessary and (3) absolute numbers of specific phenotypes of cells are determined directly. A standard volume of diluted whole blood was added to a standard number of fluorescent beads before incubation with fluorescently-conjugated monoclonal antibodies recognising specific PBL surface antigens. Samples were analysed by flow cytometry and electronic gates were set to count a standard number of beads and the concomitant fluorescently-labelled cells. Absolute numbers of B, CD4+ and CD8+ PBL were determined. Since the bead fluorescence is constant, it was also possible to measure relative MHC class I expression using fluorescence intensity. In both lines of chickens absolute numbers of all of the phenotypes of PBL measured increased with age. Although line 7(2) chickens had greater numbers of B, CD4+, and CD8+ PBL than line 6(1) chickens, there was no significant difference in the CD4+:CD8+ PBL ratios, the T:B PBL ratios or relative MHC class I expression between the two lines. Relative MHC class I expression increased with age in both lines.
Subject(s)
Chickens/blood , Flow Cytometry/methods , Leukocyte Count , Age Factors , Animals , CD4 Lymphocyte Count , Histocompatibility Antigens Class I/analysis , T-Lymphocyte SubsetsABSTRACT
A duplex polymerase chain reaction (PCR) was developed to measure Marek's disease virus (MDV) load in two subpopulations of Marek's disease (MD) lymphoma cells from chickens. PCR primers were designed using the sequence of the MDV-ICP4 gene and the chicken IFNgamma gene. Each set of primers was present in the same reaction tube so that the 327 bp ICP4 product and the 420 bp IFNgamma product were co-amplified. Two different fluorescent dyes were used to 5'-end label one PCR primer of each pair to distinguish the IFNgamma and ICP4 products by colour. The IFNgamma PCR product was used as an internal standard enabling comparisons of MDV-ICP4 products between different samples. Neither duplex PCR product was preferentially amplified and both reactions were in their exponential phases when stopped. The products could be distinguished by both size and colour. MD lymphoma cells were taken ex vivo and separated on the basis of expressing a novel host surface antigen recognised by the monoclonal antibody AV37. AV37 + lymphoma cells had greater MDV-loads than AV37 lymphoma cells. The principles used here should be applicable to any cell phenotype and/or cell-associated DNA virus.
Subject(s)
Herpesvirus 2, Gallid/isolation & purification , Polymerase Chain Reaction/methods , Animals , Cell Line, Transformed , Chickens , Herpesvirus 2, Gallid/genetics , Lymphoma , Tumor Cells, Cultured , Viral LoadABSTRACT
The entire chicken genome sequence will be available by the time this review is in press. Chickens will be the first production animal species to enter the "postgenomic era." This fundamental structural genomics achievement allows, for the first time, complete functional genomics approaches for understanding the molecular basis of chicken normo- and pathophysiology. The functional genomics paradigm, which contrasts with classical functional genetic investigations of one gene (or few) in isolation, is the systematic holistic genetic analyses of biological systems in defined contexts. Context-dependent gene interactions are the fundamental mechanics of all life. Functional genomics uses high-throughput large-scale experimental methods combined with statistical and computational analyses. Projects with expressed sequence tags in chickens have already allowed the creation of cDNA microarrays for large-scale context-dependant mRNA analysis (transcriptomics). However, proteins are the functional units of almost all biological processes, and protein expression very often bears no correlation to mRNA expression. Proteomics, a discipline within functional genomics, is the context-defined analysis of complete complements of proteins. Proteomics bridges the "sequence-to-phenotype gap;" it complements structural and other functional genomics approaches. Proteomics requires high capital investment but has ubiquitous biological applications. Although currently the fastest-growing human biomedical discipline, new paradigms may need to be established for production animal proteomics research. The prospective promise and potential pitfalls of using proteomics approaches to improve poultry pathogen control will be specifically highlighted. The first stage of our recently established proteomics program is global protein profiling to identify differentially expressed proteins in the context of the commercially important pathogens. Our trials and tribulations in establishing our proteomics program, as well some of our initial data to understand chicken immune system function, will be discussed.
Subject(s)
Chickens/genetics , Chickens/immunology , Poultry Diseases/immunology , Proteomics/methods , Animals , Computational Biology , Electrophoresis, Polyacrylamide Gel , Genome , Poultry Diseases/genetics , Proteins/genetics , Proteins/isolation & purification , Proteomics/trends , PubMedABSTRACT
Broilers fed diets with reduced amino acid levels may be limiting in isoleucine. Because research addressing daily Ile needs for broiler immunity is sparse, Ile responses for immunity in female broilers were evaluated in 2 experiments in broilers from 30 to 42 d of age. Cellular and humoral immunity were evaluated in diets limiting in Ile and diets varying in Ile from deficient to adequate. Pen was the experimental unit in both experiments. Treatments in experiment 1 consisted of 2 levels of Ile (0.42 vs. 0.72% total of diet) and 3 strains of broilers, Arbor Acres+, Ross 508, Ross 708 (6 treatments; 5 pens each). In experiment 1, measurements consisted of: a cutaneous basophil hypersensitivity test to phytohemagglutinin-P (PHA-P) on d 37 and 38; cell quantification of CD4+, CD8+, and BU-1+ lymphocytes at d 41 and 42; and relative immune organ weights at 42 d. No Ile x strain interaction occurred. Feeding an Ile-deficient diet to broilers suppressed the cell mediated response to PHA-P, and reduced thymus weight and the percentage of CD8+ T cells. There were no significant differences between strains. In experiment 2, gradations of Ile (0.42, 0.50, 0.58, 0.66, 0.74, and 0.82% total of diet) were fed to one strain (Ross 508) of female broilers (7 pens per diet). A control diet containing 0.70% Ile (6 pens) was compared with an Ile surfeit concentration. Measurements in experiment 2 consisted of a hypersensitivity test to PHA-P on d 35 and 36; a primary antibody response to SRBC from 35 to 42 d; cell quantification of CD8+ alpha, beta, and T cell receptor (TCR)-1 (delta/gamma) lymphocytes on d 41 and 42; and immune organ weights at 42 d. Immunity measurements in birds fed surfeit Ile in the titration diets were equal to birds fed the control diet. A linear response to increasing Ile was obtained for relative bursa, but no Ile quadratic responses were noted for other measurements in experiment 2. Although feeding broilers a diet deficient in Ile suppressed some immune criteria, it does not appear that a marginal Ile deficiency will compromise immunity in growing female broilers.
Subject(s)
Chickens/immunology , Isoleucine/immunology , Isoleucine/pharmacology , Animal Feed , Animals , Antibodies/blood , Diet , Erythrocytes/immunology , Female , Isoleucine/administration & dosage , Lymphoid Tissue/drug effects , Organ Size/drug effects , Phytohemagglutinins/immunology , SheepABSTRACT
The majority of robotic vehicles that can be found today are bound to operations within a single media (i.e. land, air or water). This is very rarely the case when considering locomotive capabilities in natural systems. Utility for small robots often reflects the exact same problem domain as small animals, hence providing numerous avenues for biological inspiration. This paper begins to investigate the various modes of locomotion adopted by different genus groups in multiple media as an initial attempt to determine the compromise in ability adopted by the animals when achieving multi-modal locomotion. A review of current biologically inspired multi-modal robots is also presented. The primary aim of this research is to lay the foundation for a generation of vehicles capable of multi-modal locomotion, allowing ambulatory abilities in more than one media, surpassing current capabilities. By identifying and understanding when natural systems use specific locomotion mechanisms, when they opt for disparate mechanisms for each mode of locomotion rather than using a synergized singular mechanism, and how this affects their capability in each medium, similar combinations can be used as inspiration for future multi-modal biologically inspired robotic platforms.
Subject(s)
Biomimetics/instrumentation , Biomimetics/methods , Gait/physiology , Locomotion/physiology , Models, Biological , Robotics/instrumentation , Robotics/methods , Animals , Equipment Design , HumansABSTRACT
This paper reports the integration of a kinematic model of the human hand during cylindrical grasping, with specific focus on the accurate mapping of thumb movement during grasping motions, and a novel, multi-degree-of-freedom assistive exoskeleton mechanism based on this model. The model includes thumb maximum hyper-extension for grasping large objects (~> 50 mm). The exoskeleton includes a novel four-bar mechanism designed to reproduce natural thumb opposition and a novel synchro-motion pulley mechanism for coordinated finger motion. A computer aided design environment is used to allow the exoskeleton to be rapidly customized to the hand dimensions of a specific patient. Trials comparing the kinematic model to observed data of hand movement show the model to be capable of mapping thumb and finger joint flexion angles during grasping motions. Simulations show the exoskeleton to be capable of reproducing the complex motion of the thumb to oppose the fingers during cylindrical and pinch grip motions.
Subject(s)
Hand/physiology , Robotics/instrumentation , Robotics/methods , Biomechanical Phenomena , Fingers/physiopathology , Humans , Models, Theoretical , Movement/physiology , Thumb/physiologyABSTRACT
Sperm mobility is defined as sperm movement against resistance at body temperature. Although all mobile sperm are motile, not all motile sperm are mobile. Sperm mobility is a primary determinant of male fertility in the chicken. Previous work explained phenotypic variation at the level of the sperm cell and the mitochondrion. The present work was conducted to determine if phenotypic variation could be explained at the level of the proteome using semen donors from lines of chickens selected for low or high sperm mobility. We began by testing the hypothesis that premature mitochondrial failure, and hence sperm immobility, arose from Ca(2+) overloading. The hypothesis was rejected because staining with a cell permeant Ca(2+)-specific dye was not enhanced in the case of low mobility sperm. The likelihood that sperm require little energy before ejaculation and the realization that the mitochondrial permeability transition can be induced by oxidative stress arising from inadequate NADH led to the hypothesis that glycolytic enzymes might differ between lines. This possibility was confirmed by 2-dimensional electrophoresis for aldolase and phosphoglycerate kinase 1. This outcome warranted evaluation of the whole cell proteome by differential detergent fractionation and mass spectrometry. Bioinformatics evaluation of proteins with different expression levels confirmed the likelihood that ATP metabolism and glycolysis differ between lines. This experimental outcome corroborated differences observed between lines in previous work, which include mitochondrial ultrastructure, sperm cell oxygen consumption, and straight line velocity. Although glycolytic proteins were more abundant within highly mobile sperm, quantitative PCR of representative testis RNA, which included mRNA for phosphoglycerate kinase 1, found no difference between lines. In summary, we propose a proteome-based model for sperm mobility phenotype in which a genetic predisposition puts sperm cells at risk of premature mitochondrial failure as they pass through the excurrent ducts of the testis. In other words, we attribute mitochondrial failure to sperm cell and reproductive tract attributes that interact to affect sperm in a stochastic manner before ejaculation. In conclusion, our work provides a starting point for understanding chicken semen quality in terms of gene networks.
Subject(s)
Chickens/physiology , Fertility/physiology , Mitochondria/physiology , Sperm Motility/physiology , Spermatozoa/physiology , Aniline Compounds/chemistry , Animals , Electrophoresis, Gel, Two-Dimensional/veterinary , Flow Cytometry/veterinary , Fluorescent Dyes/chemistry , Fructose-Bisphosphate Aldolase/genetics , Fructose-Bisphosphate Aldolase/physiology , Male , Mass Spectrometry/veterinary , Mitochondria/ultrastructure , Phenotype , Phosphoglycerate Kinase/genetics , Phosphoglycerate Kinase/physiology , Proteomics/methods , RNA/chemistry , RNA/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sperm Motility/genetics , Spermatozoa/enzymology , Spermatozoa/ultrastructure , Xanthenes/chemistryABSTRACT
As the ultimate electron acceptor in oxidative phosphorylation, oxygen plays a critical role in metabolism. When oxygen levels drop, heterodimeric hypoxia-inducible factor (Hif) transcription factors become active and facilitate adaptation to hypoxia. Hif regulation by oxygen requires the protein von Hippel-Lindau (pVhl) and pVhl disruption results in constitutive Hif activation. The liver is a critical organ for metabolic homeostasis, and Vhl inactivation in hepatocytes results in a Hif-dependent shortening in life span. While albumin-Cre;Vhl(F/F) mice develop hepatic steatosis and impaired fatty acid oxidation, the variable penetrance and unpredictable life expectancy has made the cause of death elusive. Using a system in which Vhl is acutely disrupted and a combination of ex vivo liver perfusion studies and in vivo oxygen measurements, we demonstrate that Vhl is essential for mitochondrial respiration in vivo. Adenovirus-Cre mediated acute Vhl disruption in the liver caused death within days. Deprived of pVhl, livers accumulated tryglicerides and circulating ketone and glucose levels dropped. The phenotype was reminiscent of inborn defects in fatty acid oxidation and of fasted PPARα-deficient mice and while death was unaffected by pharmacologic PPARα activation, it was delayed by glucose administration. Ex vivo liver perfusion analyses and acylcarnitine profiles showed mitochondrial impairment and a profound inhibition of liver ketone and glucose production. By contrast, other mitochondrial functions, such as ureagenesis, were unaffected. Oxygen consumption studies revealed a marked suppression of mitochondrial respiration, which, as determined by magnetic resonance oximetry in live mice, was accompanied by a corresponding increase in liver pO(2). Importantly, simultaneous inactivation of Hif-1ß suppressed liver steatosis and rescued the mice from death. These data demonstrate that constitutive Hif activation in mice is sufficient to suppress mitochondrial respiration in vivo and that no other pathway exists in the liver that can allow oxygen utilization when Hif is active precluding thereby metabolic collapse.
Subject(s)
Hypoglycemia/pathology , Hypoxia/metabolism , Ketones/blood , Liver/metabolism , Oxygen/metabolism , Signal Transduction , Animals , Gluconeogenesis , Hypoglycemia/metabolism , Mice , Reverse Transcriptase Polymerase Chain Reaction , Von Hippel-Lindau Tumor Suppressor Protein/genetics , Von Hippel-Lindau Tumor Suppressor Protein/physiologyABSTRACT
T cells from the spleens of B(19)/B(19) and B(21)/B(21) chickens infected with MDV JM-16 strain were fractionated by flow cytometry at 4, 10, 21 days post infection (d.p.i.). The expression of cytokine and viral genes (meq and glycoprotein B (gB)) was measured by real-time RT-PCR. It was determined that CD4(+) and CD8(+) T cells had both become infected with Marek's disease virus (MDV) in both chicken lines. There was significantly higher expression of meq in CD4(+) T cells compared to CD8(+) T cells at 10 and 21 d.p.i. Furthermore, at 10 and 21 d.p.i., there was a tendency for higher expression of meq in both T cell subsets of B(19) chickens compared to those of B(21) chickens. There were temporal changes in the expression of cytokines, interferon (IFN)-gamma, interleukin (IL)-18, IL-6, and IL-10, in various T cell subsets. Among these changes, there was an increase in IL-10 expression in both T cell subsets at different time points, especially in the susceptible line at 10 and 21 d.p.i. Our results indicate that cytokines could be differentially induced by MDV in CD4(+) and CD8(+) T cell subsets and that IL-10 may play a role in the modulation of immune response to MDV. However, an association between cytokine gene expression in T cell subsets and resistance or susceptibility to MD was not established.