title: Transformation of plant protoplasts with DNA: cotransformation of non-selected calf thymus carrier DNA and meiotic segregation of transforming DNA sequences.
abstract: With the DNA transformation procedure developed in our laboratory (13) several transformed tobacco SR1 tissues were obtained which, apart from selected and non-selected pTi sequences (T(+)), also had acquired non-selected calf thymus carrier DNA sequences (C(+)), being integrated in their nuclear genomes. From one such tissue (cNT4), with a shooty crown gall phenotype and expressing mannopine synthesis activity (Mas(+)), shoots were grafted and mature, flowering plants (gNT4) were obtained. After cross pollination with wild type SR1 tobacco pollen 49% of the seedlings obtained, had the maternal NT4-like crown gall phenotype and 51% showed wild type (SR1) features. The mannopine locus segregated independently from the locus determining the crown gall phenotype. When screened for integrated ('transforming') foreign DNA sequences 97% of the NT4-like seedlings turned out to be C(+)T(+). Most of the SR1-like seedlings, having a wild type tobacco morphology, proved to be transformed as well: roughly a 1:1:1:1 ratio as found for C(+)T(+):C(-)T(+): C(+)T:C T SR1-like seedlings. Based on the segregation of transforming sequences during meiosis a model is presented showing the integration of these sequences in three different host chromosomes.
authors.affiliation: Dept. of Plant Molecular Biology, State University of Leiden, Wassenaarseweg 64, 2333 AL, Leiden, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Peerbolte
authors.forename: F A
authors.initials: FA
authors.lastname: Krens
authors.forename: R M
authors.initials: RM
authors.lastname: Mans
authors.forename: M
authors.initials: M
authors.lastname: Floor
authors.forename: J H
authors.initials: JH
authors.lastname: Hoge
authors.forename: G J
authors.initials: GJ
authors.lastname: Wullems
authors.forename: R A
authors.initials: RA
authors.lastname: Schilperoort