Transformation of yeast.

TLDR

A chimeric ColE1 plasmid carrying the yeast leu2 gene was used to transform a leu2‑ strain to LEU2+, and hybridization, restriction mapping, and linkage analysis confirmed integration and chromosomal arrangement. ColE1-derived DNA integrates into yeast chromosomes, acting as a simple Mendelian element, and can insert additively or substitutively at the leu2 locus and at multiple other chromosomal sites.

Abstract

A stable leu2- yeast strain has been transformed to LEU2+ by using a chimeric ColE1 plasmid carrying the yeast leu2 gene. We have used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced. These studies show that ColE1 DNA together with the yeast sequences can integrate into the yeast chromosomes. This integration may be additive or substitutive. The bacterial plasmid sequences, once integrated, behave as a simple Mendelian element. In addition, we have determined the genetic linkage relationships for each newly introduced LEU2+ allele with the original leu2- allele. These studies show that the transforming squences integrate not only in the leu2 region but also in several other chromosomal locations.