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Orthopoxvirus particles. A DNA virus is a virus that has a genome made of deoxyribonucleic acid (DNA) that is replicated by a DNA polymerase.They can be divided between those that have two strands of DNA in their genome, called double-stranded DNA (dsDNA) viruses, and those that have one strand of DNA in their genome, called single-stranded DNA (ssDNA) viruses. dsDNA viruses primarily belong ...
A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. [ 1 ] Examples include the common cold , gastroenteritis , COVID-19 , the flu , and rabies .
Viruses with a DNA genome, except for the DNA reverse transcribing viruses, are members of three of the four recognized viral realms: Duplodnaviria, Monodnaviria, and Varidnaviria. But the incertae sedis order Ligamenvirales , and many other incertae sedis families and genera, are also used to classify DNA viruses.
The genes of viruses are made from DNA (deoxyribonucleic acid) and, in many viruses, RNA (ribonucleic acid). The biological information contained in an organism is encoded in its DNA or RNA. Most organisms use DNA, but many viruses have RNA as their genetic material. The DNA or RNA of viruses consists of either a single strand or a double helix ...
The prototypic members of the realm are often called CRESS-DNA viruses. CRESS-DNA viruses are associated with a wide range of diseases, including diseases in economically important crops and a variety of diseases in animals. The atypical members of the realm include papillomaviruses and polyomaviruses, which are known to cause various cancers.
Some such viruses that are commonly recognized include HPV, T-cell Leukemia virus type I, and hepatitis B. Viral oncogenesis are most common with DNA and RNA tumor viruses, most frequently the retroviruses. [12] There are two types of oncogenic retroviruses: acute transforming viruses and non-acute transforming viruses.
In addition, because viruses typically produce many copies in an infected host, mutated genes can be passed on to many offspring quickly. Although the chance of mutations and evolution can change depending on the type of virus (e.g., double stranded DNA, double stranded RNA, or single stranded DNA), viruses overall have high chances for mutations.
Schematic drawing of a Herpesviridae virion. All members of the Herpesviridae share a common structure; a relatively large, monopartite, double-stranded, linear DNA genome encoding 100–200 genes encased within an icosahedral protein cage (with T=16 symmetry) called the capsid, which is itself wrapped in a protein layer called the tegument containing both viral proteins and viral mRNAs and a ...