Prof. Sun Baolin and his team constructed a gene knockdown system in S. aureus based on dCas9

  • [2017-04-20]
  • 2017.04. , Prof. Sun Baolin published an article entitled " Construction of a Gene Knockdown System Based on Catalytically Inactive (“Dead”) Cas9 (dCas9) in Staphylococcus aureus " in Applied and Environmental Microbiology, which has been selected for inclusion in "Spotlight". Prof. Sun and his team constructed an efficient and simple gene knockdown system called CRISPRi (CRISPR inteference) in S. aureus based on a RNA-guided DNA binding protein, dCas9. Specific gene knockdown can be achieved with the co-expression of dCas9 and a small guide RNA (sgRNA) complementary to the target gene.
    Author:Changlong Zhao, Xueqin Shu, Baolin Sun
    Abstract: There has been constant absence of an efficient gene knockdown method in the important human pathogen Staphylococcus aureus like RNA interference in eukaryotes. The early developed antisense RNA technology is mainly applied for forward genetic screen, but is rather limiting in specific gene knockdown for the lack of rational antisense RNAdesign strategies. Here we report an efficient and specific gene knockdown system in S. aureus based on type II clustered regularly interspaced short palindromic repeats (CRISPR) system from Streptococcus pyogenes. We can achieve gene silencing with the co-expression of dCas9, an RNA-guided DNA binding protein, and a small guide RNA complementary to the target gene. With this system, we have successfully silenced diverse sets of genes varying in size and expression level in different S. aureus strains. This system exhibited high efficiency for knockdown of both essential and non-essential genes, and its effect is inducible and reversible. In addition, the system can repress expression of multiple genes simultaneously and silence an entire operon or part of it. This RNA-guided DNA targeting system thus provides a simple, rapid, and affordable method for selective gene knockdown in S. aureus.
    DOI information: 10.1128/AEM.00291-17