A group of transmissible viral diseases of chickens and turkeys. Liver tumors are found in most forms, but tumors can be found elsewhere.
The type species of ALPHARETROVIRUS producing latent or manifest lymphoid leukosis in fowl.
A genus of the family RETROVIRIDAE with type C morphology, that causes malignant and other diseases in wild birds and domestic fowl.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
An epithelial outgrowth of the cloaca in birds similar to the thymus in mammals. It atrophies within 6 months after birth and remains as a fibrous remnant in adult birds. It is composed of lymphoid tissue and prior to involution, is the site of B-lymphocyte maturation.
Proteins obtained from species of BIRDS.
Group of alpharetroviruses (ALPHARETROVIRUS) producing sarcomata and other tumors in chickens and other fowl and also in pigeons, ducks, and RATS.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
A lymphoid neoplastic disease in cattle caused by the bovine leukemia virus. Enzootic bovine leukosis may take the form of lymphosarcoma, malignant lymphoma, or leukemia but the presence of malignant cells in the blood is not a consistent finding.
Diseases of birds which are raised as a source of meat or eggs for human consumption and are usually found in barnyards, hatcheries, etc. The concept is differentiated from BIRD DISEASES which is for diseases of birds not considered poultry and usually found in zoos, parks, and the wild.
A species in the group RETICULOENDOTHELIOSIS VIRUSES, AVIAN of the genus GAMMARETROVIRUS that causes a chronic neoplastic and a more acute immunosuppressive disease in fowl.
Connective tissue tumors, affecting primarily fowl, that are usually caused by avian sarcoma viruses.
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.
Common name for two distinct groups of BIRDS in the order GALLIFORMES: the New World or American quails of the family Odontophoridae and the Old World quails in the genus COTURNIX, family Phasianidae.
A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.
DNA sequences that form the coding region for retroviral enzymes including reverse transcriptase, protease, and endonuclease/integrase. "pol" is short for polymerase, the enzyme class of reverse transcriptase.
A transmissible viral disease of birds caused by avian herpesvirus 2 (HERPESVIRUS 2, GALLID) and other MARDIVIRUS. There is lymphoid cell infiltration or lymphomatous tumor formation in the peripheral nerves and gonads, but may also involve visceral organs, skin, muscle, and the eye.
Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.
DNA sequences that form the coding region for the viral envelope (env) proteins in retroviruses. The env genes contain a cis-acting RNA target sequence for the rev protein (= GENE PRODUCTS, REV), termed the rev-responsive element (RRE).
A vascular anomaly due to proliferation of BLOOD VESSELS that forms a tumor-like mass. The common types involve CAPILLARIES and VEINS. It can occur anywhere in the body but is most frequently noticed in the SKIN and SUBCUTANEOUS TISSUE. (from Stedman, 27th ed, 2000)
Deoxyribonucleic acid that makes up the genetic material of viruses.
A general term for various neoplastic diseases of the lymphoid tissue.
The type species of the genus MARDIVIRUS in the family HERPESVIRIDAE. It is the etiologic agent of MAREK DISEASE, infecting domestic fowl and wild birds.
Malignant neoplasms composed of MACROPHAGES or DENDRITIC CELLS. Most histiocytic sarcomas present as localized tumor masses without a leukemic phase. Though the biological behavior of these neoplasms resemble lymphomas, their cell lineage is histiocytic not lymphoid.
DNA sequences that form the coding region for proteins associated with the viral core in retroviruses. gag is short for group-specific antigen.
A species of ALPHARETROVIRUS causing anemia in fowl.
Viruses which enable defective viruses to replicate or to form a protein coat by complementing the missing gene function of the defective (satellite) virus. Helper and satellite may be of the same or different genus.
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The functional hereditary units of VIRUSES.
Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.
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.
Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.
Genes whose gain-of-function alterations lead to NEOPLASTIC CELL TRANSFORMATION. They include, for example, genes for activators or stimulators of CELL PROLIFERATION such as growth factors, growth factor receptors, protein kinases, signal transducers, nuclear phosphoproteins, and transcription factors. A prefix of "v-" before oncogene symbols indicates oncogenes captured and transmitted by RETROVIRUSES; the prefix "c-" before the gene symbol of an oncogene indicates it is the cellular homolog (PROTO-ONCOGENES) of a v-oncogene.
Ribonucleic acid that makes up the genetic material of viruses.
Retroviruses that have integrated into the germline (PROVIRUSES) that have lost infectious capability but retained the capability to transpose.
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC
Inflammation of the synovial lining of a tendon sheath. Causes include trauma, tendon stress, bacterial disease (gonorrhea, tuberculosis), rheumatic disease, and gout. Common sites are the hand, wrist, shoulder capsule, hip capsule, hamstring muscles, and Achilles tendon. The tendon sheaths become inflamed and painful, and accumulate fluid. Joint mobility is usually reduced.
Established cell cultures that have the potential to propagate indefinitely.
A phenomenon in which infection by a first virus results in resistance of cells or tissues to infection by a second, unrelated virus.
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.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
The type species of DELTARETROVIRUS that causes a form of bovine lymphosarcoma (ENZOOTIC BOVINE LEUKOSIS) or persistent lymphocytosis.
Insertion of viral DNA into host-cell DNA. This includes integration of phage DNA into bacterial DNA; (LYSOGENY); to form a PROPHAGE or integration of retroviral DNA into cellular DNA to form a PROVIRUS.
An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.
Proteins from the family Retroviridae. The most frequently encountered member of this family is the Rous sarcoma virus protein.
Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.
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.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.
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.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
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.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Substances elaborated by viruses that have antigenic activity.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
The complete genetic complement contained in a DNA or RNA molecule in a virus.

Identification of key residues in subgroup A avian leukosis virus envelope determining receptor binding affinity and infectivity of cells expressing chicken or quail Tva receptor. (1/162)

To better understand retroviral entry, we have characterized the interactions between subgroup A avian leukosis virus [ALV(A)] envelope glycoproteins and Tva, the receptor for ALV(A), that result in receptor interference. We have recently shown that soluble forms of the chicken and quail Tva receptor (sTva), expressed from genes delivered by retroviral vectors, block ALV(A) infection of cultured chicken cells ( approximately 200-fold antiviral effect) and chickens (>98% of the birds were not infected). We hypothesized that inhibition of viral replication by sTva would select virus variants with mutations in the surface glycoprotein (SU) that altered the binding affinity of the subgroup A SU for the sTva protein and/or altered the normal receptor usage of the virus. Virus propagation in the presence of quail sTva-mIgG, the quail Tva extracellular region fused to the constant region of the mouse immunoglobulin G (IgG) protein, identified viruses with three mutations in the subgroup A hr1 region of SU, E149K, Y142N, and Y142N/E149K. These mutations reduced the binding affinity of the subgroup A envelope glycoproteins for quail sTva-mIgG (32-, 324-, and 4,739-fold, respectively) but did not alter their binding affinity for chicken sTva-mIgG. The ALV(A) mutants efficiently infected cells expressing the chicken Tva receptor but were 2-fold (E149K), 10-fold (Y142N), and 600-fold (Y142N/E149K) less efficient at infecting cells expressing the quail Tva receptor. These mutations identify key determinants of the interaction between the ALV(A) glycoproteins and the Tva receptor. We also conclude from these results that, at least for the wild-type and variant ALV(A)s tested, the receptor binding affinity was directly related to infection efficiency.  (+info)

Role of calcium in protein folding and function of Tva, the receptor of subgroup A avian sarcoma and leukosis virus. (2/162)

Tva is the cellular receptor for subgroup A avian sarcoma and leukosis virus (ASLV-A). The viral receptor function of Tva is determined by a 40-residue cysteine-rich motif called the LDL-A module. In this study, we expressed and purified the wild-type (wt) Tva LDL-A module as well as several mutants and examined their in vitro folding properties. We found that, as for other LDL-A modules, correct folding and structure of the Tva LDL-A module is Ca2+ dependent. When calcium was present during in vitro protein folding, the wt module was eluted as a single peak by reverse-phase high-pressure liquid chromatography. Furthermore, two-dimensional nuclear magnetic resonance (NMR) spectroscopy gave well-dispersed spectra in the presence of calcium. In contrast, the same protein folded in vitro in the absence of calcium was eluted as multiple broad peaks and gave a poorly dispersed NMR spectrum in the presence of calcium. The calcium affinity (Kd) of the Tva LDL-A module, determined by isothermal titration calorimetry, is approximately 40 microM. Characterization of several Tva mutants provided further evidence that calcium is important in protein folding and function of Tva. Mutations of the Ca2+-binding residues (D46A and E47A) completely abrogated the Ca2+-binding ability of Tva, and the proteins were not correctly folded. Interestingly, mutations of two non-calcium-binding residues (W48A and L34A) also exerted adverse effect on Ca2+-dependent folding, albeit to a much less extent. Our results provide new insights regarding the structure and function of Tva in ASLV-A entry.  (+info)

Isolation and characterization of nuclear RNA polymerase II from chicken myeloblastosis cells. (3/162)

Nuclear RNA polymerases of chicken myeloblastosis cells were solubilized and fractionated by diethylaminoethyl-Sephades A25 column chromatography. Both alpha-amanitin-insenstitive (polymerase I) and- sensitive (polymerase II) species were isolated. Polymerase activity, contained two peaks of enzyme (IIa and IIb), which were further purified by glycerol gradient centrifugation. The partially purified enzymes were characterized by their requirement of four nucleoside triphosphates and metal ions and by their sensitivity to several inhibitors. The enzymes were compared with RNA polymearases derived from normal chickent bone marrow cells,and the total extractable myeloblastosis than in bone marrow cells. Polymearse II from both cell types was shown to be sensitive to cytosine arabinoside triphosphate inhibiton.  (+info)

Avian erythroleukemia: a model for corepressor function in cancer. (4/162)

Transcriptional regulation at the level of chromatin plays crucial roles during eukaryotic development and differentiation. A plethora of studies revealed that the acetylation status of histones is controlled by multi-protein complexes containing (de)acetylase activities. In the current model, histone deacetylases and acetyltransferases are recruited to chromatin by DNA-bound repressors and activators, respectively. Shifting the balance between deacetylation, i.e. repressive chromatin and acetylation, i.e. active chromatin can lead to aberrant gene transcription and cancer. In human acute promyelocytic leukemia (APL) and avian erythroleukemia (AEL), chromosomal translocations and/or mutations in nuclear hormone receptors, RARalpha [NR1B1] and TRalpha [NR1A1], yielded oncoproteins that deregulate transcription and alter chromatin structure. The oncogenic receptors are locked in their 'off' mode thereby constitutively repressing transcription of genes that are critical for differentiation of hematopoietic cells. AEL involves an oncogenic version of the chicken TRalpha, v-ErbA. Apart from repression by v-ErbA via recruitment of corepressor complexes, other repressors and corepressors appear to be involved in repression of v-ErbA target genes, such as carbonic anhydrase II (CAII). Reactivation of repressed genes in APL and AEL by chromatin modifying agents such as inhibitors of histone deacetylase or of methylation provides new therapeutic strategies in the treatment of acute myeloid leukemia.  (+info)

Heterophil function and resistance to staphylococcal challenge in broiler chickens naturally infected with avian leukosis virus subgroup J. (5/162)

Avian leukosis virus subgroup J has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. The impact of congenital avian leukosis virus subgroup J infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. Six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup J were inoculated intravenously with 10(6) colony-forming units of Staphylococcus aureus, and pre- and postinoculation heterophil function was assessed. All chickens developed a leukocytosis with heterophilia after inoculation, but total leukocyte and heterophil counts were significantly higher in leukosis-negative chickens than in virus-infected chickens. Tenosynovitis was more severe in leukosis-negative chickens, and 2/10 (20%) of the virus-infected chickens had no histologic evidence of tenosynovitis. Osteomyelitis in the tibiotarsus or tarsometatarsus developed in 5/10 (50%) of the chickens in each group. S. aureus was recovered from the hock joint of 6/10 (60%) of the chickens in each group. Heterophils from all chickens exhibited similar phagocytic ability pre- and postinoculation. Heterophils from virus-infected chickens exhibited less bactericidal ability preinoculation than did heterophils from leukosis-negative chickens. However, postinoculation bactericidal ability was similar in both groups. Avian leukosis virus subgroup J provirus was present in heterophils isolated from congenitally infected chickens. Heterophils isolated from broiler chickens congenitally infected with avian leukosis virus subgroup J exhibit no significant functional deficits, and infected and uninfected chickens exhibit similar susceptibility to staphylococcal infection.  (+info)

Localization of avian leukosis virus subgroup J in naturally infected chickens by RNA in situ hybridization. (6/162)

The novel subgroup J of avian leukosis virus (ALV-J) has emerged as a significant cause of myeloid neoplasia and weight suppression in broiler chickens. We investigated viral tropism using RNA in situ hybridization (ISH) in naturally infected chickens. Formalin-fixed tissues were collected from 12-day-old embryos (seven infected, two control) and from 0-week-old (four infected, one control), 3-week-old (five infected, one control), 6-week-old (five infected, one control), and 9-week-old (10 infected, two control) chickens naturally infected with ALV-J in ovo. A 636-base antisense riboprobe complementary to the 3' and 5' ends of the pol and env viral genes, respectively, was constructed. Strong positive staining was present in cardiac myocytes, Purkinje fibers, vascular and pulmonary smooth muscle, renal glomeruli, distal tubules, and pituitary glands. Light staining was present in gastrointestinal smooth muscle, thyroid and adrenal glands, and follicular medullae in the cloacal bursa. Staining was not present in any hematopoietic precursors. Tissues from newly hatched chicks exhibited the strongest and most consistent staining, whereas staining in embryos was minimal. RNA ISH confirmed the presence of ALV-J-specific nucleic acid within cytoplasmic inclusions in cardiac myocytes, Purkinje fibers, pituitary glands, and renal glomeruli. Viral tropism for cardiac myocytes and Purkinje fibers may relate pathogenetically to the cardiomyopathy and congestive heart failure described in index chicken flocks infected with ALV-J. Viral tropism for endocrine organs may relate pathogenetically to the weight suppression associated with infection.  (+info)

Avian bic, a gene isolated from a common retroviral site in avian leukosis virus-induced lymphomas that encodes a noncoding RNA, cooperates with c-myc in lymphomagenesis and erythroleukemogenesis. (7/162)

bic is a novel gene identified at a common retroviral integration site in avian leukosis virus-induced lymphomas and has been implicated as a collaborator with c-myc in B lymphomagenesis. It lacks an extensive open reading frame and is believed to function as an untranslated RNA (W. Tam, Gene 274:157-167, 2001; W. Tam, D. Ben-Yehuda, and W. S. Hayward, Mol. Cell. Biol. 17:1490-1502, 1997). The oncogenic potential of bic, particularly its ability to cooperate with c-myc in oncogenesis, was tested directly by expressing c-myc and bic, either singly or in pairwise combination, in cultured chicken embryo fibroblasts (CEFs) and in chickens using replication-competent retrovirus vectors. Coexpression of c-myc and bic in CEFs caused growth enhancement of cells. Most importantly, chick oncogenicity assays demonstrated that bic can cooperate with c-myc in lymphomagenesis and erythroleukemogenesis. The present study provides direct evidence for the involvement of untranslated RNAs in oncogenesis and provides further support for the role of noncoding RNAs as riboregulators.  (+info)

Cardiomyopathy in broiler chickens congenitally infected with avian leukosis virus subgroup J. (8/162)

Dilated cardiomyopathy and ascites in broiler chickens are frequently associated with rapid growth and pulmonary hypertension, but can be associated with some avian leukosis virus (ALV) infections. The novel subgroup J of ALV has a high cardiac tropism, but dilated cardiomyopathy has not been reported previously. We report a dilated cardiomyopathy incidence of 11.1% in broiler chickens congenitally infected with ALV subgroup J (ALV-J). Gross lesions included severe body weight suppression, cardiomegaly with biventricular dilation, right ventricular hypertrophy, visceral congestion, and ascites. Cardiac myocytes and Purkinje fibers contained 2- to 10-microm intracytoplasmic magenta inclusions that contained ALV-J-specific nucleic acid. Ultrastructurally, inclusions contained ribosomes and immature virions and were associated with myofibril disruption and disarray. Peracute centrilobular hepatic necrosis was present in most cases. ALV-J-associated cardiomyopathy may involve a direct viral effect on cardiac myocytes and Purkinje fibers.  (+info)

Avian leukosis is a group of viral diseases that primarily affect chickens and other birds. It is caused by retroviruses known as avian leukosis viruses (ALVs) and leads to a variety of clinical signs, including immunosuppression, growth retardation, and the development of tumors in various organs. The disease can be transmitted both horizontally (through direct contact with infected birds or their secretions) and vertically (from infected hens to their offspring through the egg).

There are several subgroups of ALVs, each associated with specific types of tumors and clinical manifestations. For example:

1. ALV-J (Japanese strain): This subgroup is responsible for myelocytomatosis, a condition characterized by the proliferation of immature blood cells in the bone marrow, leading to anemia, leukopenia, and enlarged spleens and livers.
2. ALV-A, ALV-B, and ALV-C (American strains): These subgroups are associated with various types of lymphoid tumors, such as B-cell and T-cell lymphomas, which can affect the bursa of Fabricius, thymus, spleen, and other organs.
3. ALV-E (European strain): This subgroup is linked to erythroblastosis, a condition in which there is an excessive proliferation of red blood cell precursors, resulting in the formation of tumors in the bone marrow and other organs.

Avian leukosis poses significant economic challenges for the poultry industry due to its impact on growth, feed conversion efficiency, and mortality rates. Additionally, some countries have regulations in place to prevent the spread of avian leukosis viruses through the trade of infected birds or their products. Prevention measures include strict biosecurity protocols, vaccination programs, and rigorous screening and eradication strategies for infected flocks.

Avian leukosis virus (ALV) is a type of retrovirus that primarily affects chickens and other birds. It is responsible for a group of diseases known as avian leukosis, which includes various types of tumors and immunosuppressive conditions. The virus is transmitted horizontally through the shedder's dander, feathers, and vertical transmission through infected eggs.

There are several subgroups of ALV (A, B, C, D, E, and J), each with different host ranges and pathogenicity. Some strains can cause rapid death in young chickens, while others may take years to develop clinical signs. The most common form of the disease is neoplastic, characterized by the development of various types of tumors such as lymphomas, myelomas, and sarcomas.

Avian leukosis virus infection can have significant economic impacts on the poultry industry due to decreased growth rates, increased mortality, and condemnation of infected birds at processing. Control measures include eradication programs, biosecurity practices, vaccination, and breeding for genetic resistance.

An alpharetrovirus is a type of retrovirus, which is a group of viruses that integrate their genetic material into the DNA of the host cell. Alpharetroviruses are characterized by their ability to cause persistent infections and are associated with various diseases in animals. One well-known example of an alpharetrovirus is the Rous sarcoma virus (RSV), which was the first retrovirus to be discovered and is known to cause cancer in chickens.

Alpharetroviruses have a complex structure, consisting of an outer envelope that contains glycoprotein spikes, and an inner core that contains the viral RNA genome and associated enzymes. The viral RNA genome contains three main genes: gag, pol, and env, which encode for the structural proteins, enzymes, and envelope proteins of the virus, respectively.

Alpharetroviruses are transmitted through various routes, including horizontal transmission (from host to host) and vertical transmission (from parent to offspring). They can cause a range of diseases, depending on the specific virus and the host species. In addition to RSV, other examples of alpharetroviruses include the avian leukosis virus, which causes tumors and immunosuppression in birds, and the Jaagsiekte sheep retrovirus, which causes a wasting disease in sheep.

It's worth noting that while alpharetroviruses are associated with diseases in animals, there are no known alpharetroviruses that infect humans. However, understanding the biology and behavior of these viruses in animal hosts can provide valuable insights into retroviral replication and pathogenesis, which may have implications for human health.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

The Bursa of Fabricius is a lymphoid organ located in the cloaca of birds. It plays a crucial role in the development of the bird's immune system, specifically in the maturation and differentiation of B cells, which are a type of white blood cell responsible for producing antibodies to fight off infections.

The Bursa of Fabricius is named after the Italian anatomist Hieronymus Fabricius (1537-1619), who first described it in 1621. It is a sac-like structure that is lined with epithelial cells and contains lymphoid follicles, which are clusters of B cells at various stages of development.

In chickens, the Bursa of Fabricius begins to develop around the 5th day of incubation and reaches its maximum size by the time the bird is about 3 weeks old. After this point, it gradually involutes and disappears by the time the bird reaches adulthood.

It's worth noting that the Bursa of Fabricius has no direct equivalent in mammals, including humans. While mammals also have lymphoid organs such as the spleen, lymph nodes, and tonsils, these organs serve different functions and are not directly involved in the maturation of B cells.

I'm not aware of a specific medical definition for "Avian Proteins." The term "avian" generally refers to birds or their characteristics. Therefore, "avian proteins" would likely refer to proteins that are found in birds or are produced by avian cells. These proteins could have various functions and roles, depending on the specific protein in question.

For example, avian proteins might be of interest in medical research if they have similarities to human proteins and can be used as models to study protein function, structure, or interaction with other molecules. Additionally, some avian proteins may have potential applications in therapeutic development, such as using chicken egg-derived proteins for wound healing or as vaccine components.

However, without a specific context or reference, it's difficult to provide a more precise definition of "avian proteins" in a medical context.

Avian sarcoma viruses (ASVs) are a group of retroviruses that primarily infect birds and cause various types of tumors, particularly sarcomas. These viruses contain an oncogene, which is a gene that has the ability to transform normal cells into cancerous ones. The oncogene in ASVs is often derived from cellular genes called proto-oncogenes, which are normally involved in regulating cell growth and division.

ASVs can be divided into two main types: non-defective and defective. Non-defective ASVs contain a complete set of viral genes that allow them to replicate independently, while defective ASVs lack some of the necessary viral genes and require assistance from other viruses to replicate.

One well-known example of an avian sarcoma virus is the Rous sarcoma virus (RSV), which was first discovered in chickens by Peyton Rous in 1910. RSV causes a highly malignant form of sarcoma in chickens and has been extensively studied as a model system for cancer research. The oncogene in RSV is called v-src, which is derived from the normal cellular gene c-src.

Avian sarcoma viruses have contributed significantly to our understanding of the molecular mechanisms underlying cancer development and have provided valuable insights into the role of oncogenes in tumorigenesis.

A chick embryo refers to the developing organism that arises from a fertilized chicken egg. It is often used as a model system in biological research, particularly during the stages of development when many of its organs and systems are forming and can be easily observed and manipulated. The study of chick embryos has contributed significantly to our understanding of various aspects of developmental biology, including gastrulation, neurulation, organogenesis, and pattern formation. Researchers may use various techniques to observe and manipulate the chick embryo, such as surgical alterations, cell labeling, and exposure to drugs or other agents.

Enzootic bovine leukosis (EBL) is a slow-developing, persistent virus infection that primarily affects cattle. It is caused by the bovine leukemia virus (BLV), which is part of the retrovirus family. The term "enzootic" refers to an animal disease that is constantly present in a particular geographic area or population.

EBL is typically characterized by the development of malignant lymphosarcoma, a type of cancer affecting the lymphoid system, in mature animals. Infected animals may not show any clinical signs for several years, and some never develop the disease. However, when clinical symptoms do appear, they can include weight loss, decreased milk production, enlarged lymph nodes, difficulty swallowing, and paralysis.

The virus is primarily spread through contact with infected blood or other bodily fluids, such as during castration, dehorning, or veterinary procedures. It can also be transmitted from an infected mother to her calf through colostrum and milk. EBL has been reported in many countries worldwide, but control and eradication programs have significantly reduced its prevalence in some regions, including the United States and Western Europe.

It is important to note that enzootic bovine leukosis should not be confused with bovine spongiform encephalopathy (BSE), also known as "mad cow disease," which is a completely different and unrelated condition affecting cattle.

Poultry diseases refer to a wide range of infectious and non-infectious disorders that affect domesticated birds, particularly those raised for meat, egg, or feather production. These diseases can be caused by various factors including viruses, bacteria, fungi, parasites, genetic predisposition, environmental conditions, and management practices.

Infectious poultry diseases are often highly contagious and can lead to significant economic losses in the poultry industry due to decreased production, increased mortality, and reduced quality of products. Some examples of infectious poultry diseases include avian influenza, Newcastle disease, salmonellosis, colibacillosis, mycoplasmosis, aspergillosis, and coccidiosis.

Non-infectious poultry diseases can be caused by factors such as poor nutrition, environmental stressors, and management issues. Examples of non-infectious poultry diseases include ascites, fatty liver syndrome, sudden death syndrome, and various nutritional deficiencies.

Prevention and control of poultry diseases typically involve a combination of biosecurity measures, vaccination programs, proper nutrition, good management practices, and monitoring for early detection and intervention. Rapid and accurate diagnosis of poultry diseases is crucial to implementing effective treatment and prevention strategies, and can help minimize the impact of disease outbreaks on both individual flocks and the broader poultry industry.

Reticuloendotheliosis virus (REV) is not a single virus but a group of related viruses that can cause a variety of diseases in birds, including reticuloendotheliosis, lymphomas, and immunosuppression. These viruses belong to the family Retroviridae and the genus Gammaretrovirus. They have been identified in several bird species, including chickens, turkeys, quails, and pheasants.

Reticuloendotheliosis virus can cause a range of clinical signs, depending on the age and immune status of the infected bird. The virus primarily targets the reticuloendothelial system, which includes cells such as macrophages, lymphocytes, and endothelial cells. Infection with REV can lead to the development of tumors in various organs, including the liver, spleen, and bone marrow.

The virus is transmitted horizontally through direct contact with infected birds or their feces, as well as vertically from infected parents to their offspring. Control measures for reticuloendotheliosis include biosecurity practices, vaccination, and testing and culling of infected birds.

I'm sorry for any confusion, but "Avian Sarcoma" is not a widely recognized medical term. The term "sarcoma" is used in pathology to describe a type of cancer that develops from certain types of connective tissue (such as bone, cartilage, muscle, or blood vessels).

On the other hand, "avian" refers to birds or related to birds. In medical literature, avian sarcomas are sometimes used to describe sarcomas that occur in birds. However, specific types of avian sarcomas would be defined by the type of cell from which they originate (like a fibrosarcoma, osteosarcoma, etc.).

If you're asking about a specific medical condition or context, could you please provide more details? I'm here to help!

Virus receptors are specific molecules (commonly proteins) on the surface of host cells that viruses bind to in order to enter and infect those cells. This interaction between the virus and its receptor is a critical step in the infection process. Different types of viruses have different receptor requirements, and identifying these receptors can provide important insights into the biology of the virus and potential targets for antiviral therapies.

I believe there may be some confusion in your question. "Quail" is typically used to refer to a group of small birds that belong to the family Phasianidae and the subfamily Perdicinae. There is no established medical definition for "quail."

However, if you're referring to the verb "to quail," it means to shrink back, draw back, or cower, often due to fear or intimidation. In a medical context, this term could be used metaphorically to describe a patient's psychological response to a threatening situation, such as receiving a difficult diagnosis. But again, "quail" itself is not a medical term.

"Coturnix" is a genus of birds that includes several species of quails. The most common species is the Common Quail (Coturnix coturnix), which is also known as the European Quail or the Eurasian Quail. This small ground-dwelling bird is found throughout Europe, Asia, and parts of Africa, and it is known for its distinctive call and its migratory habits. Other species in the genus Coturnix include the Rain Quail (Coturnix coromandelica), the Stubble Quail (Coturnix pectoralis), and the Harlequin Quail (Coturnix delegorguei). These birds are all similar in appearance and behavior, with small, round bodies, short wings, and strong legs that are adapted for running and scratching in leaf litter. They are also known for their cryptic coloration, which helps them blend in with their surroundings and avoid predators. Quails are popular game birds and are also kept as pets and for ornamental purposes in some parts of the world.

A "gene" is a basic unit of heredity in living organisms. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for the development and function of an organism. Genes are responsible for inherited traits, such as eye color, hair color, and height, as well as susceptibility to certain diseases.

"Pol" is short for "polymerase," which is an enzyme that helps synthesize DNA or RNA (ribonucleic acid). In the context of genes, "pol" often refers to "DNA polymerase," an enzyme that plays a crucial role in DNA replication and repair.

Therefore, "genes, pol" may refer to the genes involved in the regulation or function of DNA polymerases. These genes are essential for maintaining the integrity and stability of an organism's genome. Mutations in these genes can lead to various genetic disorders and cancer.

Marek's disease is a highly contagious viral infection that primarily affects chickens and other members of the Galliformes order (which includes turkeys, quails, and pheasants). The disease is caused by the alphaherpesvirus known as Gallid herpesvirus 2 or Marek's disease virus (MDV).

The infection primarily targets the chicken's immune system, leading to various clinical manifestations such as:

1. T-cell lymphomas (cancerous growths) in the peripheral nerves, visceral organs, and skin. These tumors can cause paralysis, especially in the legs, and affect the bird's mobility and overall health.
2. Enlarged, pale, or discolored spleens and livers due to the proliferation of infected lymphocytes.
3. Lesions on the feather follicles, skin, and eyes (such as iritis, conjunctivitis, and blindness) caused by viral replication in these areas.
4. Immunosuppression, which makes affected birds more susceptible to secondary bacterial or viral infections, leading to a decline in overall health and production.

Marek's disease is primarily transmitted through the inhalation of dust particles containing infected dander or feather follicle epithelium. The virus can also be spread via contaminated equipment, clothing, and transportation vehicles.

Vaccination is an effective method to control Marek's disease in commercial poultry operations. However, the continuous evolution of more virulent strains poses a challenge for long-term protection and eradication efforts.

A provirus is a form of the genetic material of a retrovirus that is integrated into the DNA of the host cell it has infected. Once integrated, the provirus is replicated along with the host's own DNA every time the cell divides, and it becomes a permanent part of the host's genome.

The process of integration involves the reverse transcription of the retroviral RNA genome into DNA by the enzyme reverse transcriptase, followed by the integration of the resulting double-stranded proviral DNA into the host chromosome by the enzyme integrase.

Proviruses can remain dormant and inactive for long periods of time, or they can become active and produce new viral particles that can infect other cells. In some cases, proviruses can also disrupt the normal functioning of host genes, leading to various diseases such as cancer.

"Genes x Environment" (GxE) is a term used in the field of genetics to describe the interaction between genetic factors and environmental influences on the development, expression, and phenotypic outcome of various traits, disorders, or diseases. This concept recognizes that both genes and environment play crucial roles in shaping an individual's health and characteristics, and that these factors do not act independently but rather interact with each other in complex ways.

GxE interactions can help explain why some individuals with a genetic predisposition for a particular disorder may never develop the condition, while others without such a predisposition might. The environmental factors involved in GxE interactions can include lifestyle choices (such as diet and exercise), exposure to toxins or pollutants, social experiences, and other external conditions that can influence gene expression and overall health outcomes.

Understanding GxE interactions is essential for developing personalized prevention and treatment strategies, as it allows healthcare providers to consider both genetic and environmental factors when assessing an individual's risk for various disorders or diseases.

A hemangioma is a benign (noncancerous) vascular tumor or growth that originates from blood vessels. It is characterized by an overgrowth of endothelial cells, which line the interior surface of blood vessels. Hemangiomas can occur in various parts of the body, but they are most commonly found on the skin and mucous membranes.

Hemangiomas can be classified into two main types:

1. Capillary hemangioma (also known as strawberry hemangioma): This type is more common and typically appears during the first few weeks of life. It grows rapidly for several months before gradually involuting (or shrinking) on its own, usually within the first 5 years of life. Capillary hemangiomas can be superficial, appearing as a bright red, raised lesion on the skin, or deep, forming a bluish, compressible mass beneath the skin.

2. Cavernous hemangioma: This type is less common and typically appears during infancy or early childhood. It consists of large, dilated blood vessels and can occur in various organs, including the skin, liver, brain, and gastrointestinal tract. Cavernous hemangiomas on the skin appear as a rubbery, bluish mass that does not typically involute like capillary hemangiomas.

Most hemangiomas do not require treatment, especially if they are small and not causing any significant problems. However, in cases where hemangiomas interfere with vital functions, impair vision or hearing, or become infected, various treatments may be considered, such as medication (e.g., corticosteroids, propranolol), laser therapy, surgical excision, or embolization.

Viral DNA refers to the genetic material present in viruses that consist of DNA as their core component. Deoxyribonucleic acid (DNA) is one of the two types of nucleic acids that are responsible for storing and transmitting genetic information in living organisms. Viruses are infectious agents much smaller than bacteria that can only replicate inside the cells of other organisms, called hosts.

Viral DNA can be double-stranded (dsDNA) or single-stranded (ssDNA), depending on the type of virus. Double-stranded DNA viruses have a genome made up of two complementary strands of DNA, while single-stranded DNA viruses contain only one strand of DNA.

Examples of dsDNA viruses include Adenoviruses, Herpesviruses, and Poxviruses, while ssDNA viruses include Parvoviruses and Circoviruses. Viral DNA plays a crucial role in the replication cycle of the virus, encoding for various proteins necessary for its multiplication and survival within the host cell.

Lymphoma is a type of cancer that originates from the white blood cells called lymphocytes, which are part of the immune system. These cells are found in various parts of the body such as the lymph nodes, spleen, bone marrow, and other organs. Lymphoma can be classified into two main types: Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL).

HL is characterized by the presence of a specific type of abnormal lymphocyte called Reed-Sternberg cells, while NHL includes a diverse group of lymphomas that lack these cells. The symptoms of lymphoma may include swollen lymph nodes, fever, night sweats, weight loss, and fatigue.

The exact cause of lymphoma is not known, but it is believed to result from genetic mutations in the lymphocytes that lead to uncontrolled cell growth and division. Exposure to certain viruses, chemicals, and radiation may increase the risk of developing lymphoma. Treatment options for lymphoma depend on various factors such as the type and stage of the disease, age, and overall health of the patient. Common treatments include chemotherapy, radiation therapy, immunotherapy, and stem cell transplantation.

I'm sorry for any confusion, but there seems to be a mistake in the terminology you provided. There is no virus known as "Herpesvirus 2, Gallid." However, I can provide some information on a related topic.

Gallid herpesvirus 2 (GaHV-2), also known as Marek's disease virus (MDV), is a member of the Herpesviridae family and is a significant pathogen in chickens. It causes Marek's disease, a lymphoproliferative disorder that results in various clinical manifestations such as T-cell lymphomas, neurological disorders, and immunosuppression. GaHV-2 is not known to infect or cause disease in humans or other mammalian species.

If you meant to ask about human herpesviruses, please let me know and provide the correct name so I can offer an accurate definition.

Histiocytic sarcoma is a rare type of cancer that originates from histiocytes, which are cells that are part of the immune system and found in various tissues throughout the body. These cells normally function to help fight infection and remove foreign substances. In histiocytic sarcoma, there is an abnormal accumulation and proliferation of these cells, leading to the formation of tumors.

Histiocytic sarcoma can affect people of any age but is more commonly found in adults, with a slight male predominance. It can occur in various parts of the body, such as the lymph nodes, skin, soft tissues, and internal organs like the spleen, liver, and lungs. The exact cause of histiocytic sarcoma remains unknown, but it is not considered to be hereditary.

The symptoms of histiocytic sarcoma depend on the location and extent of the tumor(s). Common signs include swollen lymph nodes, fatigue, fever, weight loss, night sweats, and pain or discomfort in the affected area. Diagnosis typically involves a combination of imaging studies (like CT scans, PET scans, or MRI), biopsies, and laboratory tests to confirm the presence of histiocytic sarcoma and assess its extent.

Treatment for histiocytic sarcoma usually involves a multidisciplinary approach, including surgery, radiation therapy, and chemotherapy. The choice of treatment depends on several factors, such as the location and stage of the disease, the patient's overall health, and their personal preferences. Clinical trials may also be an option for some patients, allowing them to access new and experimental therapies.

Prognosis for histiocytic sarcoma is generally poor, with a five-year survival rate of approximately 15-30%. However, outcomes can vary significantly depending on individual factors, such as the patient's age, the extent of the disease at diagnosis, and the effectiveness of treatment. Continued research is necessary to improve our understanding of this rare cancer and develop more effective therapies for those affected.

"Gag" is a term that refers to a group of genes found in retroviruses, a type of virus that includes HIV (human immunodeficiency virus). These genes encode proteins that play a crucial role in the replication and packaging of the viral genome into new virus particles.

The "gag" gene encodes a polyprotein, which is cleaved by viral proteases into several individual proteins during the maturation of the virus. The resulting proteins include matrix (MA), capsid (CA), and nucleocapsid (NC) proteins, as well as smaller peptides that help to facilitate the assembly and release of new virus particles.

The gag gene is an essential component of retroviruses, and its function has been extensively studied in order to better understand the replication cycle of these viruses and to develop potential therapies for retroviral infections.

Avian myeloblastosis virus (AMV) is a type of retrovirus that primarily infects birds, particularly chickens. It is named after the disease it causes, avian myeloblastosis, which is a malignant condition affecting the bone marrow and blood cells of infected birds.

AMV is classified as an alpharetrovirus and has a single-stranded RNA genome. When the virus infects a host cell, its RNA genome is reverse transcribed into DNA, which then integrates into the host's chromosomal DNA. This integrated viral DNA, known as a provirus, can then direct the production of new virus particles.

AMV has been extensively studied as a model system for retroviruses and has contributed significantly to our understanding of their replication and pathogenesis. The virus is also used in laboratory research as a tool for generating genetically modified animals and for studying the regulation of gene expression. However, it is not known to infect or cause disease in humans or other mammals.

Helper viruses, also known as "auxiliary" or "satellite" viruses, are defective viruses that depend on the assistance of a second virus, called a helper virus, to complete their replication cycle. They lack certain genes that are essential for replication, and therefore require the helper virus to provide these functions.

Helper viruses are often found in cases of dual infection, where both the helper virus and the dependent virus infect the same cell. The helper virus provides the necessary enzymes and proteins for the helper virus to replicate, package its genome into new virions, and bud off from the host cell.

One example of a helper virus is the hepatitis B virus (HBV), which can serve as a helper virus for hepatitis D virus (HDV) infection. HDV is a defective RNA virus that requires the HBV surface antigen to form an envelope around its nucleocapsid and be transmitted to other cells. In the absence of HBV, HDV cannot replicate or cause disease.

Understanding the role of helper viruses in viral infections is important for developing effective treatments and vaccines against viral diseases.

Repetitive sequences in nucleic acid refer to repeated stretches of DNA or RNA nucleotide bases that are present in a genome. These sequences can vary in length and can be arranged in different patterns such as direct repeats, inverted repeats, or tandem repeats. In some cases, these repetitive sequences do not code for proteins and are often found in non-coding regions of the genome. They can play a role in genetic instability, regulation of gene expression, and evolutionary processes. However, certain types of repeat expansions have been associated with various neurodegenerative disorders and other human diseases.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Viral genes refer to the genetic material present in viruses that contains the information necessary for their replication and the production of viral proteins. In DNA viruses, the genetic material is composed of double-stranded or single-stranded DNA, while in RNA viruses, it is composed of single-stranded or double-stranded RNA.

Viral genes can be classified into three categories: early, late, and structural. Early genes encode proteins involved in the replication of the viral genome, modulation of host cell processes, and regulation of viral gene expression. Late genes encode structural proteins that make up the viral capsid or envelope. Some viruses also have structural genes that are expressed throughout their replication cycle.

Understanding the genetic makeup of viruses is crucial for developing antiviral therapies and vaccines. By targeting specific viral genes, researchers can develop drugs that inhibit viral replication and reduce the severity of viral infections. Additionally, knowledge of viral gene sequences can inform the development of vaccines that stimulate an immune response to specific viral proteins.

Culture techniques are methods used in microbiology to grow and multiply microorganisms, such as bacteria, fungi, or viruses, in a controlled laboratory environment. These techniques allow for the isolation, identification, and study of specific microorganisms, which is essential for diagnostic purposes, research, and development of medical treatments.

The most common culture technique involves inoculating a sterile growth medium with a sample suspected to contain microorganisms. The growth medium can be solid or liquid and contains nutrients that support the growth of the microorganisms. Common solid growth media include agar plates, while liquid growth media are used for broth cultures.

Once inoculated, the growth medium is incubated at a temperature that favors the growth of the microorganisms being studied. During incubation, the microorganisms multiply and form visible colonies on the solid growth medium or turbid growth in the liquid growth medium. The size, shape, color, and other characteristics of the colonies can provide important clues about the identity of the microorganism.

Other culture techniques include selective and differential media, which are designed to inhibit the growth of certain types of microorganisms while promoting the growth of others, allowing for the isolation and identification of specific pathogens. Enrichment cultures involve adding specific nutrients or factors to a sample to promote the growth of a particular type of microorganism.

Overall, culture techniques are essential tools in microbiology and play a critical role in medical diagnostics, research, and public health.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Defective viruses are viruses that have lost the ability to complete a full replication cycle and produce progeny virions independently. These viruses require the assistance of a helper virus, which provides the necessary functions for replication. Defective viruses can arise due to mutations, deletions, or other genetic changes that result in the loss of essential genes. They are often non-infectious and cannot cause disease on their own, but they may interfere with the replication of the helper virus and modulate the course of infection. Defective viruses can be found in various types of viruses, including retroviruses, bacteriophages, and DNA viruses.

Oncogenes are genes that have the potential to cause cancer. They can do this by promoting cell growth and division (cellular proliferation), preventing cell death (apoptosis), or enabling cells to invade surrounding tissue and spread to other parts of the body (metastasis). Oncogenes can be formed when normal genes, called proto-oncogenes, are mutated or altered in some way. This can happen as a result of exposure to certain chemicals or radiation, or through inherited genetic mutations. When activated, oncogenes can contribute to the development of cancer by causing cells to divide and grow in an uncontrolled manner.

A viral RNA (ribonucleic acid) is the genetic material found in certain types of viruses, as opposed to viruses that contain DNA (deoxyribonucleic acid). These viruses are known as RNA viruses. The RNA can be single-stranded or double-stranded and can exist as several different forms, such as positive-sense, negative-sense, or ambisense RNA. Upon infecting a host cell, the viral RNA uses the host's cellular machinery to translate the genetic information into proteins, leading to the production of new virus particles and the continuation of the viral life cycle. Examples of human diseases caused by RNA viruses include influenza, COVID-19 (SARS-CoV-2), hepatitis C, and polio.

Endogenous retroviruses (ERVs) are DNA sequences that have integrated into the genome of germ cells and are therefore passed down from parent to offspring through generations. These sequences are the remnants of ancient retroviral infections, where the retrovirus has become a permanent part of the host's genetic material.

Retroviruses are RNA viruses that replicate by reverse transcribing their RNA genome into DNA and integrating it into the host cell's genome. When this integration occurs in the germ cells, the retroviral DNA becomes a permanent part of the host organism's genome and is passed down to future generations.

Over time, many ERVs have accumulated mutations that render them unable to produce infectious viral particles. However, some ERVs remain capable of producing functional viral proteins and RNA, and may even be able to produce infectious viral particles under certain conditions. These active ERVs can play a role in various biological processes, both beneficial and detrimental, such as regulating gene expression, contributing to genome instability, and potentially causing disease.

It is estimated that up to 8% of the human genome consists of endogenous retroviral sequences, making them an important component of our genetic makeup.

RNA-directed DNA polymerase is a type of enzyme that can synthesize DNA using an RNA molecule as a template. This process is called reverse transcription, and it is the mechanism by which retroviruses, such as HIV, replicate their genetic material. The enzyme responsible for this reaction in retroviruses is called reverse transcriptase.

Reverse transcriptase is an important target for antiretroviral therapy used to treat HIV infection and AIDS. In addition to its role in viral replication, RNA-directed DNA polymerase also has applications in molecular biology research, such as in the production of complementary DNA (cDNA) copies of RNA molecules for use in downstream applications like cloning and sequencing.

Tenosynovitis is a medical condition characterized by inflammation of the lining (synovium) surrounding a tendon, which is a cord-like structure that attaches muscle to bone. This inflammation can cause pain, swelling, and difficulty moving the affected joint. Tenosynovitis often affects the hands, wrists, feet, and ankles, and it can result from various causes, including infection, injury, overuse, or autoimmune disorders like rheumatoid arthritis. Prompt diagnosis and treatment of tenosynovitis are essential to prevent complications such as tendon rupture or chronic pain.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Viral interference is a phenomenon where the replication of one virus is inhibited or blocked by the presence of another virus. This can occur when two different viruses infect the same cell and compete for the cell's resources, such as nucleotides, energy, and replication machinery. As a result, the replication of one virus may be suppressed, allowing the other virus to predominate.

This phenomenon has been observed in both in vitro (laboratory) studies and in vivo (in the body) studies. It has been suggested that viral interference may play a role in the outcome of viral coinfections, where an individual is infected with more than one virus at the same time. Viral interference can also be exploited as a potential strategy for antiviral therapy, where one virus is used to inhibit the replication of another virus.

It's important to note that not all viruses interfere with each other, and the outcome of viral coinfections can depend on various factors such as the specific viruses involved, the timing and sequence of infection, and the host's immune response.

Virus replication is the process by which a virus produces copies or reproduces itself inside a host cell. This involves several steps:

1. Attachment: The virus attaches to a specific receptor on the surface of the host cell.
2. Penetration: The viral genetic material enters the host cell, either by invagination of the cell membrane or endocytosis.
3. Uncoating: The viral genetic material is released from its protective coat (capsid) inside the host cell.
4. Replication: The viral genetic material uses the host cell's machinery to produce new viral components, such as proteins and nucleic acids.
5. Assembly: The newly synthesized viral components are assembled into new virus particles.
6. Release: The newly formed viruses are released from the host cell, often through lysis (breaking) of the cell membrane or by budding off the cell membrane.

The specific mechanisms and details of virus replication can vary depending on the type of virus. Some viruses, such as DNA viruses, use the host cell's DNA polymerase to replicate their genetic material, while others, such as RNA viruses, use their own RNA-dependent RNA polymerase or reverse transcriptase enzymes. Understanding the process of virus replication is important for developing antiviral therapies and vaccines.

Retroviridae is a family of viruses that includes human immunodeficiency virus (HIV) and other viruses that primarily use RNA as their genetic material. The name "retrovirus" comes from the fact that these viruses reverse transcribe their RNA genome into DNA, which then becomes integrated into the host cell's genome. This is a unique characteristic of retroviruses, as most other viruses use DNA as their genetic material.

Retroviruses can cause a variety of diseases in animals and humans, including cancer, neurological disorders, and immunodeficiency syndromes like AIDS. They have a lipid membrane envelope that contains glycoprotein spikes, which allow them to attach to and enter host cells. Once inside the host cell, the viral RNA is reverse transcribed into DNA by the enzyme reverse transcriptase, which is then integrated into the host genome by the enzyme integrase.

Retroviruses can remain dormant in the host genome for extended periods of time, and may be reactivated under certain conditions to produce new viral particles. This ability to integrate into the host genome has also made retroviruses useful tools in molecular biology, where they are used as vectors for gene therapy and other genetic manipulations.

Genetic recombination is the process by which genetic material is exchanged between two similar or identical molecules of DNA during meiosis, resulting in new combinations of genes on each chromosome. This exchange occurs during crossover, where segments of DNA are swapped between non-sister homologous chromatids, creating genetic diversity among the offspring. It is a crucial mechanism for generating genetic variability and facilitating evolutionary change within populations. Additionally, recombination also plays an essential role in DNA repair processes through mechanisms such as homologous recombinational repair (HRR) and non-homologous end joining (NHEJ).

Bovine Leukemia Virus (BLV) is a retrovirus that infects cattle and causes enzootic bovine leukosis, a neoplastic disease characterized by the proliferation of malignant B-lymphocytes. The virus primarily targets the animal's immune system, leading to a decrease in the number of white blood cells (leukopenia) and an increased susceptibility to other infections.

The virus is transmitted horizontally through close contact with infected animals or vertically from mother to offspring via infected milk or colostrum. The majority of BLV-infected cattle remain asymptomatic carriers, but a small percentage develop clinical signs such as lymphoma, weight loss, and decreased milk production.

BLV is closely related to human T-cell leukemia virus (HTLV), and both viruses belong to the Retroviridae family, genus Deltaretrovirus. However, it's important to note that BLV does not cause leukemia or any other neoplastic diseases in humans.

Virus integration, in the context of molecular biology and virology, refers to the insertion of viral genetic material into the host cell's genome. This process is most commonly associated with retroviruses, such as HIV (Human Immunodeficiency Virus), which have an enzyme called reverse transcriptase that converts their RNA genome into DNA. This DNA can then integrate into the host's chromosomal DNA, becoming a permanent part of the host's genetic material.

This integration is a crucial step in the retroviral life cycle, allowing the virus to persist within the host cell and evade detection by the immune system. It also means that the viral genome can be passed on to daughter cells when the host cell divides.

However, it's important to note that not all viruses integrate their genetic material into the host's genome. Some viruses, like influenza, exist as separate entities within the host cell and do not become part of the host's DNA.

Cell transformation, viral refers to the process by which a virus causes normal cells to become cancerous or tumorigenic. This occurs when the genetic material of the virus integrates into the DNA of the host cell and alters its regulation, leading to uncontrolled cell growth and division. Some viruses known to cause cell transformation include human papillomavirus (HPV), hepatitis B virus (HBV), and certain types of herpesviruses.

Retroviridae is a family of viruses that includes HIV (Human Immunodeficiency Virus). Retroviridae proteins refer to the various structural and functional proteins that are encoded by the retroviral genome. These proteins can be categorized into three main groups:

1. Group-specific antigen (Gag) proteins: These proteins make up the viral matrix, capsid, and nucleocapsid. They are involved in the assembly of new virus particles.

2. Polymerase (Pol) proteins: These proteins include the reverse transcriptase, integrase, and protease enzymes. Reverse transcriptase is responsible for converting the viral RNA genome into DNA, which can then be integrated into the host cell's genome by the integrase enzyme. The protease enzyme is involved in processing the polyprotein precursors of Gag and Pol into their mature forms.

3. Envelope (Env) proteins: These proteins are responsible for the attachment and fusion of the virus to the host cell membrane. They are synthesized as a precursor protein, which is then cleaved by a host cell protease to form two distinct proteins - the surface unit (SU) and the transmembrane unit (TM). The SU protein contains the receptor-binding domain, while the TM protein forms the transmembrane anchor.

Retroviral proteins play crucial roles in various stages of the viral life cycle, including entry, reverse transcription, integration, transcription, translation, assembly, and release. Understanding the functions of these proteins is essential for developing effective antiretroviral therapies and vaccines against retroviral infections.

I am not aware of a medical definition for the term "birds." Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, and lightweight but strong skeletons. Some birds, such as pigeons and chickens, have been used in medical research, but the term "birds" itself does not have a specific medical definition.

Viral envelope proteins are structural proteins found in the envelope that surrounds many types of viruses. These proteins play a crucial role in the virus's life cycle, including attachment to host cells, fusion with the cell membrane, and entry into the host cell. They are typically made up of glycoproteins and are often responsible for eliciting an immune response in the host organism. The exact structure and function of viral envelope proteins vary between different types of viruses.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Neoplastic cell transformation is a process in which a normal cell undergoes genetic alterations that cause it to become cancerous or malignant. This process involves changes in the cell's DNA that result in uncontrolled cell growth and division, loss of contact inhibition, and the ability to invade surrounding tissues and metastasize (spread) to other parts of the body.

Neoplastic transformation can occur as a result of various factors, including genetic mutations, exposure to carcinogens, viral infections, chronic inflammation, and aging. These changes can lead to the activation of oncogenes or the inactivation of tumor suppressor genes, which regulate cell growth and division.

The transformation of normal cells into cancerous cells is a complex and multi-step process that involves multiple genetic and epigenetic alterations. It is characterized by several hallmarks, including sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, enabling replicative immortality, induction of angiogenesis, activation of invasion and metastasis, reprogramming of energy metabolism, and evading immune destruction.

Neoplastic cell transformation is a fundamental concept in cancer biology and is critical for understanding the molecular mechanisms underlying cancer development and progression. It also has important implications for cancer diagnosis, prognosis, and treatment, as identifying the specific genetic alterations that underlie neoplastic transformation can help guide targeted therapies and personalized medicine approaches.

A Cytopathic Effect (CPE) is a visible change in the cell or group of cells due to infection by a pathogen, such as a virus. When the cytopathic effect is caused specifically by a viral infection, it is referred to as a "Viral Cytopathic Effect" (VCPE).

The VCPE can include various changes in the cell's morphology, size, and structure, such as rounding, shrinkage, multinucleation, inclusion bodies, and formation of syncytia (multinucleated giant cells). These changes are often used to identify and characterize viruses in laboratory settings.

The VCPE is typically observed under a microscope after the virus has infected cell cultures, and it can help researchers determine the type of virus, the degree of infection, and the effectiveness of antiviral treatments. The severity and timing of the VCPE can vary depending on the specific virus and the type of cells that are infected.

A genetic vector is a vehicle, often a plasmid or a virus, that is used to introduce foreign DNA into a host cell as part of genetic engineering or gene therapy techniques. The vector contains the desired gene or genes, along with regulatory elements such as promoters and enhancers, which are needed for the expression of the gene in the target cells.

The choice of vector depends on several factors, including the size of the DNA to be inserted, the type of cell to be targeted, and the efficiency of uptake and expression required. Commonly used vectors include plasmids, adenoviruses, retroviruses, and lentiviruses.

Plasmids are small circular DNA molecules that can replicate independently in bacteria. They are often used as cloning vectors to amplify and manipulate DNA fragments. Adenoviruses are double-stranded DNA viruses that infect a wide range of host cells, including human cells. They are commonly used as gene therapy vectors because they can efficiently transfer genes into both dividing and non-dividing cells.

Retroviruses and lentiviruses are RNA viruses that integrate their genetic material into the host cell's genome. This allows for stable expression of the transgene over time. Lentiviruses, a subclass of retroviruses, have the advantage of being able to infect non-dividing cells, making them useful for gene therapy applications in post-mitotic tissues such as neurons and muscle cells.

Overall, genetic vectors play a crucial role in modern molecular biology and medicine, enabling researchers to study gene function, develop new therapies, and modify organisms for various purposes.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

Nucleic acid hybridization is a process in molecular biology where two single-stranded nucleic acids (DNA, RNA) with complementary sequences pair together to form a double-stranded molecule through hydrogen bonding. The strands can be from the same type of nucleic acid or different types (i.e., DNA-RNA or DNA-cDNA). This process is commonly used in various laboratory techniques, such as Southern blotting, Northern blotting, polymerase chain reaction (PCR), and microarray analysis, to detect, isolate, and analyze specific nucleic acid sequences. The hybridization temperature and conditions are critical to ensure the specificity of the interaction between the two strands.

An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Viral antigens are antigens that are found on or produced by viruses. They can be proteins, glycoproteins, or carbohydrates present on the surface or inside the viral particle.

Viral antigens play a crucial role in the immune system's recognition and response to viral infections. When a virus infects a host cell, it may display its antigens on the surface of the infected cell. This allows the immune system to recognize and target the infected cells for destruction, thereby limiting the spread of the virus.

Viral antigens are also important targets for vaccines. Vaccines typically work by introducing a harmless form of a viral antigen to the body, which then stimulates the production of antibodies and memory T-cells that can recognize and respond quickly and effectively to future infections with the actual virus.

It's worth noting that different types of viruses have different antigens, and these antigens can vary between strains of the same virus. This is why there are often different vaccines available for different viral diseases, and why flu vaccines need to be updated every year to account for changes in the circulating influenza virus strains.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

A viral genome is the genetic material (DNA or RNA) that is present in a virus. It contains all the genetic information that a virus needs to replicate itself and infect its host. The size and complexity of viral genomes can vary greatly, ranging from a few thousand bases to hundreds of thousands of bases. Some viruses have linear genomes, while others have circular genomes. The genome of a virus also contains the information necessary for the virus to hijack the host cell's machinery and use it to produce new copies of the virus. Understanding the genetic makeup of viruses is important for developing vaccines and antiviral treatments.

... is characterized by a wide range of tumors, the most common of which are lymphomas. Lymphoid ... Avian sarcoma leukosis virus (ASLV) is an endogenous retrovirus that infects and can lead to cancer in chickens; experimentally ... The American Association of Avian Pathologists maintains a fact sheet on viral tumor diseases. "Leukosis/Sarcoma Group". The ... ISBN 978-1-118-71973-2. Riddell, C. (May-June 1999). "The current problem with Avian Leukosis J Virus". California Poultry ...
"The Poultry Guide - Avian Lymphoid Leukosis". Archived from the original on 2017-12-11. Retrieved 2007-12-12. v t e (Articles ... Lymphoid leucosis is a disease that affects chickens, caused by the retrovirus Avian leukosis virus. It is a neoplastic disease ...
This family now includes the following genera: Subfamily Orthoretrovirinae: Genus Alpharetrovirus; including Avian leukosis ...
Rubin, H; Vogt PK (1962). "An avian leukosis virus associated with stocks of Rous sarcoma virus". Virology. 17: 184-94. doi: ... "Patterns of viral interference in the avian leukosis and sarcoma complex". Virology. 30 (3): 368-74. doi:10.1016/0042-6822(66) ... Maki, Y; Bos TJ; Davis C; Starbuck M; Vogt PK (1987). "Avian sarcoma virus 17 carries the jun oncogene". Proc Natl Acad Sci U S ... Duesberg, PH; Bister K; Vogt PK (1977). "The RNA of avian acute leukemia virus MC29". Proc Natl Acad Sci U S A. 74 (10): 4320-4 ...
... after Marek's disease and avian leukosis virus. The various syndromes caused by REV resemble both Marek's and avian leukosis. ... The Avian Diagnostic and Oncology Laboratory, in East Lansing, MI is the primary laboratory for research in REV and other tumor ... "Avian Diagnostic and Oncology Laboratory". "Frequently Asked Questions on Viral Tumor Diseases - Compiled by the AAAP Tumor ... The American Association of Avian Pathologists maintains a fact sheet on viral tumor diseases. Swayne, David E.; Glisson, John ...
Lymphoid Leukosis A, B; Avian Lymphoid Leukosis Virus; Lymphoid Leukosis Viruses A,B,C,D,E,J; Marek's Disease (Serotypes 1,2, 3 ... Avian Nephritis Virus, Avian Paramyxovirus Type 2, Avian Reovirus S 1133, Avian Rhinotracheitis Virus; Avian Rotavirus; Avian ... Avian Adenovirus Group II (HEV), Avian Adenovirus Group III (EDS), Avian Encephalomyelitis, Avian Influenza (Type A), ... For SPF eggs the specific pathogens are: Avian Adenovirus Group I, ...
Species include the Rous sarcoma virus, avian leukosis virus, and avian myeloblastosis virus (AMV). Not all animals that can ... Perbal, Bernard (2008). "Avian myeoloblastosis virus (AMV): only one side of the coin". Retrovirology. 5 (1): 49. doi:10.1186/ ...
Curristin SM, Bird KJ, Tubbs RJ, Ruddell A (1997). "VBP and RelA regulate avian leukosis virus long terminal repeat-enhanced ...
Newly hatched chicks infected with the Avian leukosis virus will begin to form tumours that will begin to appear in their bursa ... These tumours are normally derived from one mutated/transformed cell (clonal in origin). Avian leukosis virus is an example of ...
Avian Sarcoma and Leukosis Viruses (ASLV) have ten subgroups (A through J). The envelope glycoprotein of subgroup A is called ... The Env proteins of the Avian Sarcoma and Leukosis virus (ASLV) and the Murine Leukemia Virus (MLV) are both trimers of SU-TM ... Barnard RJ, Narayan S, Dornadula G, Miller MD, Young JA (October 2004). "Low pH is required for avian sarcoma and leukosis ... Balliet JW, Gendron K, Bates P (April 2000). "Mutational analysis of the subgroup A avian sarcoma and leukosis virus putative ...
... demonstrated that avian sarcoma leukosis virus (ASLV) can act as a "helper virus" for RSV. This research earned Rubin the 1964 ... "Tolerance and immunity in chickens after congenital and contact infection with an avian leukosis virus". Virology. 17: 143-156 ...
Rous sarcoma and Avian leukosis viruses (Alpharetroviruses and Avian type C retroviruses). dr1 is required for efficient viral ... Aschoff JM, Foster D, Coffin JM (September 1999). "Point mutations in the avian sarcoma/leukosis virus 3' untranslated region ... The direct repeat 1 (dr1) element is an RNA element commonly found in the 3' UTR of Avian sarcoma, ...
Her initial focus used the avian sarcoma leukosis viruses (ASV) of chickens as a model system. With Bill McClements and others ... the laboratory cloned part of the avian endogenous provirus ev-1 as well as its integration site; the results suggested ...
She was later employed as an agent of the USDA to investigate the diseases of poultry and avian leukosis. The abbreviation ...
The work with avian leukosis sarcoma viruses also provided the foundation for her pioneering studies on recombinant DNA ... Post doctoral studies were at the University of California, Berkeley where she acquired the avian leukosis sarcoma virus model ... In 1977, she joined the Worcester Foundation for Biomedical Research where her work using avian leukosis viruses in chickens ...
The most common immunosuppressive viruses are Infectious Bursal Disease Virus (IBDV), Avian Leukosis, Marek's Disease (MD) and ... "Development of the Avian Immune System." Avian Immunology. 4:51-66. Masteller EL, Pharr GT, Funk PE, Thompson CB (1997). "Avian ... Viertlboeck B, Göbel TWF (2008). "Avian T cells: antigen recognition and lineages." Avian Immunol. 6:91-105. Kaiser P, Rothwell ... avian influenza, giardiasis and cryptosporidiosis. These zoonotic diseases can be transmitted to humans. In the case of avian ...
Bang and Ellerman demonstrated that avian sarcoma leukosis virus could be transmitted between chickens after cell-free ... Rous P (September 1910). "A Transmissible Avian Neoplasm. (Sarcoma of the Common Fowl.)". The Journal of Experimental Medicine ...
Throughout the 1950's debate raged over the causes of different syndromes within the Avian Leukosis Complex, if it was ... The two diseases, with completely different aetiologies, were included together under the general term 'Avian Leukosis Complex ... Avian Pathology, journal British Poultry Science, journal British Society of Animal Science Microbiology Society National ... 1961 saw the culmination of many years of confusion, when Biggs and Campbell proposed that the leukosis complex and fowl ...
In coinfected cells, the retroviral DNA of the avian leukosis virus can integrate into the MDV genome, producing altered ... for instance between Avian sarcoma leukosis virus and Marek's disease virus (MDV) in domestic fowl.[citation needed] Both ...
... in horses Leucosis in sheep Feline leucosis Feline leukemia virus Avian leucosis and related diseases Avian sarcoma leukosis ... ISBN 0-7020-0718-8. H. Graham Purchase and L.N. Payne, Leukosis/sarcoma Group, in Diseases of poultry, ed. by M.S. Hofstad, ...
American Literary Version Avian leukosis virus Autoliv (ticker symbol) This disambiguation page lists articles associated with ...
... avian MeSH C04.619.857.822 - sarcoma, yoshida MeSH C04.619.935.120 - avian leukosis MeSH C04.619.935.313 - epstein-barr virus ... enzootic bovine leukosis MeSH C04.557.337.372 - leukemia, experimental MeSH C04.557.337.372.216 - avian leukosis MeSH C04.557. ... avian leukosis MeSH C04.619.531.594 - leukemia L1210 MeSH C04.619.531.602 - leukemia L5178 MeSH C04.619.531.782 - leukemia p388 ... avian MeSH C04.651.600.500 - multiple endocrine neoplasia type 1 MeSH C04.651.600.505 - multiple endocrine neoplasia type 2a ...
Family 1.G.12 The Avian Leukosis Virus gp95 Fusion Protein (ALV-gp95) Family 1.G.13 The Orthoreovirus Fusion-associated Small ... 1.A.39 Type C influenza virus CM2 channel family 1.A.40 Human immunodeficiency virus type I Vpu channel family 1.A.41 Avian ...
... avian leukosis MeSH C22.131.321 - fowlpox MeSH C22.131.450 - influenza in birds MeSH C22.131.498 - malaria, avian MeSH C22.131. ... avian MeSH C22.131.921 - tuberculosis, avian MeSH C22.180.350 - feline acquired immunodeficiency syndrome MeSH C22.180.440 - ... enzootic bovine leukosis MeSH C22.196.274 - ephemeral fever MeSH C22.196.339 - freemartinism MeSH C22.196.400 - hemorrhagic ...
Concerns about temperature stability and avian sarcoma leukosis virus prevented it from being used more widely during the ...
Viruses portal Avian sarcoma leukosis virus (ASLV) Endogenous viral element Endogeny (biology) ERV3 HERV-FRD Horizontal gene ...
Ancient DNA Avian sarcoma leukosis virus (ASLV) Endogenous retrovirus ERV3 HERV-FRD Jaagsiekte sheep retrovirus (JSRV) Koala ...
... avian leukosis MeSH C02.782.815.200 - deltaretrovirus infections MeSH C02.782.815.200.260 - enzootic bovine leukosis MeSH ... avian MeSH C02.782.930.100 - alphavirus infections MeSH C02.782.930.100.370 - encephalomyelitis, equine MeSH C02.782.930.100. ...
Avian coronavirus Avian coronavirus 9203 Avian leukosis virus Avian myeloblastosis virus Avian myelocytomatosis virus 29 Avian ... orthoreovirus Avian sarcoma virus CT10 Avibirnavirus gumboroense Avihepatovirus A Avihepevirus egretti Avihepevirus magniiecur ... Aveparvovirus galliform1 Aveparvovirus gruiform1 Aveparvovirus passeriform1 Avesvirus sinense Aviadenovirus leucophthalmi Avian ...
... avian MeSH B04.820.650.070.500 - leukosis virus, avian MeSH B04.820.650.070.550 - myeloblastosis virus, avian MeSH B04.820. ... avian MeSH B04.909.574.807.070.500 - leukosis virus, avian MeSH B04.909.574.807.070.550 - myeloblastosis virus, avian MeSH ... avian MeSH B04.909.777.731.070.500 - leukosis virus, avian MeSH B04.909.777.731.070.550 - myeloblastosis virus, avian MeSH ... avian MeSH B04.820.565.400.410 - hepatitis a virus MeSH B04.820.565.400.410.500 - hepatitis a virus, human MeSH B04.820.565.700 ...
Avian sarcoma leukosis virus is characterized by a wide range of tumors, the most common of which are lymphomas. Lymphoid ... Avian sarcoma leukosis virus (ASLV) is an endogenous retrovirus that infects and can lead to cancer in chickens; experimentally ... The American Association of Avian Pathologists maintains a fact sheet on viral tumor diseases. "Leukosis/Sarcoma Group". The ... ISBN 978-1-118-71973-2. Riddell, C. (May-June 1999). "The current problem with Avian Leukosis J Virus". California Poultry ...
Recovery of acutely transforming viruses from myeloid leukosis induced by the HPRS-103 strain of avian leukosis virus. Avian ... Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China. Avian Pathol. 2004;33:13-7. DOIPubMedGoogle ... Emerging of avian leukosis virus subgroup J in a flock of Chinese local breed [in Chinese]. Acta Microbiol Sin. 2005;45:584-7. ... HPRS-103 (exogenous avian leukosis virus, subgroup J) has an env gene related to those of endogenous elements EAV-0 and E51 and ...
Avian leukosis virus (ALV) infects mainly chickens but can also infect pheasants, partridges and quail. It belongs to the ... Avian leukosis virus. Avian leukosis virus (ALV) infects mainly chickens but can also infect pheasants, partridges and quail. ... Avian Leukosis Virus. Molecular Detection of Animal Viral Pathogens (edited by Lui Dongyou, CRC Press) chapter 17 , 145-156 ... Precise gene editing of chicken Na+/H+ exchange type 1 (chNHE1) confers resistance to avian leukosis virus subgroup J (ALV-J). ...
The HPRS-103 strain of avian leukosis virus (ALV) was isolated recently from meat-type chickens and represents a new envelope ... Recovery of acutely transforming viruses from myeloid leukosis induced by the HPRS-103 strain of avian leukosis virus. Payne LN ... Isolation and some characteristics of a subgroup J-like avian leukosis virus associated with myeloid leukosis in meat-type ... Myeloid leukaemogenicity and transmission of the HPRS-103 strain of avian leukosis virus L N Payne 1 , A M Gillespie, K Howes ...
ALV-J causes predominantly myeloid leukosis, with variable tumor frequency across chicken lines ... Avian Leukosis Virus (ALV). Lymphoid leukosis, the most common manifestation of the avian leukosis/sarcoma group of viruses, ... Avian Leukosis Virus (ALV). ALV-J is an avian retrovirus first isolated in meat-type chickens in the late 1980s, and is ... The emergence of subgroup J avian leukosis virus. Avian Pathology. 1998;27:36-45. ...
Recovery of acutely transforming viruses from myeloid leukosis induced by the HPRS-103 strain of avian leukosis virus. Avian ... Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China. Avian Pathol. 2004;33:13-7. DOIPubMedGoogle ... Emerging of avian leukosis virus subgroup J in a flock of Chinese local breed [in Chinese]. Acta Microbiol Sin. 2005;45:584-7. ... HPRS-103 (exogenous avian leukosis virus, subgroup J) has an env gene related to those of endogenous elements EAV-0 and E51 and ...
Vectors derived from avian leukosis and sarcoma viruses. F. Flamant, F. L Cosset, and J. Samarut (1995) ... Vectors derived from avian leukosis and sarcoma viruses ...
Instead of Kentucky-fried or tacos con pollo, theyre serving up "Chicken á la Avian Leukosis." Thats chicken infected with a ... 47-28B-Trump-dishes-up-Chicken-a-la-Avian-Leukosis.docx 14 KB 0 downloads ...
Reverse transcriptase activity in avian leucosis virus LEUKOSIS VIRUS, AVIAN /*enzymol REVERSE TRANSCRIPTASE /*metab ...
Avian Leukosis. Oncogenes. Genre(s):. Archival Materials. Abstracts (summaries). Abstract:. Varmus and Nusse here gave a ... Oncogenesis without Viral Oncogenes by Avian Leukosis and Mouse Mammary Tumor Viruses. Contributor(s):. Varmus, Harold. ...
ASLV: Avian sarcoma/leukosis virus; HTLV-I: Human T-lymphotropic virus; MoMLV: Moloney murine leukemia virus; RSV: Rous-Sarcoma ... ASLV: Avian sarcoma/leukosis virus; HTLV-I: Human T-lymphotropic virus; MoMLV: Moloney murine leukemia virus; RSV: Rous-Sarcoma ...
The detection of the avian leukosis virus (ALV) p27 antigen plays a decisive role in the elimination of avian leukosis. To ... Avian leukosis (AL) is one of the most harmful diseases to the poultry industry in China. ... Avian leukosis (AL) is one of the most harmful diseases to the poultry industry in China. The detection of the avian leukosis ... Avian leukosis (AL) is caused by the avian leukosis virus (ALV), which is associated with a variety of malignant neoplasms, ...
The pathogenesis of immunological tolerance caused by avian leukosis virus subgroup J (ALV-J), an oncogenic retrovirus, is ... Avian endogenous retrovirus EAV-HP shares regions of identity with avian leukosis virus subgroup J and the avian ... Avian leukosis virus subgroup J (ALV-J), an oncogenic retrovirus, causes myeloid leukosis and various other neoplastic diseases ... Response of white leghorn chickens of various genetic lines to infection with avian leukosis virus subgroup. J Avian Dis. 2004; ...
Molecular identification of avian leukosis virus subgroup E loci and tumor virus B locus in Chinese indigenous chickens. Poult ... The CAR1 gene encoding a cellular receptor specific for subgroup b and d avian leukosis viruses maps to the chicken tvb locus ... A fifteen-amino-acid TVB peptide serves as a minimal soluble receptor for subgroup B avian leukosis and sarcoma viruses. J ... Amino acid residues Tyr-67, Asn-72, and Asp-73 of the TVB receptor are important for subgroup E avian sarcoma and leukosis ...
Parainfluenza 1, 2, 3, SV-5; avian leukosis (RSV/RIF and RSV-Harris); SV-41, measles, mumps, respiratory syncitial, rubella, ...
Avian leukosis virus. Marburg-like Viruses. Marburgvirus. Mareks Disease-like Viruses ...
Research Project: Effect of Mareks Disease CVRM Vaccine on the Enhancement of Spontaneous Avian Leukosis-like Tumors Location ... This proposal aims to evaluate whether the CVRM vaccine causes enhancement of spontaneous avian leukosis-like tumors in Line ... The Avian Disease & Oncology Laboratory maintains a genetic line of chickens, Line ALV-6, that is prone to a small incidence of ...
Ziemiecki A, Kromer G, Mueller RG, Hala K, Wick G: ev 22, a new endogenous avian leukosis virus locus found in chickens with ...
Avian leukosis virus overview. Kingdom: Viruses. ; Subgroup: Retroviridae. Sequence data: genome assemblies:. 2. Date: 1993/04/ ...
Infrequent involvement of c-fos in avian leukosis virus-induced nephroblastoma.. Collart KL; Aurigemma R; Smith RE; Kawai S; ...
These two lines of chickens are free of subgroup E avian leukosis virus (commonly referred to as endogenous virus free or ev ... ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Avian Disease and Oncology Research » ... Technical Abstract: Two of the chicken lines that USDA-ARS Avian Disease & Oncology Laboratory (ADOL) have developed and ...
Avian sarcoma leukosis virus (ASLV) is an endogenous (having an internal cause) retrovirus that infects the bird and can lead ... Part VI: Determining and Managing the Care of the Avian Cancer Patient. In: Avian Health and Disease ... Section I: Clinical Avian Neoplasia and Oncology in Clinical Avian Medicine 2006). ... The avian veterinarian would need to "pull the shafts and cauterize the germinal base to prevent the feathers from growing back ...
Molecular analysis of the c-myc locus in normal tissue and in avian leukosis virus-induced lymphomas. Neel, B.G., Gasic, G.P., ... We isolated molecular clones of the provirus-host cell junctions (tumor junction fragments) from two avian leukosis virus- ...
He was beginning, also, to be interested in the leukosis viruses, the avian leukosis viruses, and the murine C-type viruses. I ...
The viruses include avian herpesvirus, avian leukosis virus, and lymphoproliferative disease. *People who grow up on poultry ...
Irrefutable evidence does confirm that the nonhuman retroviruses avian leukosis virus (ALV), bovine leukemia virus (BLV), ...
  • In recent years, cases of avian leukosis virus subgroup J (ALV-J) infection and tumors in commercial layer chickens and breeders of egg-type chickens have been emerging in the People's Republic of China. (cdc.gov)
  • Release of group-specific antigen into the extracellular medium was independent of subgroup or strain of avian leukosis or Rous sarcoma virus. (microbiologyresearch.org)
  • The ALV-B dtec-RT-qPCR comprises a series of species-specific targeted reagents designed for detection of all serotypes of Avian leukosis virus subgroup B species by using qPCR. (geneticpcr.com)
  • Broiler parent chicks from were hatched from a grandparent flock known to be infected with avian leukosis virus subgroup J (ALV-J) and sampled at 2-4 week intervals from hatch to 60 weeks. (usda.gov)
  • The study, published in Genetics Selection Evolution , focused on Avian Leukosis Virus subgroup E (ALVE) infections and could be of greatest benefit to smallholder farms in developing countries. (wattagnet.com)
  • Subgroup J of avian leukosis virus (ALV J) was firstly isolated from commercial broiler flocks with significant clinical symptoms in Jining city of Shandong province in China by inoculating chicken embryo fibroblast cells (CEF) and using pathologic diagnosis. (cnki.net)
  • The subgroup A to E avian sarcoma and leukosis viruses (ASLVs) are highly related and are thought to have evolved from a common ancestor. (elsevierpure.com)
  • The leukosis/sarcoma (L/S) group of diseases comprise of a variety of transmissible benign and malignant neoplasms, such as lymphoid, myeloid and erythroid leukosis, caused by avian leukosis viruses (ALV), belonging to the family Retroviridae . (caister.com)
  • Multiple group specific antigen components of avian tumor viruses detected with chicken and hamster sera. (microbiologyresearch.org)
  • Complement-fixing antigens in tissue cultures of avian leukosis viruses. (microbiologyresearch.org)
  • Polypeptides of avian RNA tumor viruses. (microbiologyresearch.org)
  • Origin of group-specific antigen of chicken leukosis viruses. (microbiologyresearch.org)
  • Fluorescent antibody studies of viruses of the avian leukosis complex. (microbiologyresearch.org)
  • I. Avian leukemia-sarcoma viruses. (microbiologyresearch.org)
  • Immunofluorescent studies of group-specific antigen of the avian sarcoma-leukosis viruses. (microbiologyresearch.org)
  • Avian leukosis virus belongs to a family of viruses called retroviruses, single-stranded RNA enveloped viruses. (geneticpcr.com)
  • Poultry viruses, such as avian pox and Newcastle disease (ND), are known to have a negative impact on poultry reproductive performance 1 - 4 . (scialert.net)
  • For instance, avian pox viruses, DNA viruses, infect a wide range of domestic poultry causing a drop in egg production and impaired reproductive efficiency 3 , 4 . (scialert.net)
  • Studies conducted in the 1960s found that certain live poultry viruses, like fowl pox 17 , 18 , ND 8 , Rous sarcoma 19 and avian leukosis 20 , following either natural infection or vaccination, increased the occurrence of parthenogenesis in chickens 19 and turkeys 17 , 18 . (scialert.net)
  • These viruses use distinct cell surface proteins as receptors to gain entry into avian cells. (elsevierpure.com)
  • ALV-J was first isolated from meat-type chickens with myeloid leukosis in 1988. (cdc.gov)
  • The major group-specific antigen (gs-a) of avian leukoviruses was detected by radioimmunoassay in extracellular medium of all embryonic cultures prepared from infected chickens. (microbiologyresearch.org)
  • Embryos of birds not carrying an avian leukosis virus infection and of chickens from a leukosis-free flock could thus clearly be distinguished from infected ones. (microbiologyresearch.org)
  • Domestic chickens activate a piRNA defense against avian leukosis virus. (rochester.edu)
  • Chickens with avian leukosis virus are fit for the market, said the U.S. Department of Agriculture (USDA) in a shocking statement . (peta.org)
  • In addition, genome-edited chickens have been bred which are resistant to the avian leukosis virus. (feedstuffs.com)
  • The variant of a certain protein leading to resistance to the avian leukosis virus does not occur in chickens, but is found, for example, in quails. (feedstuffs.com)
  • The phenomenon has been observed in a variety of avian species, including chickens 9 , turkeys 10 and quail 11 . (scialert.net)
  • The National Chicken Council petitioned FSIS to allow chickens with suspected avian leukosis lesions to enter the food supply chain after trimming. (usfoodimports.com)
  • Expression of Rous sarcoma virus-derived retroviral vectors in the avian blastoderm: potential as stable genetic markers. (org.ua)
  • While A and B subgroups are primarily associated with lymphoid leukosis, ALV-J primarily induces myeloid leukosis, currently a major problem in countries such as China. (caister.com)
  • After hatch, virtually all hens became infected and about 20% developed tumors, mostly myeloid leukosis. (usda.gov)
  • Lack of relationship between infection with avian leukosis virus and the presence of COFAL antigen in chick embryos. (microbiologyresearch.org)
  • This supports the idea that ALVEs have a role in regulating host responses to further infection by Avian Leukosis Virus, and therefore may have a beneficial effect in the genome," Smith explained. (wattagnet.com)
  • Avian sarcoma leukosis virus is characterized by a wide range of tumors, the most common of which are lymphomas. (wikipedia.org)
  • Lymphoid leukosis is the most common form of this disease and with typical presentation of gradual onset, persistent low mortality, and neoplasia of the bursa. (wikipedia.org)
  • Lymphoid leukosis has a worldwide distribution, and is most commonly found in birds 16 weeks or older. (wikipedia.org)
  • Lymphoid leukosis was eradicated in primary breeders in the 1980s and 1990s which dramatically reduced the incidence of the disease in commercial laying hens. (wikipedia.org)
  • Avian Virology: Current Research and Future Trends (Edited by: Siba K. Samal). (caister.com)
  • The subgroups evolved to utilize difference cellular receptors to gain entry into avian cells due to the host developing resistance to viral entry. (wikipedia.org)
  • In the accompanying article, we presented experiments that demonstrate that polypeptides of various sizes could be efficiently displayed on the envelope glycoproteins of a eukaryotic virus, avian leukosis virus (ALV), and the displayed polypeptides could efficiently attach to cognate receptors without interfering with viral attachment and entry into susceptible cells. (elsevierpure.com)
  • Endogenous retrovirus sequences were detected by using a 32 P-labeled avian leukosis viral RNA probe. (princeton.edu)
  • RNA from an avian sarcoma virus was used to detect cellular sequences (sarc) homologous to the viral transforming gene (src). (princeton.edu)
  • USDA's FSIS and other health agencies have recognized that avian leukosis is not food safety concern and is not transmissible to humans. (chickencheck.in)
  • Integration of avian sarcoma virus DNA in chicken cells. (wikidata.org)
  • Instead of Kentucky-fried or tacos con pollo, they're serving up "Chicken á la Avian Leukosis. (jimhightower.com)
  • Avian leukosis virus (ALV) is one of causing agents for neoplastic syndrome in commercial chicken farms. (ugm.ac.id)
  • And now, thanks to a new rule the Trump administration may propose, chicken with an avian virus would be for sale in stores. (peta.org)
  • Thanks to the avian virus, a chicken farm in the U.K. killed over 400 birds earlier this month. (peta.org)
  • Jim Hightower says, "Trump Dishes Up 'Chicken A La Avian Leukosis. (issuesandalibis.org)
  • The N-terminal amino acid of an avian leukosis group-specific antigen from avian myeloblastosis virus. (microbiologyresearch.org)
  • The radioimmunoassay of the group-specific antigen seems to be well suited to complement the COFAL (complement fixation avian leukosis) and RIF (resistance inducing factor) tests in the detection of leukosis virus in infected material. (microbiologyresearch.org)
  • Appropriate in vivo expression of a muscle-specific promoter by using avian retroviral vectors for gene transfer [corrected]. (org.ua)
  • [18] Cosset FL, Legras C, Thomas JL, Molina RM, Chebloune Y, Faure C, Nigon VM, Verdier G. Improvement of avian leukosis virus (ALV)-based retrovirus vectors by using different cis-acting sequences from ALVs. (org.ua)
  • [19] Benchaibi M, Mallet F, Thoraval P, Savatier P, Xiao JH, Verdier G, Samarut J, Nigon V. Avian retroviral vectors derived from avian defective leukemia virus: role of the translational context of the inserted gene on efficiency of the vectors. (org.ua)
  • Parthenogenesis is the spontaneous development of an embryo from an avian egg without going through the usual process of fertilization 7 , 8 . (scialert.net)
  • Characterization of a 105,000 molecular weight gag-related phosphoprotein from cells transformed by the defective avian sarcoma virus PRCII. (wikidata.org)
  • Avian leukosis is a very rare virus that can form lesions in the internal organs of a bird, such as the liver or spleen. (chickencheck.in)
  • Current regulations require poultry with avian leukosis lesions to be condemned. (usfoodimports.com)
  • In addition to piRNAs that protect the germ-line genome from transposon activation, mammals and avian produce a distinct and abundant set of non-repetitive piRNA sequences whose function is unknown. (rochester.edu)
  • [4] Aronoff R, Hajjar AM, Linial ML. Avian retroviral RNA encapsidation: reexamination of functional 5' RNA sequences and the role of nucleocapsid Cys-His motifs. (org.ua)
  • However, the movement was unsuccessful in maintaining leukosis-free flocks. (wikipedia.org)
  • The avian leukosis virus can lead to severe diseases and severe growth and laying depression in poultry," said Schusser. (feedstuffs.com)
  • RNA species obtained from clonal lines of avian sarcoma and from avian leukosis virus. (wikidata.org)
  • Genetic structure, transforming sequence, and gene product of avian sarcoma virus UR1. (wikidata.org)
  • Avian leukosis virus have been divided into 10 envelope subgroups, A through J, based on host range, receptor interference patterns, and neutralization by antibodies. (geneticpcr.com)
  • [6] Katz RA, Terry RW, Skalka AM. A conserved cis-acting sequence in the 5' leader of avian sarcoma virus RNA is required for packaging. (org.ua)
  • Identification of a sequence likely to be required for avian retroviral packaging. (org.ua)
  • Detection of a protein of avian leukoviruses in uninfected chick cells by RIA. (microbiologyresearch.org)
  • Tyrosine-specific protein kinase activity associated with p105 of avian sarcoma virus PRCII. (wikidata.org)
  • [7] Knight JB, Si ZH, Stoltzfus CM. A base-paired structure in the avian sarcoma virus 5' leader is required for efficient encapsidation of RNA. (org.ua)