rRNA	Ribosomal ribonucleic acid
rDNA	Ribosomal deoxyribonucleic acid
HR	Homologous recombination
S-type	Separated type
L-type	Linked type
RNA Pol I	RNA polymerase I
RNA Pol III	RNA polymerase III
Col-0	Columbia-0
NOR	Nucleolus-organizing region
VAR	Variant
ITS	Internal transcribed spacer
ETS	External transcribed spacer
IGS	Intergenic spacer
NTS	Non-transcribed spacer
GP	Gene promoter
SP	Spacer promoter
siRNA	Small interfering ribonucleic acid
FISH	Fluorescence in situ hybridization
EDF-FISH	Extended DNA fiber fluorescence in situ hybridization
PCR	Polymerase chain reaction
ORC	Origin recognition complex
ERC	Extrachromosomal rDNA circle
RFB	Replication fork barrier
DSB	Double-strand break
Fob1p	Fork blocking less protein
Sir2p	Silent information regulator 2 protein
WRN	Werner syndrome helicase
BLM	Bloom syndrome helicase
CSB	Cockayne syndrome group B protein
ATM	Ataxia telangiectasia mutated kinase
G4	Guanine quadruplex
CAF-1	Chromatin assembly factor 1
FAS1/FAS2	Fasciata 1/Fasciata 2
MSI1	Multicopy suppressor of IRA 1
CAC1-3	Chromatin assembly complex 1-3
ASF1	Anti-silencing factor 1
NER	Nucleotide excision repair
HDR	Homology-dependent DNA damage repair
SSA	Single-strand annealing
WT	Wild type
NAP1	Nucleosome assembly protein 1
SIM	Structure illumination microscopy
XRCC2/3	X-ray repair cross-complementing protein 2/3
MMS	Methyl methanesulfonate
RTEL1	Regulator of telomere length 1
PCNA	Proliferating cell nuclear antigen