Search results
Results From The WOW.Com Content Network
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. [2] After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backward).
This includes RNA viruses belonging to Group III, Group IV or Group V of the Baltimore classification system as well as Group VI. Group VI viruses are retroviruses, viruses with RNA genetic material that use DNA intermediates in their life cycle including HIV-1 and HIV-2 which cause AIDS.
However, there is a key difference between retroviruses and retrotransposons, which is indicated by the env gene. Although similar to the gene carrying out the same function in retroviruses, the env gene is used to determine whether the gene is retroviral or retrotransposon.
There are two types of oncogenic retroviruses: acute transforming viruses and non-acute transforming viruses. Acute transforming viruses induce a rapid tumor growth since they carry viral oncogenes in their DNA/RNA to induce such growth. An example of an acute transforming virus is the Rous Sarcoma Virus (RSV) that carry the v-src oncogene.
Identical LTR sequences at either end of a retrotransposon. A long terminal repeat (LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or a retroviral provirus.
The replication cycle of a retrovirus entails the insertion ("integration") of a DNA copy of the viral genome into the nuclear genome of the host cell.Most retroviruses infect somatic cells, but occasional infection of germline cells (cells that produce eggs and sperm) can also occur.
A well-studied family of this class of viruses include the retroviruses. One defining feature is the use of reverse transcriptase to convert the positive-sense RNA into DNA. Instead of using the RNA for templates of proteins, they use DNA to create the templates, which is spliced into the host genome using integrase. Replication can then ...
The use of engineered plant viruses has been proposed to enhance crop performance and promote sustainable production. [12] Replicating virus-based vectors are typically used. [63] RNA viruses used for monocots include wheat streak mosaic virus and barley stripe mosaic virus and, for dicots, tobacco rattle virus.