Identification of target genes regulated by homeotic proteins in Drosophila melanogaster through genetic selection of Ultrabithorax protein-binding sites in yeast.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 349-363 ◽  
Author(s):  
G S Mastick ◽  
R McKay ◽  
T Oligino ◽  
K Donovan ◽  
A J López
Keyword(s):  
Drosophila Melanogaster ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Expression Patterns ◽  
Genetic Selection ◽  
Single Copy ◽  
Transcription Unit ◽  
Yeast Cells ◽  
Drosophila Genome ◽  
Candidate Target

Abstract A method based on the transcriptional activation of a selectable reporter in yeast cells was used to identify genes regulated by the Ultrabithorax homeoproteins in Drosophila melanogaster. Fifty-three DNA fragments that can mediate activation by UBX isoform Ia in this test were recovered after screening 15% of the Drosophila genome. Half of these fragments represent single-copy sequences in the genome. Six single-copy fragments were investigated in detail, and each was found to reside near a transcription unit whose expression in the embryo is segmentally modulated as expected for targets of homoeotic genes. Four of these putative target genes are expressed in patterns that suggest roles in the development of regional specializations within mesoderm derivatives; in three cases these expression patterns depend on Ultrabithorax function. Extrapolation from this pilot study indicates that 85-170 candidate target genes can be identified by screening the entire Drosophila genome with UBX isoform Ia. With appropriate modifications, this approach should be applicable to other transcriptional regulators in diverse organisms.

scholarly journals Key Regulatory Pathways, MicroRNAs, and Target Genes Participate in Adventitious Root Formation of Acer Rubrum L

2021 ◽  
Author(s):  
Wenpeng Zhu ◽  
Manyu Zhang ◽  
Jianyi Li ◽  
Hewen Zhao ◽  
Kezhong Zhang ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
High Throughput Sequencing ◽  
Target Genes ◽  
Seedling Survival ◽  
Expression Patterns ◽  
Economic Value ◽  
Acer Rubrum ◽  
Pcr Analysis ◽  
Asexual Propagation ◽  
Regulatory Pathways

Abstract BackgroundAcer rubrum L. is a colorful ornamental tree with great economic value. Because this tree is difficult to root under natural conditions and the seedling survival rate is low, vegetative propagation methods are often used. Because the formation of adventitious roots (ARs) is essential for the survival of asexual propagation of A. rubrum, it is necessary to investigate the molecular regulatory mechanisms in the formation of ARs of A. ruburm. To address this knowledge gap, we sequenced the transcriptome and sRNA of the A. rubrum variety ‘Autumn Fantasy’ using high-throughput sequencing and explored changes in gene and microRNA (miRNA) expression in response to exogenous auxin treatment. ResultsWe identified 82,468 differentially expressed genes between the treated and untreated ARs, as well as 48 known and 95 novel miRNAs. We also identified 172 target genes of the known miRNAs using degradome sequencing. Two regulatory pathways (ubiquitin mediated proteolysis and plant hormone signal transduction), Ar-miR160a and the target gene ArARF10 were shown to be involved in the auxin response. We further investigated the expression patterns and regulatory roles of ArARF10 through subcellular localization, transcriptional activation, plant transformation, qRT-PCR analysis, and GUS staining. ConclusionsDifferential expression patterns indicated the Ar-miR160a-ArARF10 interaction might play a significant role in the regulation of AR formation in A. rubrum. Our study provided new insights into mechanisms underlying the regulation of AR formation in A. rubrum.

Rates and patterns of scnDNA and mtDNA divergence within the Drosophila melanogaster subgroup.

Genetics ◽  
1988 ◽  
Vol 118 (4) ◽  
pp. 671-683
Author(s):  
A Caccone ◽  
G D Amato ◽  
J R Powell
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Hybridization ◽  
Nuclear Dna ◽  
Single Copy ◽  
Rate Of Change ◽  
Drosophila Genome ◽  
Island Species ◽  
Drosophila Melanogaster Subgroup ◽  
Chromosomal Data ◽  
Group 2

Abstract Levels of DNA divergence among the eight species of the Drosophila melanogaster subgroup and D. takahashii have been determined using the technique of DNA-DNA hybridization. Two types of DNA were used: single-copy nuclear DNA (scnDNA) and mitochondrial DNA (mtDNA). The major findings are: (1) A phylogeny has been derived for the group based on scnDNA which is congruent with chromosomal data, morphology, and behavior. The three homosequential species, simulans, sechellia, and mauritiana, are very closely related; the scnDNA divergence indicate the two island species are a monophyletic group. (2) The rates of change of scnDNA and mtDNA are not greatly different; if anything scnDNA evolves faster than mtDNA. (3) The rates of scnDNA evolution are not closely correlated to chromosomal (inversion) evolution. (4) The Drosophila genome appears to consist of two distinct classes of scnDNA with respect to rate of evolutionary change, a very rapidly evolving fraction and a relatively conservative fraction. (5) The absolute rate of change was estimated to be at least 1.7% nucleotide substitution per one million years. (6) DNA distance estimates based on restriction site variation are correlated with distances based on DNA-DNA hybridization, although the correlation is not very strong.

Identification of Distinct inv(16) Subclasses in Adult Acute Myeloid Leukemia Based on Gene Expression Profiling.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2037-2037
Author(s):  
Lars Bullinger ◽  
Claudia Scholl ◽  
Eric Bair ◽  
Konstanze Dohner ◽  
Stefan Frohling ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Target Genes ◽  
Expression Patterns ◽  
Rank Test ◽  
Survival Times ◽  
Strong Trend ◽  
Candidate Target ◽  
Acute Myeloid

Abstract Recurrent cytogenetic aberrations have been shown to constitute markers of diagnostic and prognostic value in acute myeloid leukemia (AML). However, even within the well-defined cytogenetic AML subgroup with an inv(16) we see substantial biological and clinical heterogeneity which is not fully reflected by the current classification system. To better characterize this cytogenetic group on the molecular level we profiled gene expression in a series of adult AML patients (n=26) with inv(16) using 42k cDNA microarrays. By unsupervised hierarchical clustering we observed that samples with inv(16) separated primarily into two different subgroups. These showed no significant differences regarding known risk factors like age, WBC, LDH, etc. However, these newly defined inv(16)-subgroups were characterized by distinct clinical behavior. There was a strong trend towards unfavorable outcome with shorter overall survival times in one group (P=0.09, log rank test). Since the primary translocation/inversion events themselves are not sufficient for leukemogenesis, distinct patterns of gene expression found within each of these cytogenetic groups may suggest alternative cooperating mutations and deregulated pathways leading to transformation. Therefore, we performed a supervised analysis to determine the characteristic gene expression patterns underlying the cluster-defined subgroups. This Significance Analysis of Microarrays (SAM) method identified 260 genes significantly differentially expressed between the two newly defined inv(16)-subgroups (false discovery rate = 0.002). High expression levels of JUN, JUNB, JUND, FOS and FOSB characterized the first inv(16) subgroup (having less favorable prognosis). FOS gene family members can dimerize with proteins of the JUN family, forming the transcription factor complex AP-1 which has been implicated in the regulation of cell proliferation, differentiation, and transformation. Among the second subgroup, the proto-oncogene ETS1,displayed elevated expression, possibly resulting from aberrant MEK/ERK pathway activation as these cases also showed an over-expression of MAP3K1 and MAP3K2. In conclusion, both supervised and unsupervised methods provide numerous insights into the pathogenesis of AML with inv(16), identifying clinically significant patterns of gene expression, as well as candidate target genes involved in leukemogenesis.

scholarly journals A Bayesian framework for inter-cellular information sharing improves dscRNA-seq quantification

2020 ◽  
Author(s):  
Avi Srivastava ◽  
Laraib Malik ◽  
Hirak Sarkar ◽  
Rob Patro
Keyword(s):  
Information Sharing ◽  
Target Genes ◽  
Expression Patterns ◽  
Sampling Bias ◽  
Bayesian Framework ◽  
Accurate Estimation ◽  
Multiple Modalities ◽  
Gene Level ◽  
Candidate Target ◽  
Empirical Priors

AbstractMotivationDroplet based single cell RNA-seq (dscRNA-seq) data is being generated at an unprecedented pace, and the accurate estimation of gene level abundances for each cell is a crucial first step in most dscRNA-seq analyses. When preprocessing the raw dscRNA-seq data to generate a count matrix, care must be taken to account for the potentially large number of multi-mapping locations per read. The sparsity of dscRNA-seq data, and the strong 3’ sampling bias, makes it difficult to disambiguate cases where there is no uniquely mapping read to any of the candidate target genes.ResultsWe introduce a Bayesian framework for information sharing across cells within a sample, or across multiple modalities of data using the same sample, to improve gene quantification estimates for dscRNA-seq data. We use an anchor-based approach to connect cells with similar gene expression patterns, and learn informative, empirical priors which we provide to alevin’s gene multi-mapping resolution algorithm. This improves the quantification estimates for genes with no uniquely mapping reads (i.e. when there is no unique intra-cellular information). We show our new model improves the per cell gene level estimates and provides a principled framework for information sharing across multiple modalities. We test our method on a combination of simulated and real datasets under various setups.AvailabilityThe information sharing model is included in alevin and is implemented in C++14. It is available as open-source software, under GPL v3, at https://github.com/COMBINE-lab/salmon as of version [email protected], [email protected]

scholarly journals Key Regulatory Pathways, microRNAs, and Target Genes Participate in Adventitious Root Formation of Acer Rubrum L.

2021 ◽  
Author(s):  
Wenpeng Zhu ◽  
Manyu Zhang ◽  
Jianyi Li ◽  
Hewen Zhao ◽  
Kezhong Zhang ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
High Throughput Sequencing ◽  
Target Genes ◽  
Seedling Survival ◽  
Expression Patterns ◽  
Economic Value ◽  
Acer Rubrum ◽  
Pcr Analysis ◽  
Asexual Propagation ◽  
Regulatory Pathways

Abstract BackgroundAcer rubrum L. is a colorful ornamental tree with great economic value. Because this tree is difficult to root under natural conditions and the seedling survival rate is low, vegetative propagation methods are often used. Because the formation of adventitious roots (ARs) is essential for the survival of asexual propagation of A. rubrum, it is necessary to investigate the molecular regulatory mechanisms in the formation of ARs of A. ruburm. To address this knowledge gap, we sequenced the transcriptome and sRNA of the A. rubrum variety ‘Autumn Fantasy’ using high-throughput sequencing and explored changes in gene and microRNA (miRNA) expression in response to exogenous auxin treatment. ResultsWe identified 82,468 differentially expressed genes between the treated and untreated ARs, as well as 48 known and 95 novel miRNAs. We also identified 172 target genes of the known miRNAs using degradome sequencing. Two regulatory pathways (ubiquitin mediated proteolysis and plant hormone signal transduction), Ar-miR160a and the target gene ArARF10 were shown to be involved in the auxin response. We further investigated the expression patterns and regulatory roles of ArARF10 through subcellular localization, transcriptional activation, plant transformation, qRT-PCR analysis, and GUS staining. ConclusionsDifferential expression patterns indicated the Ar-miR160a-ArARF10 interaction might play a significant role in the regulation of AR formation in A. rubrum. Our study provided new insights into mechanisms underlying the regulation of AR formation in A. rubrum.

scholarly journals The organization and expression of the light gene, a heterochromatic gene of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 125 (1) ◽  
pp. 129-140 ◽  
Author(s):  
R H Devlin ◽  
B Bingham ◽  
B T Wakimoto
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Sequences ◽  
Molecular Mapping ◽  
Single Copy ◽  
Transcription Unit ◽  
Malpighian Tubules ◽  
Centromeric Heterochromatin ◽  
Chromosome 2 ◽  
Induced Mutations ◽  
Flanking Regions

Abstract The light (lt) gene is located in the centromeric heterochromatin of chromosome 2 of Drosophila melanogaster. This gene is necessary for normal levels of pigmentation in a number of adult and larval tissues and is required for viability. Hybrid dysgenic and X-ray induced mutations have been used to identify the gene and compare its organization to that of euchromatic genes. Molecular mapping of lt mutations and its major transcripts has shown that the lt gene is at least 17 kb. By injecting cosmid clones that include this region into lt mutant embryos, we have defined a 30-kb region that can transiently rescue the pigmentation defect in the Malpighian tubules. The major transcription unit of this gene is comprised of exons that are single copy. It is unusual in its organization in having a heterogeneous array of middle repetitive DNA sequences within its intronic and flanking regions.

scholarly journals Induction of the HIF pathway: Differential regulation by chemical hypoxia and oxygen glucose deprivation

2019 ◽  
Author(s):  
Alicia E. Novak ◽  
Susan M. Jones ◽  
J. Paul Elliott
Keyword(s):  
Transcriptional Activation ◽  
Cellular Response ◽  
Target Genes ◽  
Expression Patterns ◽  
Hypoxia Inducible Factor ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Oxygen Levels ◽  
Chemical Hypoxia ◽  
Hif Pathway

AbstractThe Hypoxia Inducible Factor (HIF) proteins are the master regulators in the cellular response to varying oxygen levels, including hypoxia. The HIF complex is stabilized and accumulates when oxygen levels drop through inhibition of a degradative enzyme. An active HIF complex can act as a transcriptional regulator of hundreds of genes. In turn, these genes determine the response of the cell by inducing pathways which can promote survival, or result in cell death. However, little is known about the regulation of the transcriptional process. We were interested in learning more about the time dependence of transcriptional activation in order to target those pathways which could enhance cell survival after ischemia. Using mouse hippocampal organotypic cultures (HOTCs), we compared oxygen-glucose deprivation with the hypoxia mimetic cobalt, which inhibits the oxygen dependent prolyl hydroylase and blocks degradation of the HIF proteins. We demonstrated that two of the most studied HIF target genes (VEGF, EPO) as well as HIF structural genes show complex time and dose-dependent expression patterns in response to the two different insults. Understanding of these molecular responses is crucial for the development of future treatments to enhance recovery from hypoxia and stroke.

scholarly journals A Bayesian framework for inter-cellular information sharing improves dscRNA-seq quantification

2020 ◽  
Vol 36 (Supplement_1) ◽  
pp. i292-i299
Author(s):  
Avi Srivastava ◽  
Laraib Malik ◽  
Hirak Sarkar ◽  
Rob Patro
Keyword(s):  
Information Sharing ◽  
Target Genes ◽  
Expression Patterns ◽  
Sampling Bias ◽  
Bayesian Framework ◽  
Accurate Estimation ◽  
Multiple Modalities ◽  
Gene Level ◽  
Candidate Target ◽  
Empirical Priors

Abstract Motivation Droplet-based single-cell RNA-seq (dscRNA-seq) data are being generated at an unprecedented pace, and the accurate estimation of gene-level abundances for each cell is a crucial first step in most dscRNA-seq analyses. When pre-processing the raw dscRNA-seq data to generate a count matrix, care must be taken to account for the potentially large number of multi-mapping locations per read. The sparsity of dscRNA-seq data, and the strong 3’ sampling bias, makes it difficult to disambiguate cases where there is no uniquely mapping read to any of the candidate target genes. Results We introduce a Bayesian framework for information sharing across cells within a sample, or across multiple modalities of data using the same sample, to improve gene quantification estimates for dscRNA-seq data. We use an anchor-based approach to connect cells with similar gene-expression patterns, and learn informative, empirical priors which we provide to alevin’s gene multi-mapping resolution algorithm. This improves the quantification estimates for genes with no uniquely mapping reads (i.e. when there is no unique intra-cellular information). We show our new model improves the per cell gene-level estimates and provides a principled framework for information sharing across multiple modalities. We test our method on a combination of simulated and real datasets under various setups. Availability and implementation The information sharing model is included in alevin and is implemented in C++14. It is available as open-source software, under GPL v3, at https://github.com/COMBINE-lab/salmon as of version 1.1.0.

Expression patterns of vHNF1 and HNF1 homeoproteins in early postimplantation embryos suggest distinct and sequential developmental roles

Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 783-797 ◽  
Author(s):  
S. Cereghini ◽  
M.O. Ott ◽  
S. Power ◽  
M. Maury
Keyword(s):  
Transcriptional Activation ◽  
Target Genes ◽  
Fetal Liver ◽  
Expression Patterns ◽  
Yolk Sac ◽  
Control Element ◽  
Visceral Endoderm ◽  
Mouse Development ◽  
F9 Cells

The homeoproteins HNF1 (LFB1/HNF1-A) and vHNF1 (LFB3/HNF1 beta) interact with an essential control element of a group of liver-specific genes. During development, these putative target genes are initially expressed in the visceral endoderm of the yolk sac and subsequently in fetal liver. To assess the possible involvement of HNF1 and/or vHNF1 as transcriptional regulators in the early steps of visceral endoderm differentiation, we have analyzed the expression pattern of both factors both in vitro during differentiation of murine F9 embryonal carcinoma cells and in vivo during early postimplantation mouse development. We show here that differentiation of F9 cells into either visceral or parietal endoderm is accompanied by a sharp induction in vHNF1 mRNA and protein. By contrast, only low levels of aberrantly sized HNF1 transcripts, but not DNA-binding protein, are found in F9 cells and its differentiated derivatives. At 6–7.5 days of gestation, high levels of vHNF1 mRNA are present in the visceral extraembryonic endoderm, which co-localize with transcripts of the transthyretin gene. HNF1 transcripts are first detected in the yolk sac roughly two embryonic days later, after the developmental onset of transcription of target genes. As development proceeds, discrepancies are observed between the level of transcripts of both vHNF1 and HNF1 and their respective nuclear binding proteins, notably in the yolk sac and embryonic kidney. In addition, we show that two alternative spliced isoforms of vHNF1 mRNA, vHNF-A and vHNF1-B, are expressed in both embryonic and adult tissues. Taken together, these data suggest that vHNF1 participates as a regulatory factor in the initial transcriptional activation of the target genes in the visceral endoderm of the yolk sac, whereas the later appearance of HNF1 could be required for maintenance of their expression. Our results also provide evidence of a posttranscriptional level of control of vHNF1 and HNF1 gene expression during development, in addition to the spatial restriction in transcription.

scholarly journals Growth Phase- and Cell Division-Dependent Activation and Inactivation of the σ32 Regulon in Escherichia coli

2008 ◽  
Vol 191 (5) ◽  
pp. 1695-1702 ◽  
Author(s):  
Maria Anna Wagner ◽  
Doris Zahrl ◽  
Gernot Rieser ◽  
Günther Koraimann
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Stationary Phase ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Expression Patterns ◽  
Logarithmic Phase ◽  
Protein Levels ◽  
Late Logarithmic Phase ◽  
Functional Inactivation

ABSTRACT Alternative sigma factors allow bacteria to reprogram global transcription rapidly and to adapt to changes in the environment. Here we report on growth- and cell division-dependent σ32 regulon activity in Escherichia coli in batch culture. By analyzing σ32 expression in growing cells, an increase in σ32 protein levels is observed during the first round of cell division after exit from stationary phase. Increased σ32 protein levels result from transcriptional activation of the rpoH gene. After the first round of bulk cell division, rpoH transcript levels and σ32 protein levels decrease again. The late-logarithmic phase and the transition to stationary phase are accompanied by a second increase in σ32 levels and enhanced stability of σ32 protein but not by enhanced transcription of rpoH. Throughout growth, σ32 target genes show expression patterns consistent with oscillating σ32 protein levels. However, during the transition to early-stationary phase, despite high σ32 protein levels, the transcription of σ32 target genes is downregulated, suggesting functional inactivation of σ32. It is deduced from these data that there may be a link between σ32 regulon activity and cell division events. Further support for this hypothesis is provided by the observation that in cells in which FtsZ is depleted, σ32 regulon activation is suppressed.

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