Giant Viruses Give the Big Picture Researcher Chantal Abergel Explains What Giant Viruses Show Us

Chantal Abergel studies giant viruses, which are a relatively new discovery. She tells listeners how the size offers new observations in virology. She explains

• Why preconceptions of virus properties delayed their discovery,
• What functions and processes the larger size enables researchers to observe, and
• What these things may tell researchers about virus and cell coevolution.

Chantal Abergel is the Research Director of the French National Centre for Scientific Research (CNRS). She achieved her Ph.D. in Material Science in 1990 from Aix Marseille University. Dr. Abergel co-founded the Structural and Genomic Information (IGS) Laboratory at the CNRS. She specializes in a study new to virology, namely giant viruses. She tells listeners that their very size made them undetectable previously because of filtration measures assuming a certain size, which kept these viruses out of the literal scope of study.

Dr. Abergel shares many traits and processes of the families they've been able to identify thus far. For example, bigger viruses are more complex with genomes that can be as large as 2.5 million base pairs. She gives a bit of the history, telling listeners about the first giant virus discovery called the Mimivirus as well as the family she's currently studying, the Pandoravirus. Their size makes them easier to isolate and observe. Dr. Abergel and her colleagues are studying their relationship with amoeba and have observed processes such as the capsid opening and contents transferring into the cell cytoplasm. Some explains that some viruses divide up and reproduce in the cytoplasm and some transfer and unfold into the nucleus and use cell machinery to duplicate.

She shares many fascinating processes that have implications about giant virus evolution. For example, after causing the overexpression of nuclear proteins inside of amoeba to address the question of whether the viruses are really cytoplasmic replicators, they observed the transcription machinery was not in the virus capsid and the virus didn't enter the cell nucleus to replicate. Rather they observed proteins leaving the nucleus of the amoeba and going to the virus for transcription. She remarks that this implies that these viruses may have been independent of the cell and this is a demonstration of how they coevolved.

To learn more, see her lab web page at CNRS, http://www.igs.cnrs-mrs.fr/en/the-lab/?lang=en, and search for her articles, which include pictures of some of these recorded processes.