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Chromatin associations in Arabidopsis interphase nuclei.

Schubert V, Rudnik R, Schubert I - Front Genet (2014)

Bottom Line: We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances.The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns.Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben Stadt Seeland, Germany.

ABSTRACT
The arrangement of chromatin within interphase nuclei seems to be caused by topological constraints and related to gene expression depending on tissue and developmental stage. In yeast and animals it was found that homologous and heterologous chromatin association are required to realize faithful expression and DNA repair. To test whether such associations are present in plants we analyzed Arabidopsis thaliana interphase nuclei by FISH using probes from different chromosomes. We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances. The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns. Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus. Nevertheless, chromatin movement enables a flexible spatial genome arrangement in plant nuclei.

No MeSH data available.


Related in: MedlinePlus

~85 kb euchromatin segments may loop out from their CTs. (A) Scheme of chromosome 1 showing the labeling of CT1top arm, and BAC T2P11 therein in different color as used for FISH. (B) Examples of chromatin configurations in 4C, 32C, and 64C nuclei. Sister chromatid territories of one (asterisks) or both (cross) homologs may be separated due to missing chromosome arm cohesion. The T2P11 segment is associated with (triangle) or separated from its CT (arrows). The strongly elongated 4C nucleus shows the T2P11 segment absent from the left CT and moved into the homologous right CT.
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Figure 2: ~85 kb euchromatin segments may loop out from their CTs. (A) Scheme of chromosome 1 showing the labeling of CT1top arm, and BAC T2P11 therein in different color as used for FISH. (B) Examples of chromatin configurations in 4C, 32C, and 64C nuclei. Sister chromatid territories of one (asterisks) or both (cross) homologs may be separated due to missing chromosome arm cohesion. The T2P11 segment is associated with (triangle) or separated from its CT (arrows). The strongly elongated 4C nucleus shows the T2P11 segment absent from the left CT and moved into the homologous right CT.

Mentions: In ~13% of 4C nuclei an interstitial ~85 kb euchromatin segment cloned in BAC T2P11 was localized outside of its CT (Pecinka et al., 2004). This segment may also loop out in nuclei of higher ploidy levels of 32C and 64C. In addition, due to chromatin fiber elongation and distant movements the segment may appear aside from its CT while the homologous segment is present in its CT (once observed in 150 nuclei analyzed) (Figure 2).


Chromatin associations in Arabidopsis interphase nuclei.

Schubert V, Rudnik R, Schubert I - Front Genet (2014)

~85 kb euchromatin segments may loop out from their CTs. (A) Scheme of chromosome 1 showing the labeling of CT1top arm, and BAC T2P11 therein in different color as used for FISH. (B) Examples of chromatin configurations in 4C, 32C, and 64C nuclei. Sister chromatid territories of one (asterisks) or both (cross) homologs may be separated due to missing chromosome arm cohesion. The T2P11 segment is associated with (triangle) or separated from its CT (arrows). The strongly elongated 4C nucleus shows the T2P11 segment absent from the left CT and moved into the homologous right CT.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230181&req=5

Figure 2: ~85 kb euchromatin segments may loop out from their CTs. (A) Scheme of chromosome 1 showing the labeling of CT1top arm, and BAC T2P11 therein in different color as used for FISH. (B) Examples of chromatin configurations in 4C, 32C, and 64C nuclei. Sister chromatid territories of one (asterisks) or both (cross) homologs may be separated due to missing chromosome arm cohesion. The T2P11 segment is associated with (triangle) or separated from its CT (arrows). The strongly elongated 4C nucleus shows the T2P11 segment absent from the left CT and moved into the homologous right CT.
Mentions: In ~13% of 4C nuclei an interstitial ~85 kb euchromatin segment cloned in BAC T2P11 was localized outside of its CT (Pecinka et al., 2004). This segment may also loop out in nuclei of higher ploidy levels of 32C and 64C. In addition, due to chromatin fiber elongation and distant movements the segment may appear aside from its CT while the homologous segment is present in its CT (once observed in 150 nuclei analyzed) (Figure 2).

Bottom Line: We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances.The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns.Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus.

View Article: PubMed Central - PubMed

Affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben Stadt Seeland, Germany.

ABSTRACT
The arrangement of chromatin within interphase nuclei seems to be caused by topological constraints and related to gene expression depending on tissue and developmental stage. In yeast and animals it was found that homologous and heterologous chromatin association are required to realize faithful expression and DNA repair. To test whether such associations are present in plants we analyzed Arabidopsis thaliana interphase nuclei by FISH using probes from different chromosomes. We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances. The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns. Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus. Nevertheless, chromatin movement enables a flexible spatial genome arrangement in plant nuclei.

No MeSH data available.


Related in: MedlinePlus