Coronavirus Infections: Virus diseases caused by the CORONAVIRUS genus. Some specifics include transmissible enteritis of turkeys (ENTERITIS, TRANSMISSIBLE, OF TURKEYS); FELINE INFECTIOUS PERITONITIS; and transmissible gastroenteritis of swine (GASTROENTERITIS, TRANSMISSIBLE, OF SWINE).Coronavirus: A genus of the family CORONAVIRIDAE which causes respiratory or gastrointestinal disease in a variety of vertebrates.SARS Virus: A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.Coronaviridae Infections: Virus diseases caused by CORONAVIRIDAE.Severe Acute Respiratory Syndrome: A viral disorder characterized by high FEVER, dry COUGH, shortness of breath (DYSPNEA) or breathing difficulties, and atypical PNEUMONIA. A virus in the genus CORONAVIRUS is the suspected agent.Coronavirus 229E, Human: A species in the genus CORONAVIRUS causing the common cold and possibly nervous system infections in humans. It lacks hemagglutinin-esterase.Coronavirus OC43, Human: A species in the genus CORONAVIRUS causing the common cold and possibly nervous system infections in humans. It contains hemagglutinin-esterase.Coronavirus, Bovine: A species of CORONAVIRUS infecting neonatal calves, presenting as acute diarrhea, and frequently leading to death.Murine hepatitis virus: A species of the CORONAVIRUS genus causing hepatitis in mice. Four strains have been identified as MHV 1, MHV 2, MHV 3, and MHV 4 (also known as MHV-JHM, which is neurotropic and causes disseminated encephalomyelitis with demyelination as well as focal liver necrosis).Coronavirus, Feline: A species of CORONAVIRUS infecting cats of all ages and commonly found in catteries and zoos. Cats are often found carrying the virus but only a small proportion develop disease. Feline coronavirus and Feline infectious peritonitis virus (FIPV) are virtually the same virus in genetic and antigenetic terms, and are morphologically indistinguishable. Since they only differ in their disease potential (with FIPV causing a more serious illness), they are considered biotypes of each other.Spike Glycoprotein, Coronavirus: A class I viral fusion protein that forms the characteristic spikes, or peplomers, found on the viral surface that mediate virus attachment, fusion, and entry into the host cell. During virus maturation, it is cleaved into two subunits: S1, which binds to receptors in the host cell, and S2, which mediates membrane fusion.Coronaviridae: Spherical RNA viruses, in the order NIDOVIRALES, infecting a wide range of animals including humans. Transmission is by fecal-oral and respiratory routes. Mechanical transmission is also common. There are two genera: CORONAVIRUS and TOROVIRUS.Coronavirus, Rat: A species of CORONAVIRUS causing pneumonia in newborn rats but a clinically inapparent infection in adults. It is separate but antigenically related to MURINE HEPATITIS VIRUS.Coronavirus, Canine: A species of CORONAVIRUS infecting dogs. Onset of symptoms is usually sudden and includes vomiting, diarrhea, and dehydration.Transmissible gastroenteritis virus: A species of CORONAVIRUS causing a fatal disease to pigs under 3 weeks old.Feline Infectious Peritonitis: Common coronavirus infection of cats caused by the feline infectious peritonitis virus (CORONAVIRUS, FELINE). The disease is characterized by a long incubation period, fever, depression, loss of appetite, wasting, and progressive abdominal enlargement. Infection of cells of the monocyte-macrophage lineage appears to be essential in FIP pathogenesis.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Infectious bronchitis virus: A species of CORONAVIRUS causing infections in chickens and possibly pheasants. Chicks up to four weeks old are the most severely affected.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Coronavirus NL63, Human: A species in the genus CORONAVIRUS causing upper and lower RESPIRATORY TRACT INFECTIONS. It shares the receptor used by the SARS VIRUS.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).Nucleocapsid Proteins: Viral proteins found in either the NUCLEOCAPSID or the viral core (VIRAL CORE PROTEINS).Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Cytopathogenic Effect, Viral: Visible morphologic changes in cells infected with viruses. It includes shutdown of cellular RNA and protein synthesis, cell fusion, release of lysosomal enzymes, changes in cell membrane permeability, diffuse changes in intracellular structures, presence of viral inclusion bodies, and chromosomal aberrations. It excludes malignant transformation, which is CELL TRANSFORMATION, VIRAL. Viral cytopathogenic effects provide a valuable method for identifying and classifying the infecting viruses.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Peptidyl-Dipeptidase A: A peptidyl-dipeptidase that catalyzes the release of a C-terminal dipeptide, -Xaa-*-Xbb-Xcc, when neither Xaa nor Xbb is Pro. It is a Cl(-)-dependent, zinc glycoprotein that is generally membrane-bound and active at neutral pH. It may also have endopeptidase activity on some substrates. (From Enzyme Nomenclature, 1992) EC 18.104.22.168.Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Coronavirus, Turkey: A species of CORONAVIRUS causing enteritis in turkeys and pullets.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Porcine Respiratory Coronavirus: A mutant strain of TRANSMISSIBLE GASTROENTERITIS VIRUS causing mild or subclinical respiratory infections in young SWINE. It may also play a role in post-weaning porcine respiratory disease complex, especially when combined with other respiratory agents.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Gastroenteritis, Transmissible, of Swine: A condition of chronic gastroenteritis in adult pigs and fatal gastroenteritis in piglets caused by a CORONAVIRUS.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Viral Proteins: Proteins found in any species of virus.Viverridae: The family of civets which are small and medium-sized Old World carnivores, often striped or spotted.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.RNA Replicase: An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Enteritis, Transmissible, of Turkeys: An acute, highly contagious virus disease of turkeys characterized by chilling, anorexia, decreased water intake, diarrhea, dehydration and weight loss. The infectious agent is a CORONAVIRUS.Viral Matrix Proteins: Proteins associated with the inner surface of the lipid bilayer of the viral envelope. These proteins have been implicated in control of viral transcription and may possibly serve as the "glue" that binds the nucleocapsid to the appropriate membrane site during viral budding from the host cell.Viral Nonstructural Proteins: Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.Antigens, CD13: Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.Nucleocapsid: A protein-nucleic acid complex which forms part or all of a virion. It consists of a CAPSID plus enclosed nucleic acid. Depending on the virus, the nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope.