Secondary structure of the ITS2 region of the ribosomal DNA of micromycetes section Sclerotiorum as an additional phylogenetic marker

Aim. The phylogeny of microscopic fungi of the genus Penicillium of the section Sclerotiorum is still poorly understood. Therefore, the aim of the study was to build a consensus model of the secondary structure of the ITS2 rDNA region based on a representative species of P. bilaiae and closely related fungal species and to determine the possibility of its use as an additional phylogenetic marker. Methods. The methods used in the study were comparative analysis of primary DNA sequences, construction of their secondary structure based on the least free energy (MFE RNAfold) and analysis of conserved structures and mutation points. Results. The ITS2 region of the Sclerotiorum серії Adamentziorum section consists of 150–170 bp. The secondary structure according to MFE RNAfold forms three classical hairpins. The sequence of the second loop from the 5'-end of the structure was recognized as crucial for the identification of the studied species. Conclusions. The secondary structure of the ITS2 region of rDNA can be used as an additional marker for the molecular identification of P. bilaiae and closely related representatives of the section Sclerotiorum.