New work out! Visualizing transcription and translation in Mimivirus during an infection cycle

Spearheaded by Lotte, we have developed a single-molecule messenger RNA fluorescence in situ hybridisation (smFISH) protocol for giant viruses in an Acanthamoeba host. Combined with other labelling techniques (FUNCAT, DiD, rRNA FISH, DAPI), we show the Mimivirus transcription and translation sites during an infection cycle in the amoeba host cell. While viral mRNA localisation changes depending on the infection stage, transcription occurs at well-defined spots within the viral factory. The original viral cores released within the cytoplasm most likely define these spots. When transported outside of the viral factory, the translation of viral mRNA takes place in a well-defined ring surrounding it. With this study, we obtained novel insights into giant virus replication, of which the methods are widely applicable to other viruses for the visualisation and quantification of RNA molecules.

Reference: 10.1101/2025.03.24.645094