Transcriptional properties of BmX, a moderately repetitive silkworm gene that is an RNA polymerase III template

1988 ◽  
Vol 8 (2) ◽  
pp. 624-631
Author(s):  
E T Wilson ◽  
D P Condliffe ◽  
K U Sprague
Keyword(s):  
Control Region ◽  
Transcription Initiation ◽  
Rna Polymerase Iii ◽  
Sequence Element ◽  
Direct Transcription ◽  
Factor Binding ◽  
Large Gene ◽  
Polymerase Iii ◽  
Downstream Control

We analyzed the transcriptional properties of a repetitive sequence element, BmX, that belongs to a large gene family (approximately 2 x 10(4) copies) in the genome of the Bombyx mori silkworm. We discovered BmX elements because of their ability to direct transcription by polymerase III in vitro and used them to test the generality of the properties of previously identified silkworm polymerase III control elements. We found that the signals that act in cis to control BmX transcription strongly resemble those that direct transcription of other silkworm polymerase III templates. As with silkworm tRNA and 5S RNA genes, transcription of BmX requires sequence signals located both upstream and downstream from the site of transcription initiation. The critical upstream sequences are structurally as well as functionally similar in the three kinds of templates. The downstream control region of BmX resembles the corresponding part of a silkworm alanine tRNA gene in that it provides a large (greater than 100 base pairs) region that influences transcription factor binding. Moreover, the factor-binding regions of both tRNA(Ala) and BmX genes are remarkable in that under certain conditions, key elements within them (the B boxes, for example) appear dispensable. This behavior can be understood if, in both of these templates, the downstream control region acts as a large target for interaction with a multifactor complex.

Numerical simulation of flow over a square cylinder with upstream and downstream circular bar using lattice Boltzmann method

2018 ◽  
Vol 29 (04) ◽  
pp. 1850030 ◽  
Author(s):  
Yuan Ma ◽  
Rasul Mohebbi ◽  
M. M. Rashidi ◽  
Zhigang Yang
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Flow Patterns ◽  
Percentage Reduction ◽  
Square Cylinder ◽  
Distance Ratio ◽  
Maximum Percentage ◽  
Circular Bar ◽  
Boltzmann Method ◽  
Downstream Control

A numerical investigation is carried out to analyze the flow patterns, drag and lift coefficients, and vortex shedding around a square cylinder using a control circular bar upstream and downstream. Lattice Boltzmann method (LBM) was used to investigate flow over a square cylinder controlled by upstream and downstream circular bar, which is the main novelty of this study. Compared with those available results in the literature, the code for flow over a single square cylinder proves valid. The Reynolds number (Re) based on the width of the square cylinder ([Formula: see text]) and diameter of circular bar ([Formula: see text]) are 100 for square cylinder, 30 and 50 for different circular bars. Numerical simulations are performed in the ranges of [Formula: see text] and [Formula: see text], where [Formula: see text] and [Formula: see text] are the center-to-center distances between the bar and cylinder. Five distinct flow patterns are observed in the present study. It is found that the maximum percentage reduction in drag coefficient is 59.86% by upstream control bar, and the maximum percentage reduction in r.m.s. lift coefficient is 73.69% by downstream control bar. By varying the distance ratio for the downstream control bar, a critical value of distance ratio is found where there are two domain frequencies.

Analysis of genes under the downstream control of the t(8;21) fusion protein AML1-MTG8: overexpression of the TIS11b(ERF-1, cMG1) gene induces myeloid cell proliferation in response to G-CSF

Blood ◽  
2000 ◽  
Vol 96 (2) ◽  
pp. 655-663 ◽  
Author(s):  
Hiroyuki Shimada ◽  
Hitoshi Ichikawa ◽  
Sawako Nakamura ◽  
Rieko Katsu ◽  
Mitsuteru Iwasa ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Target Genes ◽  
Myeloid Cell ◽  
Myelogenous Leukemia ◽  
Leukemic Cells ◽  
Acute Myelogenous ◽  
Differentiation And Proliferation ◽  
Normal Differentiation ◽  
High Level ◽  
Downstream Control

The AML1-MTG8 fusion transcription factor generated by t(8;21) translocation is thought to dysregulate genes that are crucial for normal differentiation and proliferation of hematopoietic progenitors to cause acute myelogenous leukemia (AML). Although AML1-MTG8 has been shown to repress the transcription of AML1 targets, none of the known targets of AML1 are probably responsible for AML1-MTG8-mediated leukemogenesis. In this study, 24 genes under the downstream control of AML1-MTG8 were isolated by using a differential display technique. Analysis with deletion mutants of AML1-MTG8 demonstrated that the regulation of the majority of these genes requires the region of 51 residues (488-538) containing the Nervy homology region 2 (NHR2), through which AML1-MTG8 interacts with MTGR1. Among the 24 genes identified, 10 were considered to be genes under the control of AML1, because their expression was altered by AML1b or AML1a or both. However, the other 14 genes were not affected by either AML1b or AML1a, suggesting the possibility that AML1-MTG8 regulates a number of specific target genes that are not normally regulated by AML1. Furthermore, an up-regulated gene, TIS11b (ERF-1,cMG1), was highly expressed in t(8;21) leukemic cells, and the overexpression of TIS11b induced myeloid cell proliferation in response to granulocyte colony-stimulating factor. These results suggest that the high-level expression of TIS11b contributes to AML1-MTG8-mediated leukemogenesis.

scholarly journals Interaction of a Fin Trailing Vortex with a Downstream Control Surface

2008 ◽  
Author(s):  
Steven Beresh ◽  
Justin Smith ◽  
John Henfling ◽  
Thomas Grasser ◽  
Russell Spillers
Keyword(s):  
Control Surface ◽  
Downstream Control
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