Betaretrovirus

**Semantic type:** Virus

**Definition:** A genus of single-stranded, reverse-transcribing RNA retroviruses with type B or type C morphology. It is the genus to which the mouse mammary tumor virus (MMTV) belongs.

**Synonyms:** - Retroviruses, Type B, Mammalian - Type B Mammalian Retrovirus - Type B Virus - Type D Retrovirus