Relationship between allelic state of T-DNA and DNA methylation of chromosomal integration region in transformed Arabidopsis thaliana plants.
T-DNA insertions are currently used as a tool to introduce, or knock out, specific genes. The expression of the inserted gene is frequently haphazard and up to now, it was proposed that transgene expression depends on the site of insertion within the genome, as well as the number of copies of the transgene. In this paper, we show that the allelic state of a T-DNA insertion can be at the origin of epigenetic silencing. A T-DNA insertional mutant was characterized to explore the function of AtBP80a', a vacuolar sorting receptor previously associated with germination. Seeds homozygous for the T-DNA do not germinate, but this can be overcome by a cold treatment and maintained by the following generations. The non-germinating phenotype is only observed in homozygous seed produced by heterozygous plants indicating that it is correlated with the allelic state of the T-DNA in parental lines. Analysis of the region between the T-DNA insertion and the ATG codon of atbp80a' showed that cytosine methylation is highly enhanced in chromatin containing the T-DNA. Data presented here show that an unpaired DNA region during meiosis could be at the origin of a de novo cytosine methylation mechanism.
Masclaux
Frédéric G
FG
UMR 5546 CNRS-Université Paul Sabatier, Pôle de Biotechnologie végétale, 24 chemin de Borde-Rouge, BP42617, 31326 Castanet-Tolosan, France.
Pont-Lezica
Rafael
R
Galaud
Jean-Philippe
JP
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics*; D019175:DNA Methylation; D004269:DNA, Bacterial / Q000235:genetics*; D018525:Germination / Q000235:genetics; D006720:Homozygote; D008855:Microscopy, Electron, Scanning; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure; D033921:Vesicular Transport Proteins / Q000235:genetics
D029681:Arabidopsis Proteins; C505595:BP80a protein, Arabidopsis; D004269:DNA, Bacterial; C036483:T-DNA; D033921:Vesicular Transport Proteins