Fig. 2

CRISPR/Cas9 genome editing systems used in A. niger. a CRISPR/Cas9 system based on RNA polymerase II promoters for sgRNA expression enables the NHEJ-mediated gene disruption in A. niger [84]. b CRISPR/Cas9 system utilizing in vitro transcription for sgRNA synthesis enables the HR-mediated gene deletion with 1.5 kb homologous arm as donor DNA [85, 86]. c CRISPR/Cas9 systems based on RNA polymerase III promoters (U6 and 5S rRNA promoters) for sgRNA expression facilitate the NHEJ-mediated gene disruption and HR-mediated gene insertion and deletion with 40 bp micro-homologous arms as donor DNA [88, 89]