May 20, 2020
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
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
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.