Retroviruses

Understanding endogenous retroviruses entails a need to know what a retrovirus is. As the name indicates a retrovirus is a type of virus. It has a genome that is made of RNA rather than the more common DNA based genomes. Like other viruses it is parasitic and depends on its host for the transcription mechanism needed to replicate itself.

This link provides a concise description of retroviruses and more details about what is mentioned in this blog entry. Mentioned are three genes found in retroviral genomes- gag, pol and env. Pol genes code for a protein known as reverse transcriptase. Reverse transcriptase is critical to the viral capacity to transform its RNA genome into DNA. Another protein known as integrase enables the insertion of this DNA into the DNA of the host. Such insertions can become a permanent part of the host genome when germline cells are affected. Identification of DNA regions bearing molecular markers for retroviruses indicate endogenous retroviruses. Endogenous retroviruses are species specific and those found in human genomes are called human endogenous retroviruses or HERVs for short.

Linked here is another helpful site about retroviruses.