The trends in the spread of simple sequence repeats in the genomes of Schizophyllum commune

Abstract

ABSTRACT Due to their high number and variety, simple sequence repeats in DNA are a valuable source of genetic markers widely used in population genetics, genetic diversity, and fingerprinting. Schizophyllum commune is a cosmopolitan basidiomycete and a valuable object for biotechnology and mycology. It is often used as a model organism in genetic and population studies. Numerous genome sequences of S. commune are available in the National Center for Biotechnology Information (NCBI) database, allowing for a meticulous study of the distribution of simple tandem nucleotide repeats in the genomes of different strains, based on their origin. Analysis of the average density of simple tandem repeats in the genomes of S. commune fungi reveals the division of cultures into groups based on the USA, Ru (Russian Federation), and EA (South Korea, Japan, China) populations. Intensive point mutations lead to the accumulation and dominance of mononucleotide (C)n and dinucleotide (CG)n motifs in fungal genomes. Results show that the GCT motif contributes more to the divergence of the Ru population, whereas CTC, GAG, and GGA motifs contribute to the divergence of the USA population. Strains MG53 (China) and IUM1114-SS01 (South Korea: Incheon) from the EA population occupy a separate position, mainly because of the CGA motif. The divergence in quantitative traits of motifs between populations provides evidence of the evolutionary transformation of fungal genomes under environmental factors.