The NSm proteins of Rift Valley fever virus are dispensable for maturation, replication and infection

Rift Valley fever (RVF) virus belongs to the Bunyaviridae family of segmented negative-strand RNA viruses and causes mosquito-borne disease in sub-Saharan Africa. We report the development of a T7 RNA polymerase-driven plasmid-based genetic system for the virulent Egyptian isolate, ZH501. We have used this system to rescue a virus that has a 387 nucleotide deletion on the genomic M segment that eliminates the coding region for two non-structural proteins known as NSm. This virus, Delta NSm rZH501, is indistinguishable from the parental ZH501 strain with respect to expression of structural proteins and growth in cultured mammalian cells. Published by Elsevier Inc.