Reverse transcriptase of rat liver associated with the endogenous retrovirus related to the mouse intracisternal A-particles

Reverse transcriptase activity was found in rat liver enclosed in virus-like particles. Through hybridization with DNA probes of A- and C-type retroviruses and with the help of electron microscopy the virus-like particles have been identified as endogenous retroviruses related to the mouse intracisternal A-particles. Blot hybridization revealed the provirus DNA in the rat genome. The enzyme was isolated from the virus-like particles, purified and characterized. The main properties of the enzyme resemble those of the mammalian retrovirus reverse transcriptase.