scholarly journals Study of Long-Distance Functional Interactions between Su(Hw) Insulators That Can Regulate Enhancer-Promoter Communication in Drosophila melanogaster

2006 ◽  
Vol 26 (3) ◽  
pp. 754-761 ◽  
Author(s):  
Ekaterina Savitskaya ◽  
Larisa Melnikova ◽  
Margarita Kostuchenko ◽  
Elena Kravchenko ◽  
Ekaterina Pomerantseva ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Relevant Literature ◽  
Regulatory Elements ◽  
Large Set ◽  
Pairing Interaction ◽  
Long Distance ◽  
Control Of Gene Expression ◽  
Functional Interactions ◽  
Enhancer Blocking

ABSTRACT The Su(Hw) insulator found in the gypsy retrotransposon is the most potent enhancer blocker in Drosophila melanogaster. However, two such insulators in tandem do not prevent enhancer-promoter communication, apparently because of their pairing interaction that results in mutual neutralization. Furthering our studies of the role of insulators in the control of gene expression, here we present a functional analysis of a large set of transgenic constructs with various arrangements of regulatory elements, including two or three insulators. We demonstrate that their interplay can have quite different outcomes depending on the order of and distance between elements. Thus, insulators can interact with each other over considerable distances, across interposed enhancers or promoters and coding sequences, whereby enhancer blocking may be attenuated, cancelled, or restored. Some inferences concerning the possible modes of insulator action are made from collating the new data and the relevant literature, with tentative schemes illustrating the regulatory situations in particular model constructs.

The enhancer-blocking suppressor of Hairy-wing zinc finger protein of Drosophila melanogaster alters DNA structure

1994 ◽  
Vol 14 (9) ◽  
pp. 5645-5652
Author(s):  
B Shen ◽  
J Kim ◽  
D Dorsett
Keyword(s):  
Drosophila Melanogaster ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Dna Structure ◽  
Protein Domain ◽  
Transcription Activator ◽  
Long Distance ◽  
Dna Flexibility ◽  
Finger Protein ◽  
Enhancer Blocking

Insertion of the gypsy retrotransposon of Drosophila melanogaster into a gene control region can repress gene expression. The zinc finger protein (SUHW) encoded by the suppressor of Hairy-wing [su(Hw)] gene binds to gypsy and prevents gene enhancers from activating transcription. SUHW blocks an enhancer only when positioned between the enhancer and promoter. Although position dependent, SUHW enhancer blocking is distance independent. These properties indicate that SUHW does not interact with the transcription activator proteins that bind to enhancers. To explore if DNA distortions are involved in enhancer blocking, the ability of SUHW to alter DNA structure was examined in gel mobility assays. Indeed, SUHW induces an unusual change in the structure of the binding-site DNA. The change is not a directed DNA bend but correlates with loss of sequence-directed bends in the unbound DNA. The DNA distortion requires a SUHW protein domain not required for DNA binding, and mutant proteins that fail to alter DNA structure also fail to eliminate the sequence-directed bends. These results suggest that SUHW increases DNA flexibility. The DNA distortion is not sufficient to block enhancers, and therefore it is suggested that increased DNA flexibility may help SUHW interact and interfere with proteins that support long-distance enhancer-promoter interactions.

scholarly journals Cryptic Transcription and Early Termination in the Control of Gene Expression

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Jessie Colin ◽  
Domenico Libri ◽  
Odil Porrua
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Regulatory Function ◽  
Large Set ◽  
Control Of Gene Expression ◽  
Alternative Transcription ◽  
Cryptic Transcription ◽  
Nuclear Exosome ◽  
The Impact

Recent studies on yeast transcriptome have revealed the presence of a large set of RNA polymerase II transcripts mapping to intergenic and antisense regions or overlapping canonical genes. Most of these ncRNAs (ncRNAs) are subject to termination by the Nrd1-dependent pathway and rapid degradation by the nuclear exosome and have been dubbed cryptic unstable transcripts (CUTs). CUTs are often considered as by-products of transcriptional noise, but in an increasing number of cases they play a central role in the control of gene expression. Regulatory mechanisms involving expression of a CUT are diverse and include attenuation, transcriptional interference, and alternative transcription start site choice. This review focuses on the impact of cryptic transcription on gene expression, describes the role of the Nrd1-complex as the main actor in preventing nonfunctional and potentially harmful transcription, and details a few systems where expression of a CUT has an essential regulatory function. We also summarize the most recent studies concerning other types of ncRNAs and their possible role in regulation.

scholarly journals Chemoreceptivity of Drosophila melanogaster

1946 ◽  
Vol 133 (870) ◽  
pp. 1-19 ◽  
Keyword(s):  
Drosophila Melanogaster ◽  
Olfactory Response ◽  
Sensory Function ◽  
Main Role ◽  
Wild Type ◽  
Long Distance ◽  
Pit Organ ◽  
Chemical Stimuli ◽  
Thermal Stimuli

The occurrence of mutants of Drosophila melanogaster distinguished by the absence or structural modification of the antennae provides a means of assessing the role of the antennae with respect to the reception of various classes of stimuli. Antennaless ( A 0 ) phenotypes of antennaless stock fail to respond to those chemical stimuli which lead the fly to its food. Their temperature reactions are normal, and their humidity responses are opposite to those of somatically wild-type flies of the same stock or of wild-type controls. Aristapedia ( ss a ), which have leg-like antennae equipped with surface pegs and cones of supposed sensory function present in the normal antenna but absent in the normal leg, respond to chemical stimuli and humidity differences. As compared with that of normal flies, the olfactory response of aristapedia ( ss a ) is somewhat less intense, the humidity reaction being somewhat stronger. These mutants do not give the characteristic responses evoked by thermal stimuli both in normal flies and antennaless phenotypes. The outstanding histological differences between the structure of the antenna of aristapedia and that of wild-type flies is the absence of the pit organ. It thus seems that the pit organ is not essential to the olfactory response and plays no essential part in the humidity response. Since antennaless ( A 0 ) responds normally to thermal stimuli, none of the putative sense organs of the antennae are essential to the recognition of temperature differences, and since aristapedia ( ss a ) responds more weakly to chemical stimuli than do normal flies, the pit organs may well be long-distance chemoreceptors. What is more certain is that either the peg-like organs or the cones on the surface of the distal joint of the antennae or both are chemoreceptors. The same remark is equally applicable to the perception of humidity differences. Experiments here recorded do not justify the identification of the function of one or other type of sensilla with one or the other type of receptivity. While it is unjustifiable to exclude the possibility that short-distance chemical stimuli play a part in the attraction of flies of opposite sex, it appears that the main role of chemoreceptivity in relation to the mating behaviour of D. melanogaster is to ensure the aggregation of flies of both sexes in situations where food is available and sexual congress can be evoked by other forms of stimulation.

scholarly journals Role of Non-Coding Regulatory Elements in the Control of GR-Dependent Gene Expression

2021 ◽  
Vol 22 (8) ◽  
pp. 4258
Author(s):  
Malgorzata Borczyk ◽  
Mateusz Zieba ◽  
Michał Korostyński ◽  
Marcin Piechota
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Regulatory Elements ◽  
Transcription Activator ◽  
Long Distance ◽  
Core Promoters ◽  
Transcriptional Changes ◽  
Gene Expression Dynamics ◽  
Upregulated Genes

The glucocorticoid receptor (GR, also known as NR3C1) coordinates molecular responses to stress. It is a potent transcription activator and repressor that influences hundreds of genes. Enhancers are non-coding DNA regions outside of the core promoters that increase transcriptional activity via long-distance interactions. Active GR binds to pre-existing enhancer sites and recruits further factors, including EP300, a known transcriptional coactivator. However, it is not known how the timing of GR-binding-induced enhancer remodeling relates to transcriptional changes. Here we analyze data from the ENCODE project that provides ChIP-Seq and RNA-Seq data at distinct time points after dexamethasone exposure of human A549 epithelial-like cell line. This study aimed to investigate the temporal interplay between GR binding, enhancer remodeling, and gene expression. By investigating a single distal GR-binding site for each differentially upregulated gene, we show that transcriptional changes follow GR binding, and that the largest enhancer remodeling coincides in time with the highest gene expression changes. A detailed analysis of the time course showed that for upregulated genes, enhancer activation persists after gene expression changes settle. Moreover, genes with the largest change in EP300 binding showed the highest expression dynamics before the peak of EP300 recruitment. Overall, our results show that enhancer remodeling may not directly be driving gene expression dynamics but rather be a consequence of expression activation.

scholarly journals Mechanism and functional role of the interaction between CP190 and the architectural protein Pita in Drosophila melanogaster

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Marat Sabirov ◽  
Olga Kyrchanova ◽  
Galina V. Pokholkova ◽  
Artem Bonchuk ◽  
Natalia Klimenko ◽  
...  
Keyword(s):  
Regulatory Elements ◽  
Open Chromatin ◽  
Wild Type ◽  
Long Distance ◽  
Regulatory Domains ◽  
Time Interaction ◽  
Architectural Proteins

AbstractBackgroundPita is required for Drosophila development and binds specifically to a long motif in active promoters and insulators. Pita belongs to the Drosophila family of zinc-finger architectural proteins, which also includes Su(Hw) and the conserved among higher eukaryotes CTCF. The architectural proteins maintain the active state of regulatory elements and the long-distance interactions between them. In particular, Pita is involved in the formation of several boundaries between regulatory domains that controlled the expression of threehoxgenes in the Bithorax complex (BX-C). The CP190 protein is recruited to chromatin through interaction with the architectural proteins.ResultsUsing in vitro pull-down analysis, we precisely mapped two unstructured regions of Pita that interact with the BTB domain of CP190. Then we constructed transgenic lines expressing the Pita protein of thewild-typeand mutant variants lacking CP190-interacting regions. We have demonstrated that CP190-interacting region of the Pita can maintain nucleosome-free open chromatin and is critical for Pita-mediated enhancer blocking activity in BX-C. At the same time, interaction with CP190 is not required for the in vivo function of the mutant Pita protein, which binds to the same regions of the genome as the wild-type protein. Unexpectedly, we found that CP190 was still associated with the most of genome regions bound by the mutant Pita protein, which suggested that other architectural proteins were continuing to recruit CP190 to these regions.ConclusionsThe results directly demonstrate role of CP190 in insulation and support a model in which the regulatory elements are composed of combinations of binding sites that interact with several architectural proteins with similar functions.

scholarly journals The Role of Nationality in Ultra-Endurance Sports: The Paradigm of Cross-Country Skiing and Long-Distance Running

2020 ◽  
Vol 17 (7) ◽  
pp. 2543
Author(s):  
Beat Knechtle ◽  
Thomas Rosemann ◽  
Pantelis Theo Nikolaidis
Keyword(s):  
Relevant Literature ◽  
Marathon Running ◽  
Endurance Running ◽  
Long Distance ◽  
Endurance Sports ◽  
Long Distance Running ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Ultra Endurance

Although the variation of performance by nationality in endurance sports such as marathon has been well studied, little information exists so far on the role of nationality on performance in ultra-endurance sports. The aim of the present study was to review the role of nationality on cross-country skiing and ultra-endurance running. Scopus and PubMed were searched using the syntax “nationality AND (ultra-endurance OR ultra-marathon OR cross-country skiing) in 1/4/2020. This search identified 17 articles, whose references were further examined for relevant literature. It was observed that Russian athletes dominated ultra-endurance running and cross-country skiing races. It was shown that these races were in other countries, where it was assumed that only the best Russians competed. Potential explanations could be misuse of performance enhancing substances, historical, climate-geographical and psychophysiological (e.g., combination of genetic and social factors). In summary, recent studies found a dominance of Russian athletes in specific races (i.e., ‘Comrades Marathon’, ‘Vasaloppet’, and ‘Engadin Ski Marathon’) and disciplines (i.e., ultra-marathon running, cross-country skiing) over a period of several decades. Future studies are need to investigate other events and other sport disciplines to confirm this Russian dominance.

scholarly journals The enhancer-blocking suppressor of Hairy-wing zinc finger protein of Drosophila melanogaster alters DNA structure.

1994 ◽  
Vol 14 (9) ◽  
pp. 5645-5652 ◽  
Author(s):  
B Shen ◽  
J Kim ◽  
D Dorsett
Keyword(s):  
Drosophila Melanogaster ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Dna Structure ◽  
Protein Domain ◽  
Transcription Activator ◽  
Long Distance ◽  
Dna Flexibility ◽  
Finger Protein ◽  
Enhancer Blocking

Insertion of the gypsy retrotransposon of Drosophila melanogaster into a gene control region can repress gene expression. The zinc finger protein (SUHW) encoded by the suppressor of Hairy-wing [su(Hw)] gene binds to gypsy and prevents gene enhancers from activating transcription. SUHW blocks an enhancer only when positioned between the enhancer and promoter. Although position dependent, SUHW enhancer blocking is distance independent. These properties indicate that SUHW does not interact with the transcription activator proteins that bind to enhancers. To explore if DNA distortions are involved in enhancer blocking, the ability of SUHW to alter DNA structure was examined in gel mobility assays. Indeed, SUHW induces an unusual change in the structure of the binding-site DNA. The change is not a directed DNA bend but correlates with loss of sequence-directed bends in the unbound DNA. The DNA distortion requires a SUHW protein domain not required for DNA binding, and mutant proteins that fail to alter DNA structure also fail to eliminate the sequence-directed bends. These results suggest that SUHW increases DNA flexibility. The DNA distortion is not sufficient to block enhancers, and therefore it is suggested that increased DNA flexibility may help SUHW interact and interfere with proteins that support long-distance enhancer-promoter interactions.

scholarly journals Spatially regulated expression of retrovirus-like transposons during Drosophila melanogaster embryogenesis

1994 ◽  
Vol 64 (3) ◽  
pp. 167-181 ◽  
Author(s):  
Dali Ding ◽  
Howard D. Lipshitz
Keyword(s):  
Drosophila Melanogaster ◽  
Expression Patterns ◽  
Regulatory Elements ◽  
Host Gene ◽  
Regulatory Sequences ◽  
Wild Type ◽  
Control Of Gene Expression ◽  
Spatial Expression ◽  
Regulated Expression ◽  
Type Strains

SummaryOver twenty distinct families of long terminal direct repeat (LTR)-containing retrotransposons have been identified in Drosophila melanogaster. While there have been extensive analyses of retrotransposon transcription in cultured cells, there have been few studies of the spatial expression of retrotransposons during normal development. Here we report a detailed analysis of the spatial expression patterns of fifteen families of retrotransposons during Drosophila melanogaster embryogenesis (17.6, 297, 412, 1731, 3S18, blood, copia, gypsy, HMS Beagle, Kermit/flea, mdg1, mdg3, opus, roo/B104 and springer). In each case, analyses were carried out in from two to four wild-type strains. Since the chromosomal insertion sites of any particular family of retrotransposons vary widely among wild-type strains, a spatial expression pattern that is conserved among strains is likely to have been generated through interaction of host transcription factors with cis-regulatory elements resident in the retrotransposons themselves. All fifteen families of retrotransposons showed conserved patterns of spatially and temporally regulated expression during embryogenesis. These results suggest that all families of retrotransposons carry cis-acting elements that control their spatial and temporal expression patterns. Thus, transposition of a retrotransposon into or near a particular host gene-possibly followed by an excision event leaving behind the retrotransposon's cis-regulatory sequences-might impose novel developmental control on such a host gene. Such a mechanism would serve to confer evolutionarily significant alterations in the spatio-temporal control of gene expression.

Attachment Styles, Physical Proximity, and Relational Satisfaction

2014 ◽  
Vol 4 (2) ◽  
pp. 106-112
Author(s):  
Anita Shrivastava ◽  
Andrea Burianova
Keyword(s):  
Attachment Styles ◽  
Romantic Relationship ◽  
Distinct Type ◽  
Relational Satisfaction ◽  
Long Distance ◽  
Avoidant Attachment ◽  
Geographic Separation ◽  
Relationship Of ◽  
Attachment Dimensions

This study aimed to explore the relationships between attachment styles, proximity, and relational satisfaction. This was achieved by assessing a distinct type of long distance romantic relationship of flying crews, compared with proximal (non-flying crew) romantic relationships. The responses of 139 expatriate professionals revealed significant associations between proximity and anxious and avoidant attachment dimensions. The role of the avoidant dimension in comparison with that of the anxious dimension was found to be a significant predictor of relational satisfaction. This study contributes significantly toward addressing the role of proximity and attachment in relational satisfaction in a new context of geographic separation.

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