Fig. 2: Intact Cpx-signalling is crucial for Yptb-YPIII biofilm formation on biotic surface.

Infection and survival of N_2, a standard laboratory strain of Caenorhabditis elegans nematode on the lawn of Cpx-signalling strains. (a) L4 stage (larval) nematodes were seeded on the equalised OD₆₀₀ lawn of Gfp-expressing parental Yptb-YPIII (WT), ΔcpxA, ΔcpxR, ΔcpxP and ΔcpxA/pCpxA strains of Cpx-signalling and imaged C. elegans after 24 h of growth on each respective lawn. White arrowheads indicate Gfp-coloured dense mass of biofilm from the corresponding strain. The ∆cpxA null-mutant failed to form biofilm on the surface of C. elegans, which was restored upon ectopic expression of pCpxA. H- head and T- tail of C. elegans. A representative image from three independent biological replicates of each strain is shown. Pictures were acquired by Nikon Stereoscopic Microscope SMZ1500 with Gfp-fluorescence (excitation ƛ 470 nm and emission ƛ 525 nm) at ×50 magnification, equivalent to a 10 µm scale bar. The Pre-installed NIS Elements V4.0 imaging software was used to capture the pictures. (b) Survivability percentage of C. elegans on parental wild-type (WT) and mutant strains of Cpx-signalling. Thirty L4 stage (larval) nematodes were seeded on the equalised OD₆₀₀ lawn of WT, ΔcpxA, ΔcpxA/pCpxA, ΔcpxR and ΔcpxP strains and scoring of live nematodes was recorded every 24 h, continuous for 5 days.