CRISPR/Cas9-Mediated Gene Replacement in the Fungal Keratitis Pathogen Fusarium solani var. petroliphilum
Autor: | Kevin K. Fuller, Jorge D. Lightfoot |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Microbiology (medical)
Auxotrophy ura3 gene Virulence Microbiology 03 medical and health sciences Virology CRISPR genome editing URA3 lcsh:QH301-705.5 Gene CRISPR/Cas9 030304 developmental biology 0303 health sciences biology 030306 microbiology Fusarium solani species complex Fusarium petroliphilum food and beverages biology.organism_classification Reverse genetics Contact lens lcsh:Biology (General) Fusarium solani 5-FOA |
Zdroj: | Microorganisms Volume 7 Issue 10 Microorganisms, Vol 7, Iss 10, p 457 (2019) |
ISSN: | 2076-2607 |
DOI: | 10.3390/microorganisms7100457 |
Popis: | Fungal keratitis (FK) is a site-threatening infection of the cornea associated with ocular trauma and contact lens wear. Members of the Fusarium solani species complex (FSSC) are predominant agents of FK worldwide, but genes that support their corneal virulence are poorly understood. As a means to bolster genetic analysis in FSSC pathogens, we sought to employ a CRISPR/Cas9 system in an FK isolate identified as Fusarium petroliphilum. Briefly, this approach involves the introduction of two components into fungal protoplasts: (1) A purified Cas9 protein complexed with guide RNAs that will direct the ribonuclease to cut on either side of the gene of interest, and (2) a &ldquo repair template&rdquo comprised of a hygromycin resistance cassette flanked by 40 bp of homology outside of the Cas9 cuts. In this way, Cas9-induced double strand breaks should potentiate double homologous replacement of the repair template at the desired locus. We targeted a putative ura3 ortholog since its deletion would result in an easily discernable uracil auxotrophy. Indeed, 10% of hygromycin-resistant transformants displayed the auxotrophic phenotype, all of which harbored the expected ura3 gene deletion. By contrast, none of the transformants from the repair template control (i.e., no Cas9) displayed the auxotrophic phenotype, indicating that Cas9 cutting was indeed required to promote homologous integration. Taken together, these data demonstrate that the in vitro Cas9 system is an easy and efficient approach for reverse genetics in FSSC organisms, including clinical isolates, which should enhance virulence research in these important but understudied ocular pathogens. |
Databáze: | OpenAIRE |
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