title: Agrobacterium-mediated transformation of maize (Zea mays) with Cre-lox site specific recombination cassettes in BIBAC vectors.
abstract: The Cre/loxP site-specific recombination system has been applied in various plant species including maize (Zea mays) for marker gene removal, gene targeting, and functional genomics. A BIBAC vector system was adapted for maize transformation with a large fragment of genetic material including a herbicide resistance marker gene, a 30 kb yeast genomic fragment as a marker for fluorescence in situ hybridization (FISH), and a 35S-lox-cre recombination cassette. Seventy-five transgenic lines were generated from Agrobacterium-mediated transformation of a maize Hi II line with multiple B chromosomes. Eighty-four inserts have been localized among all 10 A chromosome pairs by FISH using the yeast DNA probe together with a karyotyping cocktail. No inserts were found on the B chromosomes; thus a bias against the B chromosomes by the Agrobacterium-mediated transformation was revealed. The expression of a cre gene was confirmed in 68 of the 75 transgenic lines by a reporter construct for cre/lox mediated recombination. The placement of the cre/lox site-specific recombination system in many locations in the maize genome will be valuable materials for gene targeting and chromosome engineering.
authors.affiliation: Division of Biological Sciences, University of Missouri, Tucker Hall, Columbia, MO 65211, USA.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Vega
authors.forename: Weichang
authors.initials: W
authors.lastname: Yu
authors.forename: Fangpu
authors.initials: F
authors.lastname: Han
authors.forename: Akio
authors.initials: A
authors.lastname: Kato
authors.forename: Eric M
authors.initials: EM
authors.lastname: Peters
authors.forename: Zhanyuan J
authors.initials: ZJ
authors.lastname: Zhang
authors.forename: James A
authors.initials: JA
authors.lastname: Birchler
mesh_terms: D015139:Blotting, Southern; D032461:Chromosomes, Plant / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D008957:Models, Genetic; D030821:Plants, Genetically Modified; D011995:Recombination, Genetic / Q000235:genetics*; D012231:Rhizobium / Q000235:genetics*; D014170:Transformation, Genetic; D019076:Transgenes / Q000235:genetics; D003313:Zea mays / Q000235:genetics*