title: Direct selection of Pichia pastoris expression strains using new G418 resistance vectors.
abstract: The methylotrophic yeast, Pichia pastoris, is widely used as a host organism for the expression of heterologous proteins. Currently, the Zeocin and blasticidin resistance genes are the only dominant selectable markers that can be used for primary selection of transformants. In this report we describe new expression vectors that can be used to select directly for P. pastoris transformants using G418 resistance conferred by a modified Tn903kan(r) gene. Compared to other dominant markers, this system is more economical and offers a higher transformation efficiency, due to the small sizes of the cloning vectors, pKAN B and pKANalpha B (GenBank Accession Nos EU285585 and EU285586, respectively). Additionally, multicopy transformants can be generated using these new vectors.
authors.affiliation: Department of Biological Sciences, University of the Pacific, Stockton, CA 95211-0197, USA.
authors.forename: Joan
authors.initials: J
authors.lastname: Lin-Cereghino
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Hashimoto
authors.forename: Allison
authors.initials: A
authors.lastname: Moy
authors.forename: James
authors.initials: J
authors.lastname: Castelo
authors.forename: Claire C
authors.initials: CC
authors.lastname: Orazem
authors.forename: Peter
authors.initials: P
authors.lastname: Kuo
authors.forename: See
authors.initials: S
authors.lastname: Xiong
authors.forename: Vishal
authors.initials: V
authors.lastname: Gandhi
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Hatae
authors.forename: Alex
authors.initials: A
authors.lastname: Chan
authors.forename: Geoff P
authors.initials: GP
authors.lastname: Lin-Cereghino
mesh_terms: D003001:Cloning, Molecular; D018628:Gene Dosage; D005821:Genetic Techniques; D005822:Genetic Vectors; D005839:Gentamicins / Q000494:pharmacology*; D007612:Kanamycin / Q000494:pharmacology; D010843:Pichia / Q000187:drug effects / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000235:genetics; D012641:Selection, Genetic; D014170:Transformation, Genetic
chemical_list: D005839:Gentamicins; D012331:RNA, Fungal; D007612:Kanamycin; C010680:antibiotic G 418