Abstract
Endogenous retroviruses (ERVs) contribute to a range of mutations in mammals. However, autonomous retrotransposition of ERV has not been demonstrated in the rat genome.
We cloned an insertion that disrupted Cntrob gene and identified it as a novel endogenous retrovirus (RnERV-K8e family). This family is closely related to the recently reported MmERV-K10c elements.
We also identified a novel, unexpectedly close relative of RnERV-K8e in the mouse, suggesting cross-species transmission. We cloned a potentially autonomous RnERV-K8e element demonstrated that it is capable of retrotransposition.
This particular element encodes an envelope gene (env), which is not required for retrotransposition. A number of RnERV-K8e-associated genetic polymorphisms was detected among inbred rat strains, suggesting ongoing activity in the rat genome.
Ongoing retrotranspositional activity may significantly add to genomic variability among inbred rat strains.