FV1, THE MOUSE RETROVIRUS RESISTANCE GENE

A number of genes which affect the susceptibility of mice to infection by retroviruses have been described. One of the most interesting of t hese genes is Fv1(Friend virus susceptibility 1), which acts at a stag e in the retroviral life-cycle following virus entry into the cell but prior to integration and formation of proviral structures. A detailed understanding of the mode of action of Fv1 might be expected to shed fresh light on early steps of the retroviral replication, although pro gress has been slow in this area due to uncertainty about the nature o f the Fv1 gene. The recent cloning of Fvl by a positional approach fil ls this gap in current knowledge. Fvl appears to be derived from a fra gment of a retroviral genome, an observation that may suggest novel ap proaches to the control of retroviral replication.