Open AccessReplication of ribosomal DNA in Arabidopsis occurs both inside and outside of the nucleolus during S-phase progression
Author(s) -
Martina Dvořáčková,
Berta Raposo,
Petr Matula,
Joerg Fuchs,
Veit Schubert,
Vratislav Peška,
Bénédicte Desvoyes,
Crisanto Gutiérrez,
Jiřı́ Fajkus
Publication year - 2017
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.202416
Subject(s) - biology , nucleolus , ribosomal dna , chromatin , origin of replication , gene , transcription (linguistics) , ribosomal rna , genetics , dna replication , microbiology and biotechnology , cytoplasm , philosophy , linguistics , phylogenetics
Ribosomal RNA genes (rDNA) have been used as valuable experimental systems in numerous studies. Here we focus on elucidating the spatio-temporal organisation of rDNA replication in Arabidopsis thaliana. To determine the subnuclear distribution of rDNA and the progression of its replication during S phase, we apply a 5-ethynyl-2'-deoxyuridine (EdU) labelling, fluorescence-activated cell sorting, fluorescence in situ hybridization, and structured illumination microscopy. We show that rDNA is replicated inside and outside the nucleolus where active transcription occurs at the same time. Nascent rDNA shows a maximum of nucleolar association during early S phase. In addition to EdU patterns typical for early or late S phase, two additional intermediate EdU profiles characteristic for mid S phase are described here. Moreover, the use of fas1 and fas1/2 reverted lines depleted of inactive copies allows for selective observation of the replication pattern of active rDNA. High-resolution data are presented revealing the culmination of replication in the mid S phase in the nucleolus and its vicinity. Together, our results provide a detailed snapshot of replication of active and inactive rDNA during S phase progression.