PMID- 28128408
OWN - NLM
STAT- MEDLINE
DCOM- 20170316
LR  - 20170316
IS  - 1676-5680 (Electronic)
IS  - 1676-5680 (Linking)
VI  - 16
IP  - 1
DP  - 2017 Jan 23
TI  - Dynamics of 45S rDNA sites in the cell cycle: fragile sites and chromosomal 
      stability in Lolium and Festuca.
LID - 10.4238/gmr16019156 [doi]
AB  - Analyses carried out with fluorescence in situ hybridization (FISH) in 
      C-metaphases of the Lolium-Festuca complex have shown the occurrence of 
      spontaneous fragile sites (FSs) in 45S rDNA regions. FSs are expressed as gaps 
      but they do not result in breaks or chromosomal fragments in these species. These 
      gaps have high DNA condensation observed as thin chromatin fibers that connect 
      the apparent segments of the fragile chromosome, allowing for genomic stability. 
      Assessing the behavior of these regions in the cell cycle of Lolium and Festuca 
      species may lead to a better understanding of the dynamics that preserve 
      stability during cell division. Furthermore, it is interesting to track the 
      dynamics of chromosomes bearing 45S rDNA sites in the cell cycle as well as to 
      observe the expression of FSs with no effect of the mitotic block. We observed 
      variation in both the number and size of 45S FISH signals from the S/G2 phases of 
      interphase and from prophase to anaphase where gaps in 45S rDNA sites also were 
      observed. The change in the degree of condensation of the 45S site begins in the 
      S/G2 phase and appears to be related to the transcriptional demand. Taking into 
      account that the number of 45S rDNA sites tends to be re-established when cells 
      reach telophase, we suggest that the chromatin fiber goes back to the normal 
      condensation level to the anaphase (after segregation), allowing for the 
      approximation of chromosome segments and ensuring dynamics that favor the genomic 
      stability of these species.
FAU - Rocha, L C
AU  - Rocha LC
AD  - Universidade Federal de Lavras, Departamento de Biologia, Lavras, MG, Brasil.
FAU - Silva, G A
AU  - Silva GA
AD  - Universidade Federal de Lavras, Departamento de Biologia, Lavras, MG, Brasil.
FAU - Bustamante, F O
AU  - Bustamante FO
AD  - Universidade Federal de Lavras, Departamento de Biologia, Lavras, MG, Brasil.
FAU - Silveira, R A D
AU  - Silveira RA
AD  - Universidade Federal de Lavras, Departamento de Biologia, Lavras, MG, Brasil.
FAU - Mittlemann, A
AU  - Mittlemann A
AD  - Embrapa Gado de Leite, Juiz de Fora, MG, Brasil.
AD  - Embrapa Clima Temperado, Pelotas, RS, Brasil.
FAU - Techio, V H
AU  - Techio VH
AD  - Universidade Federal de Lavras, Departamento de Biologia, Lavras, MG, Brasil 
      vhtechio@gmail.com.
LA  - eng
PT  - Journal Article
DEP - 20170123
PL  - Brazil
TA  - Genet Mol Res
JT  - Genetics and molecular research : GMR
JID - 101169387
RN  - 0 (RNA, Ribosomal)
RN  - 0 (RNA, ribosomal, 45S)
SB  - IM
MH  - Cell Cycle/*genetics
MH  - *Chromosomal Instability
MH  - *Chromosome Fragile Sites
MH  - Festuca/*genetics
MH  - Lolium/*genetics
MH  - RNA, Ribosomal/*genetics
EDAT- 2017/01/28 06:00
MHDA- 2017/03/17 06:00
CRDT- 2017/01/28 06:00
PHST- 2017/01/28 06:00 [entrez]
PHST- 2017/01/28 06:00 [pubmed]
PHST- 2017/03/17 06:00 [medline]
AID - gmr-16-01-gmr.16019156 [pii]
AID - 10.4238/gmr16019156 [doi]
PST - epublish
SO  - Genet Mol Res. 2017 Jan 23;16(1). doi: 10.4238/gmr16019156.