Browsing by Subject "säätelytekijä"

The tRNA-derived fragments (tsRNAs) are known to play a role in protein translation and post-transcriptional regulation. Viruses exploit the cellular machinery of the host for their replication and therefore the formation of tRNA-derived fragments could be one mechanism utilized by the virus for completing the infection cycle. Virus-induced tRNA-derived fragments have so far been found to suppress the antiviral responses of the host or to favor viral protein translation. However, the biogenesis of tsRNAs, their virus specificity, as well as their putative regulatory roles during infection are still mainly unknown. Research into the roles of tsRNAs in viral infection has enormous potential to reveal novel regulatory functions of tsRNAs and shed light on the mechanisms which viruses utilize to hijack the cellular translation machinery. This Master’s thesis project aimed to investigate the possible regulatory role and the origin of infection-induced tRNA-fragments in Shewanella glacialimarina TZS-4T. S. glacialimarina was infected with Shewanella phage isolate 1/4 and total RNA was isolated from culture samples collected at different timepoints after infection. Additionally, to assess the specificity of the phenomena, S. frigidimarina and S. baltica, two evolutionary close relatives of S. glacialimarina, were also infected with Shewanella phage isolate 1/4. The formation of fragments was found to be dynamic and specific to S. glacialimarina. The observed fragments were further purified from the total RNA and sequenced using an adapted protocol for sequencing library preparation to identify the origin of the fragments. As a result of this thesis, the adapted protocol was further optimized for the fragment isolation, yet the full identification of the sequences was not achieved within the timeframe of this project.