Temporal and spatial coordination of chromosome movement, spindle formation, and nuclear envelope breakdown during prometaphase in Drosophila melanogaster embryos.

Hiraoka, Yasushi; Agard, David A.; Sedat, John W.

doi:10.1083/jcb.111.6.2815

Cited by 99 publications

(72 citation statements)

References 64 publications

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“…We observed a polarized foci distribution in the nucleus, consistent with Rabl configuration (Hiraoka et al 1990). This is shown in the representative panels in Figure 1B.…”

Section: Resultssupporting

confidence: 84%

“…At this stage the nuclei progress synchronously through the cell cycle within a monolayer at the embryo periphery, providing a perfect milieu for imaging of nuclear dynamics. We found that during interphase in the embryo, the 16 telomeres clustered into four to six foci in a polarized manner that is consistent with previously reported Rabl organization of the nucleus (Hiraoka et al 1990). We found that telomere clusters exhibited doubling of HOAP intensity during interphase-dynamics that could be indicative of protein loading.…”

supporting

confidence: 91%

“…Most of the telomeres of the other chromosomes are situated at the ends of long chromosomal arms and reach down to the bottom of the nucleus where they would cluster in two to four foci, leaving the middle devoid of foci. The model is drawn to suggest that the telomeres of each chromosome (and its homolog) cluster among each other ( Figure 1B), as proposed previously (Hiraoka et al 1990). …”

Section: Resultsmentioning

confidence: 71%

“…Telomere clustering is not mediated by homolog pairing: It has been previously suggested that the telomeres of homologs interact with each other in syncytial blastoderm embryos (Hiraoka et al 1990). Despite the fact that Figure 2 Telomere signal throughout the cell cycle.…”

Section: Different Mechanisms Governing Telomere Clusteringmentioning

confidence: 99%

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Clustering and Protein Dynamics ofDrosophila melanogasterTelomeres

2013

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Telomeres are obligatory chromosomal landmarks that demarcate the ends of linear chromosomes to distinguish them from broken ends and can also serve to organize the genome. In both budding and fission yeast, they cluster at the periphery of the nucleus, potentially to establish a compartment of silent chromatin. To gain insight into telomere organization in higher organisms, we investigated their distribution in interphase nuclei of Drosophila melanogaster. We focused on the syncytial blastoderm, an excellent developmental stage for live imaging due to the synchronous division of the nuclei at this time. We followed the EGFP-labeled telomeric protein HOAP in vivo and found that the 16 telomeres yield four to six foci per nucleus, indicative of clustering. Furthermore, we confirmed clustering in other somatic tissues. Importantly, we observed that HOAP signal intensity in the clusters increases in interphase, potentially due to loading of HOAP to newly replicated telomeres. To determine the rules governing clustering, we used in vivo imaging and fluorescence in situ hybridization to test several predictions. First, we inspected mutant embryos that develop as haploids and found that clustering is not mediated by associations between homologs. Second, we probed specifically for a telomere of novel sequence and found strong evidence against DNA sequence identity and homology as critical factors. Third, we ruled out predominance of intrachromosomal interactions by marking both ends of a chromosome. Based on these results, we propose that clustering is independent of sequence and is likely maintained by an as yet undetermined factor.

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“…We observed a polarized foci distribution in the nucleus, consistent with Rabl configuration (Hiraoka et al 1990). This is shown in the representative panels in Figure 1B.…”

Section: Resultssupporting

confidence: 84%

supporting

confidence: 91%

Section: Resultsmentioning

confidence: 71%

Section: Different Mechanisms Governing Telomere Clusteringmentioning

confidence: 99%

See 2 more Smart Citations

Clustering and Protein Dynamics ofDrosophila melanogasterTelomeres

2013

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“…Cremer et al (1993) suggested that gene-rich and early-replicating chromatin is systematically organized so that it is readily accessible to the transcription and replication machinery. Using elegant optical techniques, Sedat and coworkers demonstrated a systematic arrangement of Drosophila prometaphasic chromosomes, with telomeres and centromeres located at opposite nuclear poles (Hiraoka et al, 1990a). It is not clear, however, whether these observations apply to mammalian cells.…”

mentioning

confidence: 99%

Evidence for the organization of chromatin in megabase pair-sized loops arranged along a random walk path in the human G0/G1 interphase nucleus.

Yokota

Engh

Hearst

et al. 1995

The Journal of Cell Biology

271

200

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Abstract. We determined the folding of chromosomes in interphase nuclei by measuring the distance between points on the same chromosome. Over 25,000 measurements were made in G0/G1 nuclei between DNA sequences separated by 0.15-190 megabase pairs (Mbp) on three human chromosomes. The DNA sequences were specifically labeled by fluorescence in situ hybridization. The relationship between mean-square interphase distance and genomic separation has two linear phases, with a transition at N2 Mbp. This biphasic relationship indicates the existence of two organizational levels at scales >100 kbp. On one level, chromatin appears to be arranged in large loops several Mbp in size. Within each loop, chromatin is randomly folded. On the second level, specific loop-attachment sites are arranged to form a supple, backbonelike structure, which also shows characteristic random walk behavior. This random walk/giant loop model is the simplest model that fully describes the observed large-scale spatial relationships. Additional evidence for large loops comes from measurements among probes in Xq28, where interphase distance increases and then locally decreases with increasing genomic separation. SIaORXLY after cell division, the mitotic chromosomes decondense and diffuse into the interphase nucleus. While individual chromosomes cannot be discerned, important processes related to chromosome function take place. Regulatory factors interact with chromatin, DNA is made accessible for transcription, RNA is produced and processed, DNA is replicated, and repairs are made of DNA strand breaks. When the chromosomes reappear for the next mitosis, they have been duplicated and prepared for rapid partitioning over the daughter cells. The complexity of these processes raises many questions about the large-scale organization of chromosomes and how this organization relates to cell function (e.g., Blobel, 1985;Manuelidis and Chen, 1990;Cook, 1991;Lawrence and Singer, 1991;De Boni, 1994).Diverse models, ranging from highly random to highly organized, have been proposed for the higher-order organization of interphase chromatin. These models variously involve irregularly folded fibers (DuPraw, 1965), radial loop structures (Manuelidis and Chen, 1990), giant loops (Ostashevsky and Lange, 1994), semirigid orientation ("Rabl" configuration) (Rabl, 1885;Comings, 1968), or random polymers confined by tethering or external forces (Hahnfeldt et al., 1993). Some models assign to chromo-

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Dynamic remodeling of nuclear architecture during the cell cycle

Johansen

1996

J. Cell. Biochem.

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The nuclear matrix is an integral part of nuclear structure which undergoes a profound reorganization during the cell cycle reflecting major changes in functional requirements. This includes the processes of DNA replication and gene expression at interphase and partitioning of the nuclear contents during mitosis. Using a monoclonal antibody (mAb2A) which specifically stains a novel nuclear meshwork which reorganizes during the cell cycle in Drosophila, we have initiated a study to: 1) more closely analyze this structural reorganization; 2) clone and characterize the antigens recognized by this antibody; and 3) isolate other interacting proteins in order to gain insight into the regulation of this process. The mAb2A-labeled structure changes from what appears as a diffuse meshwork at interphase to a distinct spindle-like scaffold at prophase. Since at metaphase the microtubules of the mitotic apparatus co-localize with the mAb2A spindle structure, a model is considered whereby the nuclear mAb2A-labeled scaffolding reorganizes during the cell cycle to provide a guide for the establishment of the mitotic apparatus. The mAb2A has identified two separate antigens, each of which shows similar distribution patterns. One of these antigens has been partially cloned and contains an unusual tandem ser-thr kinase domain. The association of this kinase homologue with a nuclear scaffold which reorganizes during the cell cycle suggests that it may be involved in regulating changes in nuclear architecture during the cell cycle and/or in mediating the downstream consequences of such changes.

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Temporal and spatial coordination of chromosome movement, spindle formation, and nuclear envelope breakdown during prometaphase in Drosophila melanogaster embryos.

Cited by 99 publications

References 64 publications

Clustering and Protein Dynamics ofDrosophila melanogasterTelomeres

Clustering and Protein Dynamics ofDrosophila melanogasterTelomeres

Evidence for the organization of chromatin in megabase pair-sized loops arranged along a random walk path in the human G0/G1 interphase nucleus.

Dynamic remodeling of nuclear architecture during the cell cycle

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