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DNA topoisomerase 2 gene polymorphism in dermatophytes
Forough Shamsizadeh1,2, Ivan M Pchelin3, Koichi Makimura4
1Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Mycoses
|April 12, 2020
Summary
Genetic polymorphism in dermatophytes was studied using the topoisomerase 2 (TOP2) gene. Results revealed unresolved taxonomic issues, including the polyphyly of Nannizzia species and Trichophyton simii.
Area of Science:
- Mycology
- Molecular Taxonomy
- Fungal Genetics
Background:
- Dermatophytes are medically important keratinophilic fungi.
- Existing molecular taxonomic studies highlight the need for broader genomic locus analysis.
- Genetic polymorphism data in dermatophytes remains incomplete.
Purpose of the Study:
- To investigate the partial DNA topoisomerase 2 gene (TOP2) polymorphism in dermatophytes.
- To contribute to a deeper understanding of dermatophyte genetic diversity.
- To address gaps in molecular taxonomic data for dermatophytes.
Main Methods:
- DNA sequencing of the TOP2 gene in 26 dermatophyte species.
- Ribosomal internal transcribed spacer (ITS) sequencing was performed concurrently.
- Phylogenetic analysis of concatenated TOP2-ITS data.
Main Results:
- The TOP2 dataset exhibited a similar number of polymorphic sites compared to the ITS dataset.
- Phylogenetic analysis indicated that Nannizzia species form a paraphyletic group based on TOP2 data.
- Trichophyton simii was found to be paraphyletic in the combined TOP2-ITS phylogenetic tree, with one clade exclusively containing Iranian isolates.
Conclusions:
- The study identified unresolved taxonomic challenges within dermatophytes.
- Results suggest the probable polyphyly of the genus Nannizzia.
- The species Trichophyton simii also appears to be polyphyletic, indicating complex evolutionary relationships.
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