|
Avian Bornavirus (ABV)
In 2008, by pyrosequencing of cDNA from the brains of several parrots suffering from proventricular dilatation disease (PDD), Honkavuori et al. identified the presence of a novel bornavirus. Discovery Using real time PCR, the investigators confirmed the presence of this virus in the brains and proventriculus of three cases of PDD but not in four unaffected birds. At approximately the same time, Kistler and her colleagues used a microarray approach to identify a bornavirus hybridization signature in three out of five PDD cases but not in eight control parrots. Recovery and naming Using high-throughput pyrosequencing in combination with conventional PCR cloning and sequencing, these investigators recovered the complete viral genome sequence and named this virus "avian bornavirus". Today, several distinct avian bornaviruses are distinguished. In general these viruses show only about 65% sequence identity with mammalian Borna disease virus 1 (BoDV-1). Taxonomy Structure The over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proventricular Dilatation Disease
Proventricular dilatation disease (PDD) is an incurable probably viral disease of psittacine birds. It was first recognized and described in 1978 by Dr. Hannis L. Stoddard. Since the first reported cases were involving species of macaw, the condition was termed macaw wasting syndrome. Clinical signs The clinical presentation of this disease varies with the individual as well as in severity of those symptoms. Often the symptoms include a gastrointestinal component, but many times birds with this disease will present with neurologic signs as well, or in lieu of digestive anomalies. Gastrointestinal signs may include: Regurgitation, crop impaction, poor appetite, weight loss, or passage of undigested food in the feces.Harrison, and Lightfoot. 2006 ''Clinical Avian Medicine''. Spix Publishing, Palm Beach, Florida. Neurologic symptoms may include: Weakness, ataxia, paresis, proprioceptive deficits, head tremors, and rarely seizures. Muscle wasting and a generalized poor body condition i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bornavirus
''Bornaviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Horses, sheep, cattle, rodents, birds, reptiles, and humans serve as natural hosts. Diseases associated with bornaviruses include Borna disease, a fatal neurologic disease of mammals restricted to central Europe; and Proventricular dilatation disease, proventricular dilatation disease (PDD) in birds. Bornaviruses may cause encephalitis in mammals like horses or sheep. The family contains four genera. History Borna disease was first identified in 1926 and its genome was isolated in 1990. The ICTV proposed the creation in 1996 of the family ''Bornaviridae'' along with the genus ''Bornaviru''s (today ''Orthobornavirus''). The viral family is named after the city of Borna, Leipzig, Borna in Saxony, Saxony, Germany, which is where many animals were lost to the sporadic encephalopathy caused by the viral disease. Structure Orthobornavirions are enveloped, with spherical geometries and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation. Mullis and biochemist Michael Smith (chemist), Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993. PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of Ancient DNA, ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proventriculus
The proventriculus is part of the digestive system of birds.Encarta World English Dictionary orth American Edition(2007). ''Proventriculus''. Source: (accessed: December 18, 2007) An analogous organ exists in invertebrates and insects. Birds The proventriculus is a standard part of avian anatomy and is a rod-shaped organ, located between the esophagus and the gizzard of most birds. It is generally a glandular part of the stomach that may store and/or commence the digestion of food before it progresses to the gizzard. The primary function of the proventriculus is to secrete hydrochloric acid (HCl) and digestive enzymes such as pepsinogen into the digestive compartments that will churn the ingested material through muscular mechanisms. Thomas Cecere (College of Veterinary Medicine of Virginia Tech) says of the proventriculus: The proventriculus is the glandular portion of the avian compound stomach, and a rather peculiar organ it is. There's nothing like it in mammals. Sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microarray
A microarray is a multiplex (assay), multiplex lab-on-a-chip. Its purpose is to simultaneously detect the expression of thousands of biological interactions. It is a two-dimensional array on a Substrate (materials science), solid substrate—usually a glass slide or silicon thin-film cell—that assays (tests) large amounts of biotic material, biological material using high-throughput screening miniaturized, multiplexed and parallel processing and detection methods. The concept and methodology of microarrays was first introduced and illustrated in antibody microarrays (also referred to as antibody matrix) by Tse Wen Chang in 1983 in a scientific publication and a series of patents. The "gene chip" industry started to grow significantly after the 1995 ''Science Magazine'' article by the Ron Davis and Pat Brown labs at Stanford University. With the establishment of companies, such as Affymetrix, Agilent, Applied Microarrays, Arrayjet, Illumina (company), Illumina, and others, the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloning
Cloning is the process of producing individual organisms with identical genomes, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction; this reproduction of an organism by itself without a mate is known as parthenogenesis. In the field of biotechnology, cloning is the process of creating cloned organisms of Cell (biology), cells and of DNA fragments. The artificial cloning of organisms, sometimes known as reproductive cloning, is often accomplished via somatic-cell nuclear transfer (SCNT), a cloning method in which a viable embryo is created from a somatic cell and an egg cell. In 1996, Dolly (sheep), Dolly the sheep achieved notoriety for being the first mammal cloned from a somatic cell. Another example of artificial cloning is molecular cloning, a technique in molecular biology in which a single living cell is used to clone a large population of cells that contain identical DNA molecules. In bioethics, there are a vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome Sequence
A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of junk DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The first genome to be sequenced was that of the virus φX174 in 1977; the first genome sequence of a prokaryote (''Haemophilus influenzae'') was published in 1995; the yeast (''Saccharomyces cerevisiae'') genome was the first eukaryotic genome to be sequenced in 1996. The Human Genome Project was started in October 1990, and the first draft sequences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bornaviridae
''Bornaviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Horses, sheep, cattle, rodents, birds, reptiles, and humans serve as natural hosts. Diseases associated with bornaviruses include Borna disease, a fatal neurologic disease of mammals restricted to central Europe; and Proventricular dilatation disease, proventricular dilatation disease (PDD) in birds. Bornaviruses may cause encephalitis in mammals like horses or sheep. The family contains four genera. History Borna disease was first identified in 1926 and its genome was isolated in 1990. The ICTV proposed the creation in 1996 of the family ''Bornaviridae'' along with the genus ''Bornaviru''s (today ''Orthobornavirus''). The viral family is named after the city of Borna, Leipzig, Borna in Saxony, Saxony, Germany, which is where many animals were lost to the sporadic encephalopathy caused by the viral disease. Structure Orthobornavirions are enveloped, with spherical geometries and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Committee On Taxonomy Of Viruses
The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclature for viruses. The ICTV develops a universal taxonomic scheme for viruses, and thus has the means to appropriately describe, name, and classify every virus taxon. The members of the International Committee on Taxonomy of Viruses are considered expert virologists. The ICTV was formed from and is governed by the Virology Division of the International Union of Microbiological Societies. Detailed work, such as identifying new taxa and delimiting the boundaries of species, genera, families, etc. typically is performed by study groups of experts in the families. History The International Committee on Nomenclature of Viruses (ICNV) was established in 1966, at the International Congress for Microbiology in Moscow, to standardize the naming of virus taxa. The ICVN published its first report in 1971. For viruses infecting vertebrates, the first report i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bornavirus
''Bornaviridae'' is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Horses, sheep, cattle, rodents, birds, reptiles, and humans serve as natural hosts. Diseases associated with bornaviruses include Borna disease, a fatal neurologic disease of mammals restricted to central Europe; and Proventricular dilatation disease, proventricular dilatation disease (PDD) in birds. Bornaviruses may cause encephalitis in mammals like horses or sheep. The family contains four genera. History Borna disease was first identified in 1926 and its genome was isolated in 1990. The ICTV proposed the creation in 1996 of the family ''Bornaviridae'' along with the genus ''Bornaviru''s (today ''Orthobornavirus''). The viral family is named after the city of Borna, Leipzig, Borna in Saxony, Saxony, Germany, which is where many animals were lost to the sporadic encephalopathy caused by the viral disease. Structure Orthobornavirions are enveloped, with spherical geometries and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA for the purpose of gene expression. Some segments of DNA are transcribed into RNA molecules that can encode proteins, called messenger RNA (mRNA). Other segments of DNA are transcribed into RNA molecules called non-coding RNAs (ncRNAs). Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. In virology, the term transcription is used when referring to mRNA synthesis from a viral RNA molecule. The genome of many RNA viruses is composed of negative-sense RNA which acts as a template for positive sense viral messenger RNA - a necessary step in the synthesis of viral proteins needed for viral replication. This process is catalyzed by a viral RNA dependent RNA polymerase. Background A DNA transcription unit encoding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
