Publications des scientifiques de l'IRD

Gallet R., Di Mattia J., Ravel S., Zeddam Jean-Louis, Vitalis R., Michalakis Y., Blanc S. (2022). Gene copy number variations at the within-host population level modulate gene expression in a multipartite virus. Virus Evolution, 8 (2), veac058 [11 p.].

Titre du document
Gene copy number variations at the within-host population level modulate gene expression in a multipartite virus
Année de publication
2022
Type de document
Article référencé dans le Web of Science WOS:000820799800001
Auteurs
Gallet R., Di Mattia J., Ravel S., Zeddam Jean-Louis, Vitalis R., Michalakis Y., Blanc S.
Source
Virus Evolution, 2022, 8 (2), veac058 [11 p.]
Multipartite viruses have a segmented genome, with each segment encapsidated separately. In all multipartite virus species for which the question has been addressed, the distinct segments reproducibly accumulate at a specific and host-dependent relative frequency, defined as the 'genome formula'. Here, we test the hypothesis that the multipartite genome organization facilitates the regulation of gene expression via changes of the genome formula and thus via gene copy number variations. In a first experiment, the faba bean necrotic stunt virus (FBNSV), whose genome is composed of eight DNA segments each encoding a single gene, was inoculated into faba bean or alfalfa host plants, and the relative concentrations of the DNA segments and their corresponding messenger RNAs (mRNAs) were monitored. In each of the two host species, our analysis consistently showed that the genome formula variations modulate gene expression, the concentration of each genome segment linearly and positively correlating to that of its cognate mRNA but not of the others. In a second experiment, twenty parallel FBNSV lines were transferred from faba bean to alfalfa plants. Upon host switching, the transcription rate of some genome segments changes, but the genome formula is modified in a way that compensates for these changes and maintains a similar ratio between the various viral mRNAs. Interestingly, a deep-sequencing analysis of these twenty FBNSV lineages demonstrated that the host-related genome formula shift operates independently of DNA-segment sequence mutation. Together, our results indicate that nanoviruses are plastic genetic systems, able to transiently adjust gene expression at the population level in changing environments, by modulating the copy number but not the sequence of each of their genes.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Entomologie médicale / Parasitologie / Virologie [052]
Localisation
Fonds IRD [F B010085367]
Identifiant IRD
fdi:010085367
Contact