Tandem repetitive transgenes and fluorescent chromatin tags alter local interphase chromosome arrangement in Arabidopsis thaliana.
Fluorescent protein chromatin tagging as achieved by the lac operator/lac repressor system is useful to trace distinct chromatin domains in living eukaryotic nuclei. To interpret the data correctly, it is important to recognize influences of the tagging system on nuclear architecture of the host cells. Within an Arabidopsis line that carries lac operator/lac repressor/GFP transgenes, the transgene loci frequently associate with each other and with heterochromatic chromocenters. Accumulation of tagged fusion protein further enhances the association frequency. Independent experiments with a transgenic plant carrying another multi-copy transgene also revealed, independent of its transcriptional state, unusually high frequencies of association with each other and with heterochromatin. From these results we conclude that the lac operator/lac repressor chromatin tagging system may alter the spatial chromatin organization in the host nuclei (in particular when more than one insertion locus is present) and also that loci of homologous transgenic repeats associate more often with each other and with endogenous heterochromatin than normal euchromatic regions.
Pecinka
Ales
A
Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, 06466 Gatersleben, Germany.
Kato
Naohiro
N
Meister
Armin
A
Probst
Aline V
AV
Schubert
Ingo
I
Lam
Eric
E
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping / Q000379:methods; D032461:Chromosomes, Plant / Q000235:genetics*; D020224:Expressed Sequence Tags / Q000378:metabolism; D005456:Fluorescent Dyes; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase / Q000235:genetics; D007763:Lac Operon / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D020080:Tandem Repeat Sequences / Q000235:genetics*; D019076:Transgenes / Q000235:genetics*
D002843:Chromatin; D005456:Fluorescent Dyes; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins