title: Optimum conditions for selective isolation of genes from complex genomes by transformation-associated recombination cloning.
abstract: Transformation-associated recombination (TAR) cloning in yeast is used to isolate a desired chromosomal region or gene from a complex genome without construction of a genomic library. The technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector containing short 5' and 3' gene-specific targeting hooks. Efficient gene capture requires a high yield of transformants, and we demonstrate here that the transformant yield increases approximately 10-fold when the genomic DNA is sheared to 100-200 kb before being presented to the spheroplasts. Here we determine the most effective concentration of genomic DNA, and also show that the targeted sequences recombine much more efficiently with the vector's targeting hooks when they are located at the ends of the genomic DNA fragment. We demonstrate that the yield of gene-positive clones increases approximately 20-fold after endonuclease digestion of genomic DNA, which caused double strand breaks near the targeted sequences. These findings have led to a greatly improved protocol.
authors.affiliation: Laboratory of Biosystems and Cancer, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4471, USA.
authors.forename: Sun-Hee
authors.initials: SH
authors.lastname: Leem
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Noskov
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Park
authors.forename: Seung Il
authors.initials: SI
authors.lastname: Kim
authors.forename: Vladimir
authors.initials: V
authors.lastname: Larionov
authors.forename: Natalay
authors.initials: N
authors.lastname: Kouprina
mesh_terms: D002460:Cell Line; D018244:Chromosomes, Artificial, Yeast / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods*; D004247:DNA / Q000235:genetics; D005796:Genes / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D015894:Genome, Human; D006801:Humans; D011995:Recombination, Genetic / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D004247:DNA