What is the genome structure for varicella zoster virus?
Structure of the VZV genome. The genome consists of 124,884 bp of DNA arranged into unique long (UL), unique short (US), terminal repeat long and short (TRL and TRS), and internal repeat long and short (IRL and IRS) regions. of G+C nucleotides in the repeat region is thought to be related to its more recent evolution.
Is the varicella zoster virus an enveloped virus?
Varicella-zoster virus (VZV) is an enveloped double-stranded DNA virus belonging to the family Herpesviridae [70]. VZV is also called human herpesvirus type 3.
Is varicella zoster virus DNA or RNA?
DNA virusVZV is a DNA virus and is a member of the herpesvirus group. Like other herpesviruses, VZV persists in the body as a latent infection after the primary (first) infection; VZV persists in sensory nerve ganglia. Primary infection with VZV results in varicella.
Is varicella zoster virus enveloped or non enveloped How does a virus obtain its envelope?
Similar to all herpesviruses, VZV has a lipid-rich envelope, which is acquired from cellular membranes and into which viral glycoproteins are inserted.
What is the size of varicella-zoster virus?
The Varicella-Zoster virus has a diameter of 150-200 nm and contains a linear, double stranded DNA (125 kbp) genome, enclosed within an icosahedral capsid, surrounded by a phospholipid envelope.
Where does varicella-zoster virus come from?
Abstract. Varicella zoster virus (VZV) is the causative agent of chickenpox and shingles. The geographic distribution of VZV clades was taken as evidence that VZV migrated out of Africa with human populations. We show that extant VZV strains most likely originated in Europe and not in Africa.
Is varicella an RNA virus?
Described in a recent paper in Nature Communications, researchers discovered there is an RNA transcript in the varicella zoster virus (VZV), that continues to remain active after a person has recovered from chickenpox.
What is the genetic material of chickenpox virus?
The genome of VZV consists of a linear double-stranded DNA molecule and is approximately 125 kbp in size, which contains more than 70 annotated open reading frames (ORFs) (Tyler et al., 2007).
What cells does varicella zoster affect?
Varicella-zoster virus (VZV) is a human alphaherpesvirus that infects >90% of people worldwide. ... During primary infection, VZV replicates in respiratory epithelial cells and is transferred to T cells within the tonsillar lymphoid tissue [10, 11], either directly or via virus-infected dendritic cells (DCs) [12].More items...•
Which viruses are DNA viruses?
DNA viruses comprise important pathogens such as herpesviruses, smallpox viruses, adenoviruses, and papillomaviruses, among many others.
Is measles a DNA or RNA virus?
The measles virus is a single-stranded RNA virus of the genus Morbillivirus and the family Paramyxoviridae. The virus is related to several viruses that infect animals, including the Canine Distemper Virus.
Are there any DNA viruses?
DNA viruses are divided into three major categories: double-stranded (ds) DNA viruses (e.g., poxviruses), single-stranded (ss) DNA viruses (e.g., parvoviruses), and pararetroviruses (e.g., hepadnaviruses). Large DNA viruses (> 10 kb) have dsDNA, whereas small DNA viruses typically have circular ss or dsDNA.
Is mumps RNA or DNA?
Mumps virus is a paramyxovirus in the same group as parainfluenza and Newcastle disease viruses, which produce antibodies that cross-react with mumps virus. The virus has a single-stranded RNA genome. The virus can be isolated or propagated in cultures of various human and monkey tissues and in embryonated eggs.
Overview
Varicella-zoster virus (VZV), also known as human herpesvirus 3 (HHV-3, HHV3) or Human alphaherpesvirus 3 (taxonomically), is one of nine known herpes viruses that can infect humans. It causes chickenpox (varicella) commonly affecting children and young adults, and shingles (herpes zoster) in adults but rarely in children. VZV infections are species-specific to humans, but the virus …
Epidemiology
Primary varicella zoster virus infection results in chickenpox (varicella), which may result in complications including encephalitis, pneumonia (either direct viral pneumonia or secondary bacterial pneumonia), or bronchitis (either viral bronchitis or secondary bacterial bronchitis). Even when clinical symptoms of chickenpox have resolved, VZV remains dormant in the nervous system of the infected person (virus latency), in the trigeminal and dorsal root ganglia. VZV enters through the r…
Morphology
VZV is closely related to the herpes simplex viruses (HSV), sharing much genome homology. The known envelope glycoproteins (gB, gC, gE, gH, gI, gK, gL) correspond with those in HSV; however, there is no equivalent of HSV gD. VZV also fails to produce the LAT (latency-associated transcripts) that play an important role in establishing HSV latency (herpes simplex virus). VZV virions are spherical and 180–200 nm in diameter. Their lipid envelope encloses the 100 nm nucl…
Genomes
The genome was first sequenced in 1986. It is a linear duplex DNA molecule, a laboratory strain has 124,884 base pairs. The genome has 2 predominant isomers, depending on the orientation of the S segment, P (prototype) and IS (inverted S) which are present with equal frequency for a total frequency of 90–95%. The L segment can also be inverted resulting in a total of four linear isomers (IL and ILS). This is distinct from HSV's equiprobable distribution, and the discriminator…
Evolution
Commonality with HSV1 and HSV2 indicates a common ancestor; five genes (out of about 70) do not have corresponding HSV genes. Relation with other human herpes viruses is less strong, but many homologues and conserved gene blocks are still found.
There are at least five clades of this virus. Clades 1 and 3 include European/North American strains; clade 2 are Asian strains, especially from Japan; and clade 5 appears to be based in India. …
Treatment
Within the human body it can be treated by a number of drugs and therapeutic agents including acyclovir for the chicken pox, famciclovir, valaciclovir for the shingles, zoster-immune globulin (ZIG), and vidarabine. Acyclovir is frequently used as the drug of choice in primary VZV infections, and beginning its administration early can significantly shorten the duration of any symptoms. However, reaching an effective serum concentration of acyclovir typically requires intravenous a…
Vaccination
A live attenuated VZV Oka/Merck strain vaccine is available and is marketed in the United States under the trade name Varivax. It was developed by Merck, Sharp & Dohme in the 1980s from the Oka strain virus isolated and attenuated by Michiaki Takahashi and colleagues in the 1970s. It was submitted to the US Food and Drug Administration for approval in 1990 and was approved in 1995. Since then, it has been added to the recommended vaccination schedules for children in Australia, …
History
Chickenpox-like rashes were recognized and described by ancient civilizations; the relationship between zoster and chickenpox was not realized until 1888. In 1943, the similarity between virus particles isolated from the lesions of zoster and those from chickenpox was noted. In 1974 the first chickenpox vaccine was introduced. Etymology: "A member of the family Herpesviridae, varicella zoster virus (VZV) is named for the 2 main diseases (chickenpox and herpes zoster [shingles]) i…