biorxiv.org
Advancing Vibrio genetics: A platform for efficient genomic manipulation
Most non-model Vibrio species lack the genetic tools needed for targeted mutagenesis, which limits the ability to functionally characterize newly identified pathways. To address this challenge, we present here efficient, robust methods for genetically manipulating Vibrio species that rely on RecA-mediated homologous recombination and two well-characterized counterselection methods, galactokinase (galK) 2-Deoxy-D-galactose (DOG-2) toxicity and the rpsLR/rpsLS streptomycin susceptibility system, both of which are active across a broad range of Vibrio species. We further characterized two genus-specific conserved promoters capable of driving high-level ectopic expression across all tested species. These promoters were incorporated into two broadly applicable, conjugatively transferable suicide backbones designed to facilitate double homologous recombination. Using these systems, we successfully disrupted polar flagellar motility in multiple Vibrio species and introduced extensive modifications to both flagellar and secretory pathways in V. diazotrophicus. Notably, although the galK system exhibited broader applicability, the rpsL system proved to be more efficient in cases where a streptomycin resistant strain could be generated. We also developed two mobilizable replicative backbones that express pH-stable fluorescent proteins for use within the genus. Collectively, these tools expand the genetic toolkit available for both gene disruption and heterologous gene expression in non-model members of the Vibrionaceae.
