scholarly journals Three-dimensional organization of Drosophila melanogaster interphase nuclei. I. Tissue-specific aspects of polytene nuclear architecture.

1987 ◽  
Vol 104 (6) ◽  
pp. 1455-1470 ◽  
Author(s):  
M Hochstrasser ◽  
J W Sedat

Interphase chromosome organization in four different Drosophila melanogaster tissues, covering three to four levels of polyteny, has been analyzed. The results are based primarily on three-dimensional reconstructions from unfixed tissues using a computer-based data collection and modeling system. A characteristic organization of chromosomes in each cell type is observed, independent of polyteny, with some packing motifs common to several or all tissues and others tissue-specific. All chromosomes display a right-handed coiling chirality, despite large differences in size and degree of coiling. Conversely, in each cell type, the heterochromatic centromeric regions have a unique structure, tendency to associate, and intranuclear location. The organization of condensed nucleolar chromatin is also tissue-specific. The tightly coiled prothoracic gland chromosomes are arrayed in a similar fashion to the much larger salivary gland chromosomes described previously, having polarized orientations, nonintertwined spatial domains, and close packing of the arms of each autosome, whereas hindgut and especially the unusually straight midgut chromosomes display striking departures from these regularities. Surprisingly, gut chromosomes often appear to be broken in the centric heterochromatin. Severe deformations of midgut nuclei observed during gut contractions in living larvae may account for their unusual properties. Finally, morphometric measurements of chromosome and nuclear dimensions provide insights into chromosome growth and substructure and also suggest an unexpected parallel with diploid chromatin organization.

2015 ◽  
Vol 5 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Julianna Bozler ◽  
Huy Q Nguyen ◽  
Gregory C Rogers ◽  
Giovanni Bosco

Abstract Although the nuclear envelope is known primarily for its role as a boundary between the nucleus and cytoplasm in eukaryotes, it plays a vital and dynamic role in many cellular processes. Studies of nuclear structure have revealed tissue-specific changes in nuclear envelope architecture, suggesting that its three-dimensional structure contributes to its functionality. Despite the importance of the nuclear envelope, the factors that regulate and maintain nuclear envelope shape remain largely unexplored. The nuclear envelope makes extensive and dynamic interactions with the underlying chromatin. Given this inexorable link between chromatin and the nuclear envelope, it is possible that local and global chromatin organization reciprocally impact nuclear envelope form and function. In this study, we use Drosophila salivary glands to show that the three-dimensional structure of the nuclear envelope can be altered with condensin II-mediated chromatin condensation. Both naturally occurring and engineered chromatin-envelope interactions are sufficient to allow chromatin compaction forces to drive distortions of the nuclear envelope. Weakening of the nuclear lamina further enhanced envelope remodeling, suggesting that envelope structure is capable of counterbalancing chromatin compaction forces. Our experiments reveal that the nucleoplasmic reticulum is born of the nuclear envelope and remains dynamic in that they can be reabsorbed into the nuclear envelope. We propose a model where inner nuclear envelope-chromatin tethers allow interphase chromosome movements to change nuclear envelope morphology. Therefore, interphase chromatin compaction may be a normal mechanism that reorganizes nuclear architecture, while under pathological conditions, such as laminopathies, compaction forces may contribute to defects in nuclear morphology.


2021 ◽  
Author(s):  
Rashmi U Pathak ◽  
Rahul Sureka ◽  
Ashish Bihani ◽  
Parul Varma ◽  
Rakesh K Mishra

The study of Nuclear Matrix (NuMat) over the last 40 years has been limited to either isolated nuclei from tissues or cells grown in culture. Here, we provide a protocol for NuMat preparation in intact Drosophila melanogaster embryos and its use in dissecting the components of nuclear architecture. The protocol does not require isolation of nuclei and therefore maintains the three-dimensional milieu of an intact embryo, which is biologically more relevant compared to cells in culture. One of the advantages of this protocol is that only a small number of embryos are required. The protocol can be extended to larval tissues like salivary glands and imaginal discs with little modification. Taken together, it becomes possible to carry out such studies in parallel to genetic experiments using mutant and transgenic flies. This protocol, therefore, opens the powerful field of fly genetics to cell biology in the study of nuclear architecture.


2012 ◽  
Vol 2 (8) ◽  
pp. 873-882
Author(s):  
X. Hong ◽  
H. Doddapaneni ◽  
J. M. Comeron ◽  
M. J. Rodesch ◽  
H. A. Halvensleben ◽  
...  

2002 ◽  
Vol 76 (24) ◽  
pp. 12783-12791 ◽  
Author(s):  
Christopher R. Logg ◽  
Aki Logg ◽  
Robert J. Matusik ◽  
Bernard H. Bochner ◽  
Noriyuki Kasahara

ABSTRACT The inability of replication-defective viral vectors to efficiently transduce tumor cells in vivo has prevented the successful application of such vectors in gene therapy of cancer. To address the need for more efficient gene delivery systems, we have developed replication-competent retroviral (RCR) vectors based on murine leukemia virus (MLV). We have previously shown that such vectors are capable of transducing solid tumors in vivo with very high efficiency. While the natural requirement of MLV infection for cell division imparts a certain degree of specificity for tumor cells, additional means for confining RCR vector replication to tumor cells are desirable. Here, we investigated the parameters critical for successful tissue-specific transcriptional control of RCR vector replication by replacing various lengths of the MLV enhancer/promoter with sequences derived either from the highly prostate-specific probasin (PB) promoter or from a more potent synthetic variant of the PB promoter. We assessed the transcriptional specificity of the resulting hybrid long terminal repeats (LTRs) and the cell type specificity and efficiency of replication of vectors containing these LTRs. Incorporation of PB promoter sequences effectively restricted transcription from the LTR to prostate-derived cells and imparted prostate-specific RCR vector replication but required the stronger synthetic promoter and retention of native MLV sequences in the vicinity of the TATA box for optimal replicative efficiency and specificity. Our results have thus identified promoter strength and positioning within the LTR as important determinants for achieving both high transduction efficiency and strict cell type specificity in transcriptionally targeted RCR vectors.


2020 ◽  
Author(s):  
Didem P. Sarikaya ◽  
Katherine Rickelton ◽  
Julie M. Cridland ◽  
Ryan Hatmaker ◽  
Hayley K. Sheehy ◽  
...  

2010 ◽  
Vol 48 ◽  
pp. 1-24 ◽  
Author(s):  
Jan Postberg ◽  
Hans J. Lipps ◽  
Thomas Cremer

Understanding the evolutionary origin of the nucleus and its compartmentalized architecture provides a huge but, as expected, greatly rewarding challenge in the post-genomic era. We start this chapter with a survey of current hypotheses on the evolutionary origin of the cell nucleus. Thereafter, we provide an overview of evolutionarily conserved features of chromatin organization and arrangements, as well as topographical aspects of DNA replication and transcription, followed by a brief introduction of current models of nuclear architecture. In addition to features which may possibly apply to all eukaryotes, the evolutionary plasticity of higher-order nuclear organization is reflected by cell-type- and species-specific features, by the ability of nuclear architecture to adapt to specific environmental demands, as well as by the impact of aberrant nuclear organization on senescence and human disease. We conclude this chapter with a reflection on the necessity of interdisciplinary research strategies to map epigenomes in space and time.


PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18853 ◽  
Author(s):  
Ying Chen ◽  
Hongzheng Dai ◽  
Sidi Chen ◽  
Luoying Zhang ◽  
Manyuan Long

2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Anastasia Shpichka ◽  
Daria Osipova ◽  
Yuri Efremov ◽  
Polina Bikmulina ◽  
Nastasia Kosheleva ◽  
...  

For the past 10 years, the main efforts of most bioprinting research teams have focused on creating new bioinkformulations, rather than inventing new printing set-up concepts. New tissue-specific bioinks with good printability, shapefidelity, and biocompatibility are based on “old” (well-known) biomaterials, particularly fibrin. While the interest in fibrinbased bioinks is constantly growing, it is essential to provide a framework of material’s properties and trends. This review aimsto describe the fibrin properties and application in three-dimensional bioprinting and provide a view on further developmentof fibrin-based bioinks


2018 ◽  
Vol 217 (4) ◽  
pp. 1233-1248 ◽  
Author(s):  
Mustafa G. Aydogan ◽  
Alan Wainman ◽  
Saroj Saurya ◽  
Thomas L. Steinacker ◽  
Anna Caballe ◽  
...  

Centrioles are highly structured organelles whose size is remarkably consistent within any given cell type. New centrioles are born when Polo-like kinase 4 (Plk4) recruits Ana2/STIL and Sas-6 to the side of an existing “mother” centriole. These two proteins then assemble into a cartwheel, which grows outwards to form the structural core of a new daughter. Here, we show that in early Drosophila melanogaster embryos, daughter centrioles grow at a linear rate during early S-phase and abruptly stop growing when they reach their correct size in mid- to late S-phase. Unexpectedly, the cartwheel grows from its proximal end, and Plk4 determines both the rate and period of centriole growth: the more active the centriolar Plk4, the faster centrioles grow, but the faster centriolar Plk4 is inactivated and growth ceases. Thus, Plk4 functions as a homeostatic clock, establishing an inverse relationship between growth rate and period to ensure that daughter centrioles grow to the correct size.


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