Single-step selection for Ty1 element retrotransposition.
The yeast retrotransposon Ty1 has been tagged with a reporter gene that allows selection of RNA-mediated transposition events and is applicable to the study of retroelements in other organisms. The reporter gene is a yeast HIS3 gene interrupted by an artificial intron (AI) in the antisense orientation. The HIS3AI sequences were inserted into a Ty1 element such that the intron is on the sense strand of the Ty1 element; therefore, splicing and retrotransposition of marked Ty1 transcripts can give rise to His+ cells. Fusion of the Ty1-H3mHIS3AI element to the inducible GAL1 promoter resulted in a high frequency of histidine prototrophs upon galactose induction. Moreover, spontaneous His+ revertants derived from strains containing genomic TymHIS3AI elements are a result of retrotransposition. By using this assay, we estimated the Ty1 transposition rate to be between 3 x 10(-7) and 1 x 10(-5) transpositions per Ty1 element per generation. Variations in the transposition rate of individual Ty1 elements are correlated with the relative abundance of their transcripts.
Curcio
M J
MJ
Advanced BioScience Laboratories-Basic Research Program, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201.
Garfinkel
D J
DJ
D015152:Blotting, Northern; D004251:DNA Transposable Elements; D005800:Genes, Fungal; D007438:Introns; D010641:Phenotype; D010957:Plasmids; D012331:RNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D004251:DNA Transposable Elements; D012331:RNA, Fungal