scholarly journals cis-Acting Site Controlling Bidirectional Transcription at the Growth-Differentiation Transition in Dictyostelium discoideum

2006 ◽  
Vol 5 (7) ◽  
pp. 1104-1110 ◽  
Author(s):  
Shigenori Hirose ◽  
Samuel H. Payne ◽  
William F. Loomis
Keyword(s):  
Transcription Factors ◽  
Life Cycle ◽  
Dictyostelium Discoideum ◽  
Critical Region ◽  
Cis Acting ◽  
Bidirectional Transcription ◽  
The Right

ABSTRACT A pair of adjacent genes, impA and dia1, are divergently transcribed but expressed at different stages in the life cycle of Dictyostelium discoideum. The intervening 654-bp region carries cis-acting regions that are essential for transcription in both directions as well as repression of dia1 in growing cells. We have focused on a 112-bp region proximal to dia1 that is essential for bidirectional transcription. Analyses of a set of internal deletions showed that the sequence between positions 80 and 97 (TTTGAATTTTTTGAATTT) is critical and that bases outside this region are dispensable. Site-directed mutations within this critical region confirmed the importance of this sequence for transcription both to the right and to the left. However, insertions of either 6 or 24 Ts into the run of 6 Ts separating the repeated GAA sequence had little effect on the functioning of the site in either direction, suggesting that factors recognize the half-sites TTGAATT separately. Inversion of the bases between positions 80 and 97 greatly reduced expression in both directions, indicating that orientation is critical for expression of both the nearby impA gene and the distal dia1 gene, which is more than 500 bp away. Comparison of 38 mutant constructs with multiple random variations in the region indicated that transcription factors may bind to a range of related sequences and still retain function. All functional constructs directed transcription both leftward and rightward, while all nonfunctional constructs were impaired for transcription in both directions. It appears that the same transcription complex controls transcription of both impA and dia1.

MODELS FOR DESCRIBING AND SUPPORTING AUTOMATED SYSTEM SCENARIOS

2020 ◽  
pp. 18-22
Author(s):  
В.П. Хранилов ◽  
П.В. Мисевич ◽  
А.Э. Ермилов
Keyword(s):  
Fuzzy Logic ◽  
Life Cycle ◽  
Automated System ◽  
Just In Time ◽  
Success Factor ◽  
Situational Analysis ◽  
Frame Model ◽  
Information Logistics ◽  
The Right ◽  
The Mathematical Model

В статье представлены модели описания сценариев функционирования автоматизированных систем (АС). Вводится и анализируется категория "жизненный цикл сценариев АС". Наиболее важными этапами жизненного цикла сценария являются следующие: этап формирования событийного набора для формирования сценария, этап выполнения последовательности сценарных событий и этап ситуационного анализа внешней и внутренней среды события. В статье предложена математическая модель функционирования АС, которая используется для поддержки этапа выполнения последовательности сценарных событий и основана на принципе информационной логистики: каждый параметр (набор данных) находится в нужном месте в АС, "точно в срок" и в нужном формате. Для поддержки ситуационного анализа предлагается модифицированная фреймовая модель. Ситуационный анализ используется для разработки алгоритмов событий и определения следующего события в сценарии. Модифицированная фреймовая модель основана на использовании нечетких логических процедур в фреймовой сети. The paper presents models for describing the operating scenarios of automated systems. The authors introduce and analyze the category “the life cycle of automated system scenarios”. The life cycle consists of a sequence of stages. The leading success factor of any scenario is the support of the scenario during all stages of its life cycle. The most important stages of the scenario life cycle are the following: the stage of forming the event set for generating the scenario, the stage of performing the sequence of scenario events and the stage of situational analysis of the external and internal environment of the event. In the article it is proposed to use a theoretical set model in order to select an element from a set of alternatives. The elements are events for designing a scenario. The model uses fuzzy logic and is based on the process of controlling an array of parameters if variants are available. The model is used to support the stage of forming a set of events for generating the scenario. The mathematical model of automated system operation which is used to support the stage of performing the sequence of scenario events is suggested in the article. The model is based on the principle of information logistics: each parameter (a set of data) is in the right place in the automated system, ‘just-in-time’ and in the required format. A modified frame model is proposed to support situational analysis. The situational analysis is used to operate the event algorithms and to determine the next event in the scenario. The modified frame model is based on the use of fuzzy logic procedures in a frame network.

scholarly journals How Cardiac Embryology Translates into Clinical Arrhythmias

2021 ◽  
Vol 8 (6) ◽  
pp. 70
Author(s):  
Mathilde R. Rivaud ◽  
Michiel Blok ◽  
Monique R. M. Jongbloed ◽  
Bastiaan J. Boukens
Keyword(s):  
Transcription Factors ◽  
Association Studies ◽  
Pulmonary Veins ◽  
Atrioventricular Node ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Congenital Atrioventricular Block ◽  
The Right

The electrophysiological signatures of the myocardium in cardiac structures, such as the atrioventricular node, pulmonary veins or the right ventricular outflow tract, are established during development by the spatial and temporal expression of transcription factors that guide expression of specific ion channels. Genome-wide association studies have shown that small variations in genetic regions are key to the expression of these transcription factors and thereby modulate the electrical function of the heart. Moreover, mutations in these factors are found in arrhythmogenic pathologies such as congenital atrioventricular block, as well as in specific forms of atrial fibrillation and ventricular tachycardia. In this review, we discuss the developmental origin of distinct electrophysiological structures in the heart and their involvement in cardiac arrhythmias.

scholarly journals A common cis-acting sequence in the DiGeorge critical region regulates bi-directional transcription of UFD1L and CDC45L

2001 ◽  
Vol 108 (1-2) ◽  
pp. 81-92 ◽  
Author(s):  
Amit Kunte ◽  
Kathryn Ivey ◽  
Chihiro Yamagishi ◽  
Vidu Garg ◽  
Hiroyuki Yamagishi ◽  
...  
Keyword(s):  
Critical Region ◽  
Cis Acting

Synergistic interactions between transcription factors control expression of the apolipoprotein AI gene in liver cells

1991 ◽  
Vol 11 (2) ◽  
pp. 677-687
Author(s):  
R L Widom ◽  
J A Ladias ◽  
S Kouidou ◽  
S K Karathanasis
Keyword(s):  
Transcription Factors ◽  
Hepg2 Cells ◽  
Liver Cells ◽  
Site Directed Mutagenesis ◽  
Apolipoprotein Ai ◽  
Transcriptional Enhancer ◽  
Specific Expression ◽  
Cis Acting ◽  
Synergistic Interactions ◽  
Gene Coding

The gene coding for apolipoprotein AI (apoAI), a plasma protein involved in the transport of cholesterol and other lipids in the plasma, is expressed predominantly in liver and intestine. Previous work in our laboratory has shown that different cis-acting elements in the 5'-flanking region of the human apoAI gene control its expression in human hepatoma (HepG2) and colon carcinoma (Caco-2) cells. Hepatocyte-specific expression is mediated by elements within the -256 to -41 DNA region relative to the apoAI gene transcription start site (+1). In this study it was found that the -222 to -110 apoAI gene region is necessary and sufficient for expression in HepG2 cells. It was also found that this DNA region functions as a powerful hepatocyte-specific transcriptional enhancer. Gel retardation and DNase I protection experiments showed that HepG2 cells contain proteins that bind to specific sites, sites A (-214 to -192), B (-169 to -146), and C (-134 to -119), within this enhancer. Site-directed mutagenesis that prevents binding of these proteins to individual or different combinations of these sites followed by functional analysis of these mutants in HepG2 cells revealed that protein binding to any one of these sites in the absence of binding to the others was not sufficient for expression. Binding to any two of these sites in any combination was sufficient for only low levels of expression. Binding to all three sites was essential for maximal expression. These results indicate that the transcriptional activity of the apoAI gene in liver cells is dependent on synergistic interactions between transcription factors bound to its enhancer.

Reconstitution of the vitamin D-responsive osteocalcin transcription unit in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (8) ◽  
pp. 3517-3523
Author(s):  
D P McDonnell ◽  
J W Pike ◽  
D J Drutz ◽  
T R Butt ◽  
B W O'Malley
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Vitamin D ◽  
Transcription Factors ◽  
Promoter Activity ◽  
Transcription Unit ◽  
Proximal Promoter ◽  
Regulatory Sequences ◽  
Cis Acting ◽  
Osteocalcin Gene ◽  
Definition Of

The human osteocalcin gene is regulated in mammalian osteoblasts by 1,25(OH)2D3-dependent and -independent mechanisms. The sequences responsible for this activity have been mapped to within the -1339 region of the gene. We show here that this enhancer region functions analogously in Saccharomyces cerevisiae cells engineered to produce active 1,25(OH)2D3 receptor. When fused to the proximal promoter elements of the yeast iso-1-cytochrome c gene, the enhancer demonstrated substantial promoter activity. This activity was elevated further by 1,25(OH)2D3 when the reporter constructs were assayed in cells containing the 1,25(OH)2D3 receptor. This system affords a model for 1,25(OH)2D3 action and represents a simple assay system that will enable definition of the important cis-acting regulatory sequences within the osteocalcin gene and identification of their cognate transcription factors.

Internally located and oppositely oriented polymerase II promoters direct convergent transcription of a LINE-like retroelement, the Dictyostelium repetitive element, from Dictyostelium discoideum

1994 ◽  
Vol 14 (5) ◽  
pp. 3074-3084
Author(s):  
G Schumann ◽  
I Zündorf ◽  
J Hofmann ◽  
R Marschalek ◽  
T Dingermann
Keyword(s):  
Dictyostelium Discoideum ◽  
Repetitive Element ◽  
Building Blocks ◽  
Rna Transcripts ◽  
Convergent Transcription ◽  
Sense Strand ◽  
Cloned Cdna ◽  
Dna Strand ◽  
The Right ◽  
Complementary Sense

The Dictyostelium discoideum NC4 genome harbors approximately 150 individual copies of a retrotransposable element called the Dictyostelium repetitive element (DRE). This element contains nonidentical terminal repeats (TRs) consisting of conserved building blocks A and B in the left TR and B and C in the right TR. Seven different-sized classes of RNA transcripts from these elements were resolved by Northern (RNA) blot analysis, but their combined abundance was very low. When D. discoideum cells were grown in the presence of the respiratory chain blocker antimycin A, steady-state concentrations of these RNA species increased 10- to 20-fold. The D. discoideum genome contains two DRE subtypes, the full-length 5.7-kb DREa and the internally deleted 2.4-kb DREb. Both subtypes are transcribed, as confirmed by analysis of cloned cDNA. Primary transcripts from the sense strand originate at nucleotide +1 and terminate at two dominant sites, located 21 or 28 nucleotides upstream from the 3' end of the elements. The activity of a reasonably strong polymerase II promoter in the 5'-terminal A module is slightly upregulated by the tRNA gene located 50 +/- 4 nucleotides upstream and drastically reduced by the adjacent B module of the DRE. Transcripts from the opposite DNA strand (complementary-sense transcripts) were also detected, directed by an internally located polymerase II promoter residing within the C module. This latter transcription was initiated at multiple sites within the oligo(dA12) stretch which terminates DREs.

Identification of a signal transduction response sequence element necessary for induction of a Dictyostelium discoideum gene by extracellular cyclic AMP

1989 ◽  
Vol 9 (11) ◽  
pp. 4660-4669
Author(s):  
J Pavlovic ◽  
B Haribabu ◽  
R P Dottin
Keyword(s):  
Signal Transduction ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Regulatory Element ◽  
Response Sequence ◽  
Base Pairs ◽  
Camp Response Element ◽  
Sequence Element ◽  
Cis Acting ◽  
Gene Coding

The signal transduction pathways that lead to gene induction are being intensively investigated in Dictyostelium discoideum. We have identified by deletion and transformation analysis a sequence element necessary for induction of a gene coding for uridine diphosphoglucose pyrophosphorylase (UDPGP1) of D. discoideum in response to extracellular cyclic AMP (cAMP). This regulatory element is located 380 base pairs upstream of the transcription start site and contains a G+C-rich partially palindromic sequence. It is not required for transcription per se but is required for induction of the gene in response to the stimulus of extracellular cAMP. The cAMP response sequence is also required for induction of the gene during normal development. A second A+T-rich cis-acting region located immediately downstream of the cAMP response sequence appears to be essential for the basal level of expression of the UDPGP1 gene. The position of the cAMP response element coincides with a DNase I-hypersensitive site that is observed when the UDPGP1 gene is actively transcribed.

scholarly journals Infestations Myxobolus sp. in Gills Koi (Cyprinus carpio) That No Clinical Symptoms

2020 ◽  
Vol 11 (1) ◽  
pp. 20-25
Author(s):  
Zulkifli ◽  
Novia Christi Prihartini
Keyword(s):  
Water Quality ◽  
Life Cycle ◽  
Clinical Symptoms ◽  
Water Quality Management ◽  
Ornamental Fish ◽  
Parasitic Diseases ◽  
North Sulawesi ◽  
Ornamental Fish Trade ◽  
The Right ◽  
Fish Trade

Ornamental fish trade between regions in Indonesia allows the transfer of disease, especially if the disease does not show clinical symptoms in fish traded. Koi fish in Tahuna, North Sulawesi, mostly come from the area of ​​East Java, which is one area with many cases of myxobolusis. In addition, the potential for parasitic diseases that come along when koi fish are brought between areas cannot be avoided, because the examination of parasites, especially Myxobolus sp. no longer listed in the regulation as a quarantine inspection requirement. The purpose of this study was to see the Myxobolus sp infestation that infected koi in Tahuna, North Sulawesi, although there were no clinical symptoms using conventional techniques and histopathology. The results of the examination showed Myxobolus spore infestation on the gills of the koi, although the amount was not much, both conventional and histopathological techniques. This shows that our level of awareness of the types of parasites that can infect fish is still lacking. Myxobolus sp is only transmitted through the spore stage back and forth; there is no horizontal or vertical transmission in fish or tubifex T worm populations. More knowledge regarding the life cycle of the Myxobolus sp. in order to obtain the right handling to deal with outbreaks, especially water quality management at the location of the cultivation.

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