Persistent viral infection in the Drosophila fat body is associated with immune activation at the single cell level.

Abstract

Viruses are ubiquitous and can spread in two main ways: vertically, which involves transmission through or associated with gametes, and horizontally, which occurs through direct contact, airborne transmission, or indirect contact, such as through ingestion. Vertically transmitted, low virulence viruses can go undetected by both the immune system and researchers, and cause chronic, asymptomatic infections. In many Drosophila studies, researchers are unaware or ambivalent about the fact that the flies used may be infected with persistent viruses. Although they often have minimal or no observable fitness costs in laboratory fly samples, recent studies suggest that an increase in viral titer is associated with a decrease in lifespan.