Multilocus sequence typing system for the endosymbiont Wolbachia pipientis.

Area of Science:

• Microbiology
• Genetics
• Evolutionary Biology

Background:

• Wolbachia are abundant intracellular bacteria with a broad host range in arthropods and nematodes.
• Accurate strain identification is crucial for understanding Wolbachia's population genetics and evolutionary dynamics.

Purpose of the Study:

• To develop a universal multilocus sequence typing (MLST) scheme for genotyping Wolbachia.
• To assess the genetic diversity and population structure of Wolbachia strains.

Main Methods:

• Developed an MLST scheme using internal fragments of five ubiquitous genes (gatB, coxA, hcpA, fbpA, ftsZ).
• Designed primers to amplify across major Wolbachia supergroups and divergent lineages.
• Developed a supplemental typing system using Wolbachia surface protein (WSP) hypervariable regions.
• Characterized 37 Wolbachia strains from supergroups A, B, D, and F using MLST and WSP.

Main Results:

• The MLST scheme revealed high genetic diversity, with 25-31 alleles per locus and 35 unique allelic profiles found.
• Confirmed high levels of recombination in chromosomal genes.
• MLST effectively detected strain diversity within host species and identified closely related strains across different arthropod hosts.
• Identical or similar WSP sequences did not always correlate with similar MLST profiles, highlighting MLST's importance for accurate identification.

Conclusions:

• The developed MLST system is a universal and unambiguous tool for Wolbachia strain typing.
• This method is valuable for population genetics and molecular evolutionary studies of Wolbachia.
• The study provides a robust framework for future research on Wolbachia diversity and evolution.