Yeast Plasmid Vectors, Eukaryotic System, Yeast Centromere, Integrative Transformaion, Chemirc Plasmid, Frequency Transformation

	Yeast Plasmid Vectors Special vectors are also known for introducing DNA segments in yeast cells, a eukaryotic system that has been used extensively for developing genetically engineered yeast cells. Although E.coli plasmids or phages can be used for transfer of genes to yeast cells, the frequency of transformation is rather low.
For instance, yeast cells that are LEU- (lacking the ability to synthesize leucine) could be transformed using chimeric plasmid carrying LEU + gene from yeast. This involves integrative transformation (crossing over) having low frequency. To over come this difficulty of low frequency transformation, efforts were made to prepare a variety of vectors for yeast