title: Activator mutagenesis of the pink scutellum1/viviparous7 locus of maize.
abstract: The transposable elements Activator/Dissociation (Ac/Ds) were first discovered in maize, yet they have not been used extensively in their native host for gene-tagging experiments. This can be attributed largely to the low forward mutation rate and the propensity for closely linked transpositions associated with Ac and its nonautonomous deletion derivative Ds. To overcome these limitations, we are developing a series of nearly isogenic maize lines, each with a single active Ac element positioned at a well-defined location. These Ac elements are distributed at 10- to 20-centimorgan intervals throughout the genome for use in regional mutagenesis. Here, we demonstrate the utility of this Ac-based gene-tagging approach through the targeted mutagenesis of the pink scutellum1/viviparous7 (ps1/vp7) locus. Using a novel PCR-based technique, the Ps1 gene was cloned and Ac elements positioned precisely in each of the seven alleles recovered. The Ps1 gene is predicted to encode lycopene beta-cyclase and is necessary for the accumulation of both abscisic acid and the carotenoid zeaxanthin in mature maize embryos. This study demonstrates the utility of an Ac mutagenesis program to efficiently generate allelic diversity at closely linked loci in maize.
authors.affiliation: Boyce Thompson Institute, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Manjit
authors.initials: M
authors.lastname: Singh
authors.forename: Paul E
authors.initials: PE
authors.lastname: Lewis
authors.forename: Kristine
authors.initials: K
authors.lastname: Hardeman
authors.forename: Ling
authors.initials: L
authors.lastname: Bai
authors.forename: Jocelyn K C
authors.initials: JK
authors.lastname: Rose
authors.forename: Michael
authors.initials: M
authors.lastname: Mazourek
authors.forename: Paul
authors.initials: P
authors.lastname: Chomet
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Brutnell
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D002338:Carotenoids / Q000378:metabolism; D004251:DNA Transposable Elements / Q000235:genetics; D019753:Intramolecular Lyases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000379:methods*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D024341:Xanthophylls; D003313:Zea mays / Q000201:enzymology / Q000235:genetics*; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D010940:Plant Proteins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D000040:Abscisic Acid; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase