1B-01 A genome-wide screening of yeast mutants with increased efficiency of trans-kingdom conjugation between E. coli and S. cerevisiae and its application for novel gene introduction method (I)

Trans-kingdom conjugation, a phenomenon of the gene transfer from prokaryotes to eukaryotes by conjugation, has been reported in several organisms. In this study, to establish a direct gene introduction method from E. coli to yeast with effortless and high efficiency, we carried out a genome-wide screening for yeast mutants which exhibit an increased efficiency of trans-kingdom conjugation using a S. cerevisiae knock-out deletion collection. As a result of the three-step screening, we successfully isolated 22 increased mutants, which showed more than 16 folds conjugation efficiency than that of the wild type strain. Eight mutants among them showed lack of eight nuclear encoded mitochondrial genes of various functions. In addition, the trans-kingdom conjugation efficiency was successfully increased by treatments with Antimycin A, an inhibitor of electron transport chain, and Erythromycin, an inhibitor of mitochondrial translation, respectively. These facts strongly indicate the possibility that genetic and chemical inhibitions of the mitochondrial function would be an applicable method for gene introduction by trans-kingdom conjugation at least in some fungi.