σmarY1, the LTR of the gypsy-type retroelement marY1 from the basidiomycete Tricholoma matsutake, allows multicopy DNA integration in Lentinula edodes

Abstract

σmarY1 is the LTR of the retroelement marY1 from the homobasidiomycete Tricholoma matsutake. Upon integration through transformation, pLC1-hph carrying a σmarY1 derivative, σ* marY1, conferred the hygromycin-resistant phenotype stronger than the vector without σ*marY1 on Lentinula edodes. Based on the densitometric analysis after Southern hybridization, a copy number of the former construct integrated in the genome is much higher than that of the latter. We conclude that σmarY1 allows multicopy DNA integration and will be useful in the genetic research on this fungal group.