A natural allele of Nxf1/TAP supresses retrovirus insertional mutations

Endogenous retroviruses have shaped the evolution of mammalian genomes. Host genes that control the effects of retrovirus insertions are therefore of great interest. The Modifier-of-vibrator-1 locus controls level of correctly processed mRNA from genes mutated by endogenous retrovirus insertions into introns, including the pitpn vb tremor mutation and the Eya1 BOR model of human branchiootorenal syndrome. Positional complementation cloning identifies Mvb1 as the nuclear export factor Nxf1, providing an unexpected link between mRNA export receptor and pre-mRNA processing. Population structure of the suppressing allele in wild M. m. castaneus suggests selective advantage. A congenic Mvb1 CAST allele is a useful tool for modifying gene expression from existing mutations and could be used to manipulate engineered mutations containing retroviral elements.