Differences among chitin synthase 1 gene sequences in Trichophyton rubrum and T-violaceum

Nucleotide sequences of chitin synthase 1 (CHS1) gene were analysed for the phylogenetic relation between Trichophyton violaceum and T. rubrum, includ ing two isolates of T, raubitschekii and one isolate of T, rubrum var. nigr icans. About 620-bp genomic DNA fragments of the CHS1 gene were amplified f rom these dermatophytes by polymerase chain reaction (PCR) and sequenced. T he CHS1 nucleotide sequences of these dermatophytes showed more than 95% si milarity between the species. The phylogenetic analysis of their sequences revealed that T. rubrum was genetically distinct from T. violaceum. The spe cific restriction endonuclease site for HinfI was present in the CHS1 gene sequence of T. rubrum but not in that of T. violaceum. A molecular analysis of CHS1 genes will provide useful information for the identification of th ese Trichophyton species and the understanding of their evolution.