Saccharomyces cerevisiae virus L-A

Saccharomyces cerevisiae virus L-A, also called L-A helper virus, is a member of the Totivirus genus of viruses found primarily in Saccharomyces cerevisiae. Its discovery in the 1970s was the main starting point of research on yeast virology.

Source: Wikipedia — Saccharomyces cerevisiae virus L-A (CC BY-SA 4.0)