Donor yeast strain for transfer of genetic material
First Claim
1. A yeast cell comprising chromosomes I through XVI, wherein at least two chromosomes comprise a nucleic acid sequence encoding a counterselectable marker linked to a centromere.
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Abstract
The invention provides a universal yeast donor strain that contains a conditional centromere and a URA3 allele on every chromosome. This strain was constructed in four rounds of crosses of individual conditional chromosome strains using a novel tetrad-based screen to identify segregants in which all marked chromosomes were contained in the same spore. The invention also provides an improved high efficiency method to transfer extrachromosomal genetic material such as plasmid DNA into any Saccharomyces strain for use with the current gene disruption libraries. The method of transfer is mating-based method which uses a kar1 plasmid donor strain that can initiate mating but cannot form a diploid and allows plasmid transfer (plasmoduction) between nuclei in the heterokaryon. kar1 matings have been used to transfer YACs between yeast strains, but previous methods required specialized genetic backgrounds in the recipient strains and suffered from high rates of spurious chromosome transfer (Hugerat, Y., et al. 1994. Genomics 22:108). Plasmoduction with the universal donor strain only requires that the recipient strain be ura3, GAL+ and have another marker available for selection of the transferred plasmid. Counterselection against every donor chromosome also limits the amount of spurious allele transfer. The universal donor strain and the method of the invention are used to screen the yeast gene disruption library with plasmid-based dominant negative alleles of various genes.
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Citations
22 Claims
- 1. A yeast cell comprising chromosomes I through XVI, wherein at least two chromosomes comprise a nucleic acid sequence encoding a counterselectable marker linked to a centromere.
- 2. A yeast cell comprising chromosomes I through XVI, wherein each chromosome comprises a nucleic acid sequence encoding a counterselectable marker linked to a centromere.
Specification