L'utilisation du système CRISPR-Cas9 pour l'étude des protéines non structurales du bactériophage 2972 infectant Streptococcus thermophilus

Authors: Renaud, Ariane
Advisor: Moineau, Sylvain
Abstract: Bacterial viruses are master manipulators of bacterial cells. They are able to take complete control of a bacterium, bypassing bacterial immune systems, hijacking core transcription and translation machinery, and typically resulting in lysis of the host. Although the major steps of phage replication are well understood, very little is known about the mechanisms of the host-cell takeover. Despite phages having relatively small and 'simple' genomes, generally only the structural proteins have been well characterized. In contrast, non-structural proteins, which include those involved in host cell takeover, tend to be completely uncharacterized. This is certainly the case for the model of Streptococcus thermophilus phages, 2972, which infects the strain DGCC7710 widely used by the dairy industry. Its genome encodes for 44 putative proteins, 14 of which are non-structural and have no known function. In this master thesis, the type II-A CRISPR-Cas system naturally present in S. thermophilus was used for genome engineering purposes to investigate the role of non-structural proteins of phage 2972. This natural bacterial immune system provides an ideal means for genetic manipulation of virulent phages, which are otherwise intractable. This could lead to potentially valuable discoveries allowing us to further fine-tune the bacteria used in various biological processes.
Document Type: Mémoire de maîtrise
Issue Date: 2019
Open Access Date: 3 February 2021
Permalink: http://hdl.handle.net/20.500.11794/67934
Grantor: Université Laval
Collection:Thèses et mémoires

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