Fig. 3: Diminished polar effect and growth retardation by the Tl-CRISPRi while targeting the endogenous operons of E. coli.
From: Tunable translation-level CRISPR interference by dCas13 and engineered gRNA in bacteria
a A diagram shows the difference between the Tx-CRISPRi and the Tl-CRISPRi while targeting the operon of non-essential genes and essential genes in series. Though the non-essential gene was targeted, the polar effect causes Tx-CRISPRi to block the expression of downstream essential genes, thus hindering bacterial growth. We speculated that the Tl-CRISPRi would not cause growth retardation while targeting the same non-essential genes. b Five different endogenous operons on the E. coli K-12 MG1655 chromosome were selected as examples, and their transcription unit is presented. c, d The cellular growth while performing Tx-CRISPRi (c) or Tl-CRISPRi (d) toward the upstream non-essential genes was compared with the strain harboring the non-target guide RNA (NT). The error bar represents the mean ± standard deviation from the biologically independent cell cultures (n = 3), and the white dots indicate the actual data points. The P-value of each strain’s dataset was determined by the two-tailed Student’s t-test compared to the dataset of the NT strain. The asterisk above the bar indicates the P-value. NS: not significant; *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Source data are provided as a source data file.
