title: Gene stacking in transgenic plants: towards compliance between definitions, terminology, and detection within the EU regulatory framework.
abstract: The combination or stacking of different traits or genes in plants is rapidly gaining popularity in biotech crop production. Here we review the existing terminology regarding gene stacking in plants, and its implications in relation to genetics, biosafety, detectability and European regulations. Different methods of production of stacked gene traits, as well as the status of their cultivation and approval, are reviewed. Related to the different techniques of transformation and production, including classical breeding, and to differences in global authorization and commercialization practices, there are many types, definitions, and perceptions of stacking. These include: (1) stacking of traits and (2) stacking of events, which are the most widely accepted perceptions of stacking, and (3) stacking of genes, which from the analytical and traceability point of view may be a more appropriate perception. These differences in perceptions and definitions are discussed, as are their implications for analytical detection and regulatory compliance according to (in particular) European Union (EU) regulations. A comprehensive terminology regarding gene stacking with regulatory relevance is proposed. The haploid genome equivalent is proposed as the prevailing unit of measurement at all stages throughout the chain, in order to ensure that terminology and definitions of gene stacks are adapted to analytical detection, traceability, and compliance with EU regulations.
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Unit Technology and Food (T&V), Burg. Van Gansberghelaan 115 bus 2, 9820 Merelbeke, Belgium. isabel.taverniers@ilvo.vlaanderen.be
authors.forename: Isabel
authors.initials: I
authors.lastname: Taverniers
authors.forename: Nina
authors.initials: N
authors.lastname: Papazova
authors.forename: Yves
authors.initials: Y
authors.lastname: Bertheau
authors.forename: Marc
authors.initials: M
authors.lastname: De Loose
authors.forename: Arne
authors.initials: A
authors.lastname: Holst-Jensen
mesh_terms: D000383:Agriculture / Q000639:trends*; D004274:DNA, Recombinant / Q000032:analysis; D005062:European Union; D005818:Genetic Engineering / Q000331:legislation & jurisprudence / Q000639:trends*; D033161:Government Regulation; D030821:Plants, Genetically Modified / Q000235:genetics*; D009626:Terminology as Topic; D019076:Transgenes
chemical_list: D004274:DNA, Recombinant