FIG 4.

Fully induced CRISPRi targeting of essential genes results in morphological phenotypes characteristic of stress responses. (A) Median length and width for all strains after full induction of CRISPRi. Purple dots represent outer membrane-related genes. Solid red lines indicate the median width and length, and the red dashed lines indicate ±3 SD from the median, estimated from the median absolute distance. (B and C) Altered cell length and width were associated with reduced relative fitness, suggesting a connection between morphological defects and growth. Box plots show the distributions of median strain length and width within bins of 0.1 RF. tRNA synthases, represented by blue dots, exhibited short length (B) but normal width (C), consistent with the induction of the stringent response. Genes discussed in the text as exhibiting low relative fitness and filamentation are outlined by black circles.