title: Excision of a selectable marker gene in transgenic banana using a Cre/lox system controlled by an embryo specific promoter.
abstract: Antibiotic and herbicide resistance genes have been used in transgene technology as powerful selection tools. Nonetheless, once transgenic events have been obtained their presence is no longer needed and can even be undesirable. In this work, we have developed a system to excise the selectable marker and the cre recombinase genes from transgenic banana cv. 'Grande Naine' (Musa AAA). To achieve this, the embryo specific REG-2 promoter was isolated from rice and its expression pattern in banana cell clumps, somatic embryos and regenerated plantlets was characterized by using a pREG2::uidA fusion construct. Subsequently, the REG-2 promoter was placed upstream of the cre gene, conferring Cre functionality in somatic embryos and recombination of lox sites resulting in excision of the selectable marker and cre genes. PCR analysis revealed that 41.7 % of the analysed transgenic plants were completely marker free, results that were thereafter confirmed by Southern blot hybridization. These results demonstrate the feasibility of using developmentally controlled promoters to mediate marker excision in banana. This system does not require any extra handling compared to the conventional transformation procedure and might be useful in other species regenerating through somatic embryogenesis.
authors.affiliation: Instituto de Biotecnología de Las Plantas, Universidad Central Marta Abreu de Las Villas, Carretera A Camajuaní Km 5.5, Santa Clara, Villa Clara, Cuba.
authors.forename: Borys
authors.initials: B
authors.lastname: Chong-Pérez
authors.forename: Maritza
authors.initials: M
authors.lastname: Reyes
authors.forename: Luis
authors.initials: L
authors.lastname: Rojas
authors.forename: Bárbara
authors.initials: B
authors.lastname: Ocaña
authors.forename: Adolfo
authors.initials: A
authors.lastname: Ramos
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Kosky
authors.forename: Geert
authors.initials: G
authors.lastname: Angenon
mesh_terms: D001483:Base Sequence; D017343:Genes, Plant; D005819:Genetic Markers; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D005916:Globulins / Q000235:genetics / Q000378:metabolism; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D028521:Musa / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D058439:Plant Somatic Embryogenesis Techniques; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012639:Seeds / Q000235:genetics* / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D005819:Genetic Markers; D005916:Globulins; D010940:Plant Proteins; C045073:Cre recombinase; D019426:Integrases