Flagellin gene sequence variation in the genus Pseudomonas.

Area of Science:

• Microbiology
• Molecular Biology
• Evolutionary Biology

Background:

• The flagellin gene (fliC) is a key component of bacterial flagella and is used in phylogenetic analysis.
• Pseudomonas species are ubiquitous bacteria with significant ecological and clinical relevance.
• Understanding evolutionary relationships within Pseudomonas is crucial for taxonomy and functional studies.

Purpose of the Study:

• To compare flagellin gene (fliC) sequences from various Pseudomonas strains and other gamma-proteobacteria.
• To evaluate the reliability of fliC sequences for inferring phylogenetic relationships within the Pseudomonas genus.
• To investigate potential recombination events within the fliC gene.

Main Methods:

• Sequencing and comparative analysis of N-terminal, C-terminal, and whole flagellin gene (fliC) sequences.
• Comparison of fliC-based phylogenetic inferences with those derived from 16S rRNA gene sequences.
• Analysis of sequence similarities and variability within the central domain of the fliC gene.

Main Results:

• fliC analyses corroborated some relationships inferred from 16S rRNA, such as between P. mendocina, P. oleovorans, and P. aeruginosa.
• Inconsistencies were observed in phylogenetic relationships depending on the fliC region analyzed (whole gene vs. terminal regions).
• Evidence suggests potential recombination in the central domain of Pseudomonas fliC genes, both within and between species.

Conclusions:

• Phylogenetic inferences based solely on fliC sequences should be treated with caution due to observed inconsistencies.
• The variability and potential recombination in the fliC central domain complicate its use as a sole phylogenetic marker.
• Further investigation is needed to fully understand the evolutionary dynamics of the fliC gene in Pseudomonas.