Endogenous retrovirus

Common card · No. 371132

Endogenous retroviruses (ERVs) are endogenous viral elements in the genome that closely resemble and can be derived from retroviruses. They are abundant in the genomes of jawed vertebrates, and comprise up to 5–8% of the human genome (lower estimates of 3%). ERVs are vertically inherited proviral sequences, and they form a subclass of a type of gene called transposons, which can normally be packaged and moved within the genome to serve a vital role in gene expression and in regulation. ERVs, however, lack most transposon functions, are typically not infectious, and are often defective genomic remnants of the retroviral replication cycle. They are distinguished as germline provirus retroelements due to their integration and reverse-transcription into the nuclear genome of the host cell. Researchers have suggested that retroviruses evolved from a type of transposon called a retrotransposon, a Class I element; these genes can mutate and instead of moving to another location in the genome,...

Read on Wikipedia · Image Classes_of_ERVs.jpg: Jern P, Sperber GO, Blomberg J derivative work: Fgrammen (talk), CC BY 2.0