Adenoviruses (members of the family Adenoviridae ) are medium-sized (90–100 nm ), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953.
79-600: They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of illnesses , from mild respiratory infections in young children (known as the common cold ) to life-threatening multi-organ disease in people with a weakened immune system . This family contains the following genera : In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (Human adenovirus A to G): Different types/serotypes are associated with different conditions: All these types are called Human mastadenovirus A–G by
158-662: A Science article reported that China had approved CanSino 's Ebola vaccine based on an Ad5 vector. It was tested in Sierra Leone , which had high HIV prevalence , making it more likely for such problems to be detected. CanSino's CEO said "we haven't seen anything with the Ebola vaccine" and speculated that HIV susceptibility might be limited to Ad5 vaccines which produced HIV proteins. In research reported in The Lancet in May,
237-549: A backbone or spine, consisting of vertebrae and intervertebral discs . The vertebrae are irregular bones , and the intervertebral discs are of fibrocartilage . The vertebral column surrounds and protects the spinal cord . The other feature unique to vertebrates is the presence of a cranium , or skull. The vertebrates make up the subphylum Vertebrata with some 65,000 species in the phylum Chordata . The vertebrates include mammals , birds , amphibians , and various classes of reptiles and fish . Classes of fish include
316-427: A jaw , hyoid and/or the middle ear ossicles . An iodine-concentrating organ called the endostyle , which functions as a filter feeding organ in aquatic animals has evolved into the thyroid in most vertebrates. Vertebrates vary in body length ranging from the frog species Brachycephalus pulex , a Brazilian flea toad, with a minimum adult snout–vent length of 6.45 millimetres (0.254 in) to
395-417: A central nervous system arising from a single nerve cord dorsal to the gut tube , headed by a series of (typically paired) brain vesicles, is unique to vertebrates. This is in stark contrast to invertebrates with well-developed central nervous systems such as arthropods and cephalopods , which have an often ladder-like ventral nerve cord made of paired segmental ganglia on the opposite ( ventral ) side of
474-425: A decade, was shipped to basic training sites on 18 October 2011. Prevention of adenovirus, as well as other respiratory illnesses, involves frequent hand washing for more than 20 seconds, avoiding touching the eyes, face, and nose with unwashed hands, and avoiding close contact with people with symptomatic adenovirus infection. Those with symptomatic adenovirus infection are additionally advised to cough or sneeze into
553-525: A hollow neural tube ) running along the dorsal aspect of the notochord . Of particular importance and unique to vertebrates is the presence of neural crest cells, which are progenitor cells critical to coordinating the functions of cellular components. Neural crest cells migrate through the body from the dorsal nerve cord during development, initiate the formation of neuronal ganglia and various special sense organs. The peripheral nervous system forms when neural crest cells branch out laterally from
632-451: A linear dsDNA genome and are able to replicate in the nucleus of vertebrate cells using the host's replication machinery. Entry of adenoviruses into the host cell involves two sets of interactions between the virus and the host cell. Most of the action occurs at the vertices. Entry into the host cell is initiated by the knob domain of the fiber protein binding to the cell receptor. The two currently established receptors are: CD46 for
711-422: A major effort is made to limit hepatotoxicity and prevent multiple organ failure. Adenovirus dodecahedron can qualify as a potent delivery platform for foreign antigens to human myeloid dendritic cells (MDC), and that it is efficiently presented by MDC to M1-specific CD8+ T lymphocytes. A safety issue with adenoviruses is that they can cause an immune response with a related inflammatory response as occurred in
790-432: A potentially fatal disease involving vasculitis and hepatitis . Type 1 infection can also cause respiratory and eye infections. CAdV-1 also affects foxes ( Vulpes vulpes and Vulpes lagopus ) and may cause hepatitis and encephalitis. Canine adenovirus 2 (CAdV-2) is one of the potential causes of kennel cough . Core vaccines for dogs include attenuated live CAdV-2, which produces immunity to CAdV-1 and CAdV-2. CAdV-1
869-589: A protein related to ubiquitin carboxyl-terminal hydrolase are exclusively shared by all vertebrates and reliably distinguish them from all other animals. A specific relationship between vertebrates and tunicates is strongly supported by two CSIs found in the proteins Rrp44 (associated with the exosome complex ) and serine palmitoyltransferase . These are exclusively shared by species from these two subphyla, but not cephalochordates . This indicates hat vertebrates are more closely related to tunicates than cephalochordates. The "Notochordata hypothesis" suggested that
SECTION 10
#1732798249981948-606: A series of crescentic openings from the pharynx to the outside. Each gill is supported by a cartilaginous or bony gill arch , which develop embryonically from pharyngeal arches . Bony fish have three pairs of gill arches, cartilaginous fish have five to seven pairs, while the primitive jawless fish have seven pairs. The ancestral vertebrates likely had more arches than seven, as some of their chordate relatives have more than 50 pairs of gill opens, although most, if not all, of these openings are actually involved in filter feeding rather than respiration . In jawed vertebrates ,
1027-416: A vehicle to administer targeted therapy , in the form of recombinant DNA or protein. This therapy has been found especially useful in treating monogenic disease (e.g. cystic fibrosis , X-linked SCID , alpha1-antitrypsin deficiency) and cancer. In China, oncolytic adenovirus is an approved cancer treatment. Specific modifications on fiber proteins are used to target Adenovirus to certain cell types;
1106-559: A wide range of responses, from no symptoms at all to the severe infections typical of Adenovirus serotype 14 . Bat adenovirus TJM (Bt-AdV-TJM) is a novel species of the Mastadenovirus genus isolated from Myotis and Scotophilus kuhlii in China. It is most closely related to the tree shrew and canine AdVs. Two types of canine adenoviruses are well known, type 1 and 2. Type 1 (CAdV-1) causes infectious canine hepatitis ,
1185-440: Is found in invertebrate chordates such as lancelets (a sister subphylum known as the cephalochordates ), though it lacks eyes and other complex special sense organs comparable to those of vertebrates. Other chordates do not show any trends towards cephalization. The rostral end of the neural tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles :
1264-561: Is found to be present, it may not be the cause of any symptoms. Some immunocompromised individuals can shed the virus for weeks and show no symptoms. Most infections with adenovirus result in infections of the upper respiratory tract. Adenovirus infections often present as conjunctivitis , tonsillitis (which may look exactly like strep throat and cannot be distinguished from strep except by throat culture), an ear infection , or croup . Adenoviruses types 40 and 41 can also cause gastroenteritis . A combination of conjunctivitis and tonsillitis
1343-416: Is innovative because an Ad26 based vaccine is used on the first day and an Ad5 vaccine is used on day 21. Another one is ChAd-SARS-CoV-2-S ; the vaccine reportedly prevented mice that were genetically modified to have human ACE2 (hACE2) receptors, presumably receptors that allow virus-entry into the cells, from being infected with SARS-CoV-2. Possible issues with using Adenovirus as vaccine vectors include:
1422-510: Is largely directed at the symptoms (such as acetaminophen for fever). The antiviral drug cidofovir has helped certain of those patients who had severe cases of illness; the number helped and to what degree, and the particular complications or symptoms it helped with, and when and where this happened, were not given in the source. A doctor may give antibiotic eyedrops for conjunctivitis, while awaiting results of bacterial cultures, and to help prevent secondary bacterial infections. Currently, there
1501-500: Is no adenovirus vaccine available to the general public, but a vaccine is available for the United States military for Types 4 and 7. Adenoviruses have long been a popular viral vector for gene therapy due to their ability to affect both replicating and non-replicating cells, accommodate large transgenes , and code for proteins without integrating genetic material into the host cell genome. More specifically, they are used as
1580-412: Is particularly common with adenovirus infections. Some children (especially the youngest) can develop adenovirus bronchiolitis or pneumonia , both of which can be severe. In babies, adenoviruses can also cause coughing fits that look almost exactly like whooping cough . Adenoviruses can also cause viral meningitis or encephalitis . Rarely, adenovirus can cause hemorrhagic cystitis (inflammation of
1659-463: Is separated by the DNA replication process into two phases: an early and a late phase. In both phases, a primary transcript that is alternatively spliced to generate monocistronic mRNAs compatible with the host's ribosome is generated, allowing for the products to be translated . The early genes are responsible for expressing mainly non-structural, regulatory proteins . The goal of these proteins
SECTION 20
#17327982499811738-495: Is significantly larger than other viruses in its Baltimore group , it is still a very simple virus and is heavily reliant on the host cell for survival and replication. The genes of adenoviruses can generally be divided into well-conserved sets of transcription units with six early transcription units (E1A, E1B, E2A, E2B, E3 and E4) and one late transcription unit ranging from L1-L5. In addition, adenoviruses also contain two intermediate transcription units named XI and IVa2. To increase
1817-462: Is subsequently released, which can enter the nucleus via the nuclear pore . After this the DNA associates with histone molecules already present in the nucleus, which allows it to interact with the host cell transcription machinery. Then, viral gene expression can occur, without integrating the viral genome into host cell chromosomes, and new virus particles can be generated. The adenovirus life cycle
1896-658: Is threefold: to alter the expression of host proteins that are necessary for DNA synthesis ; to activate other virus genes (such as the virus-encoded DNA polymerase ); and to avoid premature death of the infected cell by the host-immune defenses (blockage of apoptosis , blockage of interferon activity, and blockage of MHC class I translocation and expression). Some adenoviruses under specialized conditions can transform cells using their early gene products. E1A (binds Retinoblastoma tumor suppressor protein ) has been found to immortalize primary cells in vitro allowing E1B (binds p53 tumor suppressor) to assist and stably transform
1975-459: The host cell via the receptor on its surface. In 2010, the structure of the human adenovirus was solved at the atomic level, making it the largest high-resolution model ever. The virus is composed of around 1 million amino acid residues and weighs around 150 MDa . The adenovirus genome is linear, non-segmented double-stranded (ds) DNA that is between 26 and 48 k bp . This allows the virus to theoretically carry 22 to 40 genes . Although this
2054-635: The Cephalochordata is the sister taxon to Craniata (Vertebrata). This group, called the Notochordata, was placed as sister group to the Tunicata (Urochordata). Studies since 2006 analyzing large sequencing datasets however strongly support Olfactores (tunicates + vertebrates) as a clade, and hence the placement of Cephalochordata as sister-group to Olfactores (known as the " Olfactores hypothesis "). The following cladogram summarizes
2133-559: The Chengjiang biota and lived about 518 million years ago. These include Haikouichthys , Myllokunmingia , Zhongjianichthys , and probably Haikouella . Unlike the other fauna that dominated the Cambrian, these groups had the basic vertebrate body plan: a notochord, rudimentary vertebrae, and a well-defined head and tail. All of these early vertebrates lacked jaws in the common sense and relied on filter feeding close to
2212-465: The ICTV , because all are members of the genus Mastadenovirus . Adenoviruses are medium-sized (90–100 nm). The virions are composed of one linear piece of double-stranded DNA inside an icosahedral capsid . 240 hexon proteins make up the bulk of the capsid, while twelve penton bases cap the icosahedron's corners. The penton bases are associated with protruding fibers that aid in attachment to
2291-474: The Izu–Ogasawara Trench at a depth of 8,336 metres (27,349 feet). Many fish varieties are the main predators in most of the world's freshwater and marine water bodies . The rest of the vertebrate species are tetrapods, a single lineage that includes amphibians (with roughly 7,000 species); mammals (with approximately 5,500 species); and reptiles and birds (with about 20,000 species divided evenly between
2370-633: The Jurassic . The Cenozoic world saw great diversification of bony fishes, amphibians, reptiles, birds and mammals. Over half of all living vertebrate species (about 32,000 species) are fish (non-tetrapod craniates), a diverse set of lineages that inhabit all the world's aquatic ecosystems, from the Tibetan stone loach ( Triplophysa stolickai ) in western Tibetan hot springs near Longmu Lake at an elevation of 5,200 metres (17,100 feet) to an unknown species of snailfish (genus Pseudoliparis ) in
2449-464: The Latin vertebratus ("jointed"), from vertebra meaning "joint", in turn from Latin vertere to turn. All vertebrates are built along the basic chordate body plan of five synapomorphies . These are a rigid axial skeleton that includes a vertebral column developed around an elastic notochord . The notochord becomes the intervertebral discs , and runs dorsally to the gut tube along
Adenoviridae - Misplaced Pages Continue
2528-574: The Placodermi and the Acanthodii , both considered paraphyletic . Other ways of classifying the vertebrates have been devised, particularly with emphasis on the phylogeny of early amphibians and reptiles. An example based on Janvier (1981, 1997), Shu et al. (2003), and Benton (2004) is given here († = extinct ): While this traditional classification is orderly, most of the groups are paraphyletic , i.e. do not contain all descendants of
2607-1020: The Tree of Life Web Project and Delsuc et al., and complemented (based on, and ). A dagger (†) denotes an extinct clade , whereas all other clades have living descendants . Hyperoartia ( lampreys ) [REDACTED] Myxini ( hagfish ) [REDACTED] † Euconodonta [REDACTED] † Myllokunmingiida [REDACTED] † Pteraspidomorphi [REDACTED] † Thelodonti [REDACTED] † Anaspida [REDACTED] † Galeaspida [REDACTED] † Pituriaspida [REDACTED] † Osteostraci [REDACTED] † Antiarchi [REDACTED] † Petalichthyida [REDACTED] † Arthrodira [REDACTED] † Ptyctodontida [REDACTED] † Entelognathus [REDACTED] Adenovirus genome Adenovirus genomes are linear, non-segmented double-stranded (ds) DNA molecules that are typically 26-46 Kbp long, containing 23-46 protein-coding genes . The example used for
2686-399: The blue whale , at up to 33 m (108 ft). With only one exception, the defining characteristic of all vertebrates is the vertebral column , in which the embryonic notochord found in all chordates is replaced by a segmented series of mineralized elements called vertebrae separated by fibrocartilaginous intervertebral discs , which are embryonic and evolutionary remnants of
2765-565: The genetics of organisms. Phylogenetic classification is based solely on phylogeny . Evolutionary systematics gives an overview; phylogenetic systematics gives detail. The two systems are thus complementary rather than opposed. Conventional classification has extant vertebrates grouped into seven classes based on traditional interpretations of gross anatomical and physiological traits. The commonly held classification lists three classes of fish and four of tetrapods . In addition to these, there are two classes of extinct armoured fishes,
2844-410: The prosencephalon ( forebrain ), mesencephalon ( midbrain ) and rhombencephalon ( hindbrain ), which are further differentiated in the various vertebrate groups. Two laterally placed retinas and optical nerves form around outgrowths from the midbrain, except in hagfish which may have secondarily lost the structures. The forebrain is more well-developed in most tetrapods and subdivided into
2923-432: The telencephalon and diencephalon , while the midbrain dominates in fish and some salamanders . In vertebrates with paired appendages, especially tetrapods, a pair of secondary enlargements of the hindbrain become the cerebella , which modulate complex motor coordinations . The brain vesicles are usually bilaterally symmetrical , giving rise to the paired cerebral hemispheres in mammals . The resultant anatomy of
3002-643: The 'vector' to transport the surface protein gene of SARS-CoV-2". The goal is to genetically express the spike glycoprotein of severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ). A replication-deficient chimpanzee adenovirus vaccine vector (ChAdOx1) is used by the Oxford–AstraZeneca COVID-19 vaccine that has been approved for use. The Janssen COVID-19 vaccine uses modified recombinant adenovirus type-26 (Ad26). Recombinant adenovirus type-5 (Ad5) are being used by Ad5-nCoV , ImmunityBio and UQ-CSL V451 . The Gam-COVID-Vac (aka Sputnik-V) product
3081-455: The adenovirus genome can occur. A terminal protein that is covalently bound to the 5' end of the adenovirus genome acts as a primer for replication. The viral DNA polymerase then uses a strand displacement mechanism, as opposed to the conventional Okazaki fragments used in mammalian DNA replication, to replicate the genome. The late phase of the adenovirus lifecycle is focused on producing sufficient quantities of structural protein to pack all
3160-422: The adenovirus. This co-receptor molecule is αV integrin . Binding to αV integrin results in endocytosis of the virus particle via clathrin-coated pits. Attachment to αV integrin stimulates cell signaling and thus induces actin polymerization, which facilitates clathrin-mediated endocytosis, and results in virion's entry into the host cell within an endosome . Once the virus has successfully gained entry into
3239-546: The arm or elbow instead of the hand, to avoid sharing cups and eating utensils, and to refrain from kissing others. Chlorination of swimming pools can prevent outbreaks of conjunctivitis caused by adenovirus. Diagnosis is from symptoms and history. Tests are only necessary in very serious cases. Tests include blood tests, eyes, nose or throat swabs, stool sample tests, and chest x-rays. In the laboratory, adenovirus can be identified with antigen detection, polymerase chain reaction (PCR), virus isolation and serology. Even if adenovirus
Adenoviridae - Misplaced Pages Continue
3318-418: The axial endoskeleton (enclosed by protective skeletal extensions known as neural arches ), with a fore-end enlargement that is contained within a distinct skeletonized braincase (hence the alternative name for vertebrates, the craniates ). All vertebrate embryos develop transient pharyngeal arches , which in fish develop into the branchial arches that support the gills . Other vertebrate features are
3397-470: The binding of protein VI to the endsomal membrane leading to a severe membrane curvature that ultimately disrupts the endosome. These changes, as well as the toxic nature of the pentons, destroy the endosome, resulting in the movement of the virion into the cytoplasm. With the help of cellular microtubules , the virus is transported to the nuclear pore complex, whereby the adenovirus particle disassembles. Viral DNA
3476-476: The body and water. Adenoviruses are spread primarily via respiratory droplets, however they can also be spread by fecal routes and via aerosols ( airborne transmission ). Research into the molecular mechanisms underlying adenoviral transmission provide empirical evidence in support of the hypothesis that coxsackievirus/adenovirus receptors (CARs) are needed to transport adenoviruses into certain naive/progenitor cell types. Humans infected with adenoviruses display
3555-427: The brain (which itself is a fused cluster of segmental ganglia from the rostral metameres ). Molecular markers known as conserved signature indels (CSIs) in protein sequences have been identified and provide distinguishing criteria for the vertebrate subphylum. Specifically, 5 CSIs in the following proteins: protein synthesis elongation factor-2 , eukaryotic translation initiation factor 3 , adenosine kinase and
3634-419: The cells. Nevertheless, they are reliant upon each other to successfully transform the host cell and form tumors . E1A is mostly intrinsically disordered protein and contains CR3 domain which is critical for transcriptional activation. DNA replication separates the early and late phases. Once the early genes have liberated adequate virus proteins, replication machinery, and replication substrates, replication of
3713-409: The class's common ancestor. For instance, descendants of the first reptiles include modern reptiles, mammals and birds; the agnathans have given rise to the jawed vertebrates ; the bony fishes have given rise to the land vertebrates ; the traditional " amphibians " have given rise to the reptiles (traditionally including the synapsids or mammal-like "reptiles"), which in turn have given rise to
3792-812: The company's researchers acknowledged the possibility, called it "controversial" and said they would watch for it in the company's COVID-19 vaccine candidate's trials. It is not known to what extent LGBT discrimination in Sierra Leone could have contributed to masking a possible causal link in the Ebola vaccine trial; while the Step trial enrolled mainly homosexual and bisexual men, the Phambili trial enrolled mainly heterosexual men and women and still found an apparent connection. Vertebrate Ossea Batsch, 1788 Vertebrates ( / ˈ v ɜːr t ə b r ɪ t s , - ˌ b r eɪ t s / ) are animals with
3871-663: The death of Jesse Gelsinger in 1999. To address this risk, the genome of the viral genes have been modified to remove some viral genes. One such modification is the gutless vector that removes almost all the viral genome. Adenovirus has been used for delivery of CRISPR/Cas9 gene editing systems, but high immune reactivity to viral infection has posed challenges in use for patients. Modified ( recombinant ) adenovirus vectors, including replication incompetent types, can deliver DNA coding for specific antigens . Adenovirus have been used to produce viral vector COVID-19 vaccines . "In four candidate COVID-19 vaccines... Ad5... serves as
3950-556: The demise of virtually all jawless fishes save for lampreys and hagfishes, as well as the Placodermi , a group of armoured fish that dominated the entirety of that period since the late Silurian as well as the eurypterids , dominant animals of the preceding Silurian , and the anomalocarids . By the middle of the Devonian, several droughts, anoxic events and oceanic competition led a lineage of sarcopterygii to leave water, eventually establishing themselves as terrestrial tetrapods in
4029-408: The dorsal nerve cord and migrate together with the mesodermal somites to innervate the various different structures that develop in the body. The vertebrates are the only chordate group with neural cephalization , and their neural functions are centralized towards a series of enlarged clusters in the head , which give rise to a brain . A slight swelling of the anterior end of the nerve cord
SECTION 50
#17327982499814108-483: The first gill arch pair evolved into the jointed jaws and form an additional oral cavity ahead of the pharynx . Research also suggests that the sixth branchial arch contributed to the formation of the vertebrate shoulder, which separated the head as a distinct part of the body. In amphibians and some primitive bony fishes, the larvae bear external gills , branching off from the gill arches. These are reduced in adulthood, their respiratory function taken over by
4187-569: The following description is Human adenovirus E, a mastadenovirus with a 36 Kbp genome containing 38 protein-coding genes. While the precise number and identity of genes varies among adenoviruses, the basic principles of genome organization and the functions of most of the genes described in this article are shared among all adenoviruses. The 38 genes in the Human adenovirus E genome are organized in 17 transcription units, each containing 1-8 coding sequences. Alternative splicing during processing of
4266-450: The general population or on people with weakened immune systems. In the past, US military recruits were vaccinated against two serotypes of adenovirus, with a corresponding decrease in illnesses caused by those serotypes. That vaccine is no longer manufactured. The U.S. Army Medical Research and Materiel Command announced on 31 October 2011 that a new adenovirus vaccine, which replaces the older version that has been out of production for over
4345-414: The genetic material produced by DNA replication. Once the viral components have successfully been replicated, the virus is assembled into its protein shells and released from the cell as a result of virally induced cell lysis . Adenovirus is capable of multiplicity reactivation (MR) (Yamamoto and Shimojo, 1971). MR is the process by which two, or more, virus genomes containing lethal damage interact within
4424-421: The gill arches form during fetal development , and form the basis of essential structures such as jaws , the thyroid gland , the larynx , the columella (corresponding to the stapes in mammals ) and, in mammals, the malleus and incus . The central nervous system of vertebrates is based on the embryonic dorsal nerve cord (which then flattens into a neural plate before folding and fusing over into
4503-431: The group B human adenovirus serotypes and the coxsackievirus/adenovirus receptor (CAR) for all other serotypes. There are some reports suggesting MHC molecules and sialic acid residues functioning in this capacity as well. This is followed by a secondary interaction, where a motif in the penton base protein (see capsomere ) interacts with an integrin molecule. It is the co-receptor interaction that stimulates entry of
4582-400: The gut tube, with a split brain stem circumventing the foregut around each side to form a brain on the dorsal side of the mouth . The higher functions of the vertebrate CNS are highly centralized towards the brain (particularly the forebrain), while the invertebrate CNS is significantly more decentralized with the segmental ganglia having substantial neural autonomy independent of
4661-403: The host cell, the endosome acidifies, which alters virus topology by causing capsid components to disband. The capsid is destabilized and protein VI, which is one of the capsid constituents (see Adenovirus genome ) is released from it. Protein VI contains an N-terminal amphiphatic alpha-helix, a helical domain that exhibits both hydrophobic and hydrophilic properties. This amphipathic helix enables
4740-432: The host response to infection. The L1-L5 transcription units are transcribed later in the viral reproductive cycle, and code mostly for proteins that make up components of the viral capsid or are involved in assembly of the capsid. The L1-L5 transcription units are all regulated by the same promoter region and share the same transcription start site. As a result, transcription of all five late transcription units begins at
4819-462: The human body develops immunity to the vector itself, making subsequent booster shots difficult or impossible. In some cases, people have pre-existing immunity to Adenoviruses, making vector delivery ineffective. The use of Ad5 vaccines for COVID-19 worried researchers who had experience with two failed trials of an Ad5 vaccine, Phambili and STEP, due to the increased risk for uncircumcised male patients of contracting HIV-1 via unprotected anal sex. At
SECTION 60
#17327982499814898-559: The infected cell to form a viable virus genome. Such MR was demonstrated for adenovirus 12 after virions were irradiated with UV light and allowed to undergo multiple infection of host cells. In a review, numerous examples of MR in different viruses were described, and it was suggested that MR is a common form of sexual interaction that provides the survival advantage of recombinational repair of genome damages. Adenoviruses are unusually stable to chemical or physical agents and adverse pH conditions, allowing for prolonged survival outside of
4977-443: The internal gills proper in fishes and by cutaneous respiration in most amphibians. While some amphibians such as axolotl retain the external gills into adulthood, the complex internal gill system as seen in fish apparently being irrevocably lost very early in the evolution of tetrapods , who evolved lungs (which are homologous to swim bladders ) to breathe air. While the more specialized terrestrial vertebrates lack gills,
5056-407: The jawless Agnatha , and the jawed Gnathostomata . The jawed fish include both the cartilaginous fish and the bony fish . Bony fish include the lobe-finned fish , which gave rise to the tetrapods , the animals with four limbs. Vertebrates make up less than five percent of all described animal species ; the rest are all invertebrates , that lack a backbone. The word 'vertebrate' derives from
5135-432: The length of an animal, hence the common name of backbone. The axial endoskeleton typically continues beyond the anus / cloaca to form an elongated tail . Some vertebrates evolved to become tailless with only a vestigial coccyx . A dorsal nerve cord , which folds and fuses into a hollow neural tube during embryonic development and eventually gives rise to the brain and spinal cord , runs more dorsally to
5214-460: The mammals and birds. Most scientists working with vertebrates use a classification based purely on phylogeny , organized by their known evolutionary history and sometimes disregarding the conventional interpretations of their anatomy and physiology. In phylogenetics , the relationships between animals are illustrated as a hierarchy known as a phylogenetic tree . The cladogram below is based on studies compiled by Philippe Janvier and others for
5293-411: The notochord. Hagfish are the only extant vertebrate whose notochord persists and is not integrated/ replaced by the vertebral column. A few vertebrates have secondarily lost this feature and retain the notochord into adulthood, such as the sturgeon . Most vertebrates are aquatic and carry out gas exchange via gills . The gills are carried right behind the head, bordering the posterior margins of
5372-431: The pre-mRNAs produced by each transcription unit enable multiple different mRNAs to be produced from one transcription unit. The E1A, E1B, E2A, E2B, E3, and E4 transcription units are successively transcribed early in the viral reproductive cycle . The proteins coded for by genes within these transcription units are mostly involved in regulation of viral transcription, in replication of viral DNA, and in suppression of
5451-609: The relationships between the Olfactores (vertebrates and tunicates) and the Cephalochordata. Amphioxiformes (lancelets) [REDACTED] Tunicata /Urochordata ( sea squirts , salps , larvaceans ) [REDACTED] Vertebrata [REDACTED] Vertebrates originated during the Cambrian explosion , which saw a rise in organism diversity. The earliest known vertebrates belongs to
5530-420: The same point in the viral reproductive cycle. Transcription of pre-mRNAs beginning at the late promoter is randomly terminated at one of five termination sites, producing a population of transcripts of five different lengths. The pre-mRNAs of any given length are then alternatively spliced to produce 1-4 different mRNAs coding for a corresponding number of proteins. The names, locations, and properties of
5609-661: The seabed. A vertebrate group of uncertain phylogeny, small eel-like conodonts , are known from microfossils of their paired tooth segments from the late Cambrian to the end of the Triassic. The first jawed vertebrates may have appeared in the late Ordovician (~445 mya) and became common in the Devonian period , often known as the "Age of Fishes". The two groups of bony fishes , the Actinopterygii and Sarcopterygii , evolved and became common. The Devonian also saw
5688-650: The succeeding Carboniferous . Amniotes branched from amphibious tetrapods early in the Carboniferous period. The synapsid amniotes were dominant during the late Paleozoic, the Permian , while diapsid amniotes became dominant during the Mesozoic . In the sea, the teleosts and sharks became dominant. Mesothermic synapsids called cynodonts gave rise to endothermic mammals and diapsids called dinosaurs eventually gave rise to endothermic birds , both in
5767-755: The time, it was concluded that heightened risk of HIV reception may be observed for any Ad5-based vector vaccine. In October 2020, these researchers wrote in The Lancet : "On the basis of these findings, we are concerned that use of an Ad5 vector for immunisation against SARS-CoV-2 could similarly increase the risk of HIV-1 acquisition among men who receive the vaccine." Vaccines using other technologies would not be affected, but Sputnik V , Convidecia and ImmunityBio's hAd5 would. Two studies found that Ad5-specific CD4 T cells are more susceptible to HIV infection than CD4 T cells specific to certain other vectors, such as Cytomegalovirus and Canarypox . By comparison,
5846-402: The two classes). Tetrapods comprise the dominant megafauna of most terrestrial environments and also include many partially or fully aquatic groups (e.g., sea snakes , penguins , cetaceans). There are several ways of classifying animals. Evolutionary systematics relies on anatomy , physiology and evolutionary history, which is determined through similarities in anatomy and, if possible,
5925-776: The urinary bladder—a form of urinary tract infection —with blood in the urine). Most people recover from adenovirus infections by themselves, but people with immunodeficiency sometimes die of adenovirus infections, and—rarely—even previously healthy people can die of these infections. This may be because sometimes adenoviral infection can lead to cardiac disorders. For example, in one study, some cardiac samples of patients with dilated cardiomyopathy were positive for presence of adenovirus type 8. Adenoviruses are often transmitted by expectoration (e.g. aerosols), but they can also be transmitted by contact with an infected person, or by virus particles left on objects such as towels and faucet handles. Some people with adenovirus gastroenteritis may shed
6004-442: The viral gene economy, adenoviruses accommodate genes on both strands of its dsDNA meaning that most of its genome is utilized for coding proteins. An interesting feature of this viral genome is that it has a terminal 55 kDa protein associated with each of the 5' ends of the linear dsDNA. These are used as primers in viral replication and ensure that the ends of the virus' linear genome are adequately replicated. Adenoviruses possess
6083-431: The virus in their stools for months after getting over the symptoms. The virus can be passed through water in swimming pools that are not sufficiently chlorinated. As with many other illnesses, good handwashing practice is one way to inhibit the person-to-person transmission of adenoviruses. Heat and bleach will kill adenoviruses on objects. There are no proven antiviral drugs to treat adenoviral infections, so treatment
6162-1232: Was initially used in a vaccine for dogs, but corneal edema was a common complication. Squirrel adenovirus (SqAdV) is reported to cause enteritis in red squirrels in Europe, while gray squirrels seem to be resistant. SqAdV is most closely related to the adenovirus of guinea pigs (GpAdV). Adenovirus in reptiles is poorly understood, but research is currently in progress. Adenoviruses are also known to cause respiratory infections in horses , cattle , pigs , sheep , and goats . Equine adenovirus 1 can also cause fatal disease in immunocompromised Arabian foals , involving pneumonia and destruction of pancreatic and salivary gland tissue. Tupaia adenovirus (TAV) (tree shrew adenovirus 1) has been isolated from tree shrews. Otarine adenovirus 1 has been isolated from sea lions ( Zalophus californianus ). The fowl adenoviruses are associated with many disease conditions in domestic fowl like inclusion body hepatitis , hydropericardium syndrome , Egg drop syndrome , Quail bronchitis , Gizzard erosions and many respiratory conditions. They have also been isolated from wild black kites (Milvus migrans). Titi monkey adenovirus
6241-426: Was isolated from a colony of monkeys. Currently there is a vaccine for adenovirus type 4 and 7 for US military personnel only. US military personnel are the recipients of this vaccine because they may be at a higher risk of infection. The vaccine contains a live virus, which may be shed in stool and lead to transmission. The vaccine is not approved for use outside of the military, as it has not been tested in studied in
#980019