Scooter, a New Active Transposon in Schizophyllum commune, Has Disrupted Two Genes Regulating Signal Transduction

Abstract

Two copies of scooter, a DNA-mediated transposon in the basidiomycetous fungus Schizophyllum commune, were characterized. Scooter is the first transposon isolated from S. commune. Scooter creates 8-bp target site duplications, comparable to members of the hAT superfamily, and has 32-bp terminal inverted repeats. Both copies of scooter are nonautonomous elements capable of movement. Southern blot hybridizations show that scooter-related sequences are present in all S. commune strains tested. Scooter-1 was identified initially as an insertion in the Bβ2 pheromone receptor gene, bbr2, leading to a partial defect in mating. Scooter-2 spontaneously disrupted a gene to produce the frequently occurring morphological mutant phenotype known as thin. The scooter-2 insert permitted cloning of the disrupted gene, thn1, which encodes a putative regulator of G protein signaling (RGS) protein. Spontaneous insertion of scooter into genes with identifiable mutant phenotypes constitutes the first evidence of active transposition of a DNA-mediated transposon in a basidiomycete.

Evolutionary Morphogenesis of Sexual Fruiting Bodies in Basidiomycota: Toward a New Evo-Devo Synthesis

“…The spontaneous thn1 mutation of S. commune suppresses aerial hyphae and subsequent fruiting body formation (145,225). thn1 encodes a GTPase activating protein that negatively regulates G-protein signaling (226). Its deletion in S. commune revealed that thn1 is involved in multiple processes, such as the temporal coordination of clamp cell (see Glossary) formation, the production of certain metabolites, and the induction several hydrophobins (e.g., Sc3 [224]).…”

Composition and Diversity of LTR Retrotransposons in the Coffee Leaf Rust Genome (Hemileia vastatrix)

“…Together with a significant expression found in RNAseq data, Soroa could have a significant impact on the functions and expressions of genes. Several mutations induced by TE insertions were reported in fungi, with negative or positive effects [65,73]. However, an analysis of 625 publicly available fungal genomes [66] identified numerous overlaps between the TE remnants and coding genes, but had no correlation with gene function.…”