Project description:Transcriptome sequencing was carried out on an Illumina HiSeq platform to investigate the activation of CRISPR-Cas and DNA repair systems by Csa3a in Sulfolobus islandicus Rey15A. We compared the differently expressed genes in Sulfolobus islandicus Rey15A strain with csa3a overexpression vs. Sulfolobus islandicus Rey15A strain carrying an empty expression vector, cas1 deletion strain with csa3a overexpression vs. cas1 deletion strain carrying an empty expression vector, as well as interference-deficient strain with csa3a overexpression vs. interference-deficient strain carrying an empty expression vector. We find that cas genes (SiRe_0760, SiRe_0761, SiRe_0762, SiRe_0763), nucleotidyltransferase domain of DNA polymerase beta (SiRe_0459), chromosome segregation protein (SMC)-related ATPase (SiRe_0649), SMC-related protein (SiRe_1142) and three HerA helicases involved in DNA double break repair (encoded by SiRe_0064 and SiRe_0095 of nurA-herA operons, and SiRe_1857) were significantly up-regulated. Our data indicated that the Csa3a regulator couples transcriptional activation of spacer acquisition genes, CRISPR RNA transcription, DNA repair and genome stability genes.
Project description:A whole transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich (TYS) and basal (SCV) media over a 6 day period. Spacer acquisition preceded strong host growth retardation, and changes in viral transcript abundance and virus copy numbers showed significant differences between the two media. Results showed that rich medium favoured CRISPR-Cas immunity generation.
