ИСТИНА

Basidiomycete Schizophyllum commune is a unique organism with the highest known genetic diversity, such that per-nucleotide heterozygosity level can reach 20% within a single population. Polymorphism level is instrumental in many genomic applications, ranging from studies of recombination to GWASes. Together with small genome length (38.5 Mb), this makes S. commune a promising system to study a range of evolutionary processes with resolution that was previously unachievable. In this project, we aim to address how the homologous recombination rate depends on the level of heterozygosity in S. commune. It was previously shown that recombination in this fungus tends to occur within more conserved regions – in particular, genes [1]. Following this observation, we assumed that in homozygous regions homologous recombination rate might be higher than that in heterozygous regions. We developed an experimental system in which we can directly measure the recombination rate in completely homozygous regions, and compare it to the normal recombination rate in regions with high heterozygosity. We saw no significant evidence that the recombination rate in completely homozygous regions is higher than that in heterozygous regions. 1. V. Seplyarskiy et al. (2014) Crossing-Over in a Hypervariable Species Preferentially Occurs in Regions of High Local Similarity, MBE, 31:3016–3025.