scholarly journals Regions of very low H3K27me3 partition the Drosophila genome into topological domains

2016 ◽  
Author(s):  
Sherif El-Sharnouby ◽  
Bettina Fischer ◽  
Jose Paolo Magbanua ◽  
Benjamin Umans ◽  
Rosalyn Flower ◽  
...  
Keyword(s):  
Domain Architecture ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Drosophila Genome ◽  
Topological Domains ◽  
Transcription Start Sites ◽  
Genome Wide ◽  
Domain Boundaries ◽  
Topologically Associated Domains ◽  
Architectural Organization

AbstractBackgroundIt is now well established that eukaryote genomes have a common architectural organization into topologically associated domains (TADs) and evidence is accumulating that this organization plays an important role in gene regulation. However, the mechanisms that partition the genome into TADs and the nature of domain boundaries are still poorly understood.ResultsWe have investigated boundary regions in the Drosophila genome and find that they can be identified as domains of very low H3K27me3. The genome-wide H3K27me3 profile partitions into two states; very low H3K27me3 identifies Depleted (D) domains that contain housekeeping genes and their regulators such as the histone acetyltransferase-containing NSL complex, whereas domains containing mid-to-high levels of H3K27me3 (Enriched or E domains) are associated with regulated genes, irrespective of whether they are active or inactive. The D domains correlate with the boundaries of TADs and are enriched in a subset of architectural proteins, particularly Chromator, BEAF-32, and Z4/Putzig. However, rather than being clustered at the borders of these domains, these proteins bind throughout the H3K27me3-depleted regions and are much more strongly associated with the transcription start sites of housekeeping genes than with the H3K27me3 domain boundaries.ConclusionsWe suggest that the D domain chromatin state, characterised by very low H3K27me3 and established by housekeeping gene regulators, acts to separate topological domains thereby setting up the domain architecture of the genome.

scholarly journals Promoter-Proximal Chromatin Domain Insulator Protein BEAF Mediates Local and Long-Range Communication with a Transcription Factor and Directly Activates a Housekeeping Promoter in Drosophila

Genetics ◽  
2020 ◽  
Vol 215 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Yuankai Dong ◽  
S. V. Satya Prakash Avva ◽  
Mukesh Maharjan ◽  
Janice Jacobi ◽  
Craig M. Hart
Keyword(s):  
Gene Regulation ◽  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Binding Protein ◽  
Housekeeping Genes ◽  
Bimolecular Fluorescence Complementation ◽  
Chromatin Domain ◽  
Direct Role ◽  
Transcription Start Sites ◽  
Genome Wide

BEAF (Boundary Element-Associated Factor) was originally identified as a Drosophila melanogaster chromatin domain insulator-binding protein, suggesting a role in gene regulation through chromatin organization and dynamics. Genome-wide mapping found that BEAF usually binds near transcription start sites, often of housekeeping genes, suggesting a role in promoter function. This would be a nontraditional role for an insulator-binding protein. To gain insight into molecular mechanisms of BEAF function, we identified interacting proteins using yeast two-hybrid assays. Here, we focus on the transcription factor Serendipity δ (Sry-δ). Interactions were confirmed in pull-down experiments using bacterially expressed proteins, by bimolecular fluorescence complementation, and in a genetic assay in transgenic flies. Sry-δ interacted with promoter-proximal BEAF both when bound to DNA adjacent to BEAF or > 2-kb upstream to activate a reporter gene in transient transfection experiments. The interaction between BEAF and Sry-δ was detected using both a minimal developmental promoter (y) and a housekeeping promoter (RpS12), while BEAF alone strongly activated the housekeeping promoter. These two functions for BEAF implicate it in playing a direct role in gene regulation at hundreds of BEAF-associated promoters.

scholarly journals Genes Containing Long Introns Occupy Series of Bands and Interbands in Drosophila melanogaster Polytene Chromosomes

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 417
Author(s):  
Varvara A. Khoroshko ◽  
Galina V. Pokholkova ◽  
Victor G. Levitsky ◽  
Tatyana Yu. Zykova ◽  
Oksana V. Antonenko ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosomes ◽  
Housekeeping Genes ◽  
Wide Distribution ◽  
Gene Location ◽  
Gene Arrangement ◽  
Drosophila Genome ◽  
Genetic Organization ◽  
Genome Wide ◽  
Bioinformatic Approaches

The Drosophila melanogaster polytene chromosomes are the best model for studying the genome organization during interphase. Despite of the long-term studies available on genetic organization of polytene chromosome bands and interbands, little is known regarding long gene location on chromosomes. To analyze it, we used bioinformatic approaches and characterized genome-wide distribution of introns in gene bodies and in different chromatin states, and using fluorescent in situ hybridization we juxtaposed them with the chromosome structures. Short introns up to 2 kb in length are located in the bodies of housekeeping genes (grey bands or lazurite chromatin). In the group of 70 longest genes in the Drosophila genome, 95% of total gene length accrues to introns. The mapping of the 15 long genes showed that they could occupy extended sections of polytene chromosomes containing band and interband series, with promoters located in the interband fragments (aquamarine chromatin). Introns (malachite and ruby chromatin) in polytene chromosomes form independent bands, which can contain either both introns and exons or intron material only. Thus, a novel type of the gene arrangement in polytene chromosomes was discovered; peculiarities of such genetic organization are discussed.

scholarly journals Genome-wide identification and expression analysis of the Brassica oleracea L. chitin-binding genes and response to pathogens infections

Planta ◽  
2021 ◽  
Vol 253 (4) ◽  
Author(s):  
Mingzhao Zhu ◽  
Shujin Lu ◽  
Mu Zhuang ◽  
Yangyong Zhang ◽  
Honghao Lv ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Gene Family ◽  
Brassica Oleracea ◽  
Downy Mildew ◽  
Fusarium Wilt ◽  
Black Spot ◽  
Housekeeping Genes ◽  
Chitinase Gene ◽  
Genome Wide ◽  
A Genome

Abstract Main conclusion Chitinase family genes were involved in the response of Brassica oleracea to Fusarium wilt, powdery mildew, black spot and downy mildew. Abstract Abstract Chitinase, a category of pathogenesis-related proteins, is believed to play an important role in defending against external stress in plants. However, a comprehensive analysis of the chitin-binding gene family has not been reported to date in cabbage (Brassica oleracea L.), especially regarding the roles that chitinases play in response to various diseases. In this study, a total of 20 chitinase genes were identified using a genome-wide search method. Phylogenetic analysis was employed to classify these genes into two groups. The genes were distributed unevenly across six chromosomes in cabbage, and all of them contained few introns (≤ 2). The results of collinear analysis showed that the cabbage genome contained 1–5 copies of each chitinase gene (excluding Bol035470) identified in Arabidopsis. The heatmap of the chitinase gene family showed that these genes were expressed in various tissues and organs. Two genes (Bol023322 and Bol041024) were relatively highly expressed in all of the investigated tissues under normal conditions, exhibiting the expression characteristics of housekeeping genes. In addition, under four different stresses, namely, Fusarium wilt, powdery mildew, black spot and downy mildew, we detected 9, 5, 8 and 8 genes with different expression levels in different treatments, respectively. Our results may help to elucidate the roles played by chitinases in the responses of host plants to various diseases.

scholarly journals Assessment of common housekeeping genes as reference for gene expression studies using RT-qPCR in mouse choroid plexus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Hoa Ho ◽  
Annarita Patrizi
Keyword(s):  
Gene Expression ◽  
Choroid Plexus ◽  
Sensory Deprivation ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Experimental Conditions ◽  
Brain Repair ◽  
Expression Studies ◽  
Testing Algorithms ◽  
Gene Expression Studies

AbstractChoroid plexus (ChP), a vascularized secretory epithelium located in all brain ventricles, plays critical roles in development, homeostasis and brain repair. Reverse transcription quantitative real-time PCR (RT-qPCR) is a popular and useful technique for measuring gene expression changes and also widely used in ChP studies. However, the reliability of RT-qPCR data is strongly dependent on the choice of reference genes, which are supposed to be stable across all samples. In this study, we validated the expression of 12 well established housekeeping genes in ChP in 2 independent experimental paradigms by using popular stability testing algorithms: BestKeeper, DeltaCq, geNorm and NormFinder. Rer1 and Rpl13a were identified as the most stable genes throughout mouse ChP development, while Hprt1 and Rpl27 were the most stable genes across conditions in a mouse sensory deprivation experiment. In addition, Rpl13a, Rpl27 and Tbp were mutually among the top five most stable genes in both experiments. Normalisation of Ttr and Otx2 expression levels using different housekeeping gene combinations demonstrated the profound effect of reference gene choice on target gene expression. Our study emphasized the importance of validating and selecting stable housekeeping genes under specific experimental conditions.

scholarly journals Genome-Wide Expression Patterns of Rhoptry Kinases during the Eimeria tenella Life-Cycle

2021 ◽  
Vol 9 (8) ◽  
pp. 1621
Author(s):  
Adeline Ribeiro E Silva ◽  
Alix Sausset ◽  
Françoise I. Bussière ◽  
Fabrice Laurent ◽  
Sonia Lacroix-Lamandé ◽  
...  
Keyword(s):  
Life Cycle ◽  
Expression Patterns ◽  
Housekeeping Genes ◽  
Catalytic Triad ◽  
Eimeria Tenella ◽  
Apicomplexan Parasites ◽  
Genome Wide ◽  
Infected Cells ◽  
First And Second Generation

Kinome from apicomplexan parasites is composed of eukaryotic protein kinases and Apicomplexa specific kinases, such as rhoptry kinases (ROPK). Ropk is a gene family that is known to play important roles in host–pathogen interaction in Toxoplasma gondii but is still poorly described in Eimeria tenella, the parasite responsible for avian coccidiosis worldwide. In the E. tenella genome, 28 ropk genes are predicted and could be classified as active (n = 7), inactive (incomplete catalytic triad, n = 12), and non-canonical kinases (active kinase with a modified catalytic triad, n = 9). We characterized the ropk gene expression patterns by real-time quantitative RT-PCR, normalized by parasite housekeeping genes, during the E. tenella life-cycle. Analyzed stages were: non-sporulated oocysts, sporulated oocysts, extracellular and intracellular sporozoites, immature and mature schizonts I, first- and second-generation merozoites, and gametes. Transcription of all those predicted ropk was confirmed. The mean intensity of transcription was higher in extracellular stages and 7–9 ropk were specifically transcribed in merozoites in comparison with sporozoites. Transcriptional profiles of intracellular stages were closely related to each other, suggesting a probable common role of ROPKs in hijacking signaling pathways and immune responses in infected cells. These results provide a solid basis for future functional analysis of ROPK from E. tenella.

Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise

2004 ◽  
Vol 18 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Douglas J. Mahoney ◽  
Kate Carey ◽  
Ming-Hua Fu ◽  
Rodney Snow ◽  
David Cameron-Smith ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Real Time ◽  
Healthy Subjects ◽  
Acute Exercise ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Cycle Ergometry ◽  
Pcr Analysis ◽  
28S Rrna ◽  
Rt Pcr

Studies examining gene expression with RT-PCR typically normalize their mRNA data to a constitutively expressed housekeeping gene. The validity of a particular housekeeping gene must be determined for each experimental intervention. We examined the expression of various housekeeping genes following an acute bout of endurance (END) or resistance (RES) exercise. Twenty-four healthy subjects performed either a interval-type cycle ergometry workout to exhaustion (∼75 min; END) or 300 single-leg eccentric contractions (RES). Muscle biopsies were taken before exercise and 3 h and 48 h following exercise. Real-time RT-PCR was performed on β-actin, cyclophilin (CYC), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β2-microglobulin (β2M). In a second study, 10 healthy subjects performed 90 min of cycle ergometry at ∼65% of V̇o2 max, and we examined a fifth housekeeping gene, 28S rRNA, and reexamined β2M, from muscle biopsy samples taken immediately postexercise. We showed that CYC increased 48 h following both END and RES exercise (3- and 5-fold, respectively; P < 0.01), and 28S rRNA increased immediately following END exercise (2-fold; P = 0.02). β-Actin trended toward an increase following END exercise (1.85-fold collapsed across time; P = 0.13), and GAPDH trended toward a small yet robust increase at 3 h following RES exercise (1.4-fold; P = 0.067). In contrast, β2M was not altered at any time point postexercise. We conclude that β2M and β-actin are the most stably expressed housekeeping genes in skeletal muscle following RES exercise, whereas β2M and GAPDH are the most stably expressed following END exercise.

scholarly journals Genome-Wide Identification of Transcription Start Sites, Promoters and Transcription Factor Binding Sites in E. coli

PLoS ONE ◽  
2009 ◽  
Vol 4 (10) ◽  
pp. e7526 ◽  
Author(s):  
Alfredo Mendoza-Vargas ◽  
Leticia Olvera ◽  
Maricela Olvera ◽  
Ricardo Grande ◽  
Leticia Vega-Alvarado ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Binding Sites ◽  
Transcription Factor Binding Sites ◽  
Transcription Factor Binding ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
E Coli ◽  
Factor Binding ◽  
Genome Wide

Methodologies for specific intron and exon RNA localization in cultured cells by haptenized and fluorochromized probes

1993 ◽  
Vol 104 (4) ◽  
pp. 1187-1197 ◽  
Author(s):  
R.W. Dirks ◽  
F.M. van de Rijke ◽  
S. Fujishita ◽  
M. van der Ploeg ◽  
A.K. Raap
Keyword(s):  
In Situ Hybridization ◽  
Cell Lines ◽  
Cultured Cells ◽  
Direct Detection ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Immediate Early ◽  
High Signal ◽  
Pretreatment Conditions

We have determined optimal conditions for the detection of mRNA sequences in cultured cells by nonradioactive in situ hybridization. For this purpose a number of different cell lines have been used: rat 9G cells for the detection of human cytomegalovirus immediate early mRNA, and HeLa as well as 5637 carcinoma cells for the detection of housekeeping gene mRNAs. Extensive optimization of fixation and pretreatment conditions revealed that most intense hybridization signals are obtained when cells are grown on glass microscope slides, fixed with a mixture of formaldehyde and acetic acid, pretreated with pepsin and denatured prior to hybridization. In addition, we also studied the potential of fluorochromized probes for the direct detection of multiple RNA sequences. The optimized in situ hybridization procedure revealed that immediate early mRNA transcripts are, in addition to a cytoplasmic localization, localized within nuclei of rat 9G cells. Double hybridization experiments showed that intron and exon sequences colocalize within the main nuclear signal. In addition, the presence of small, intron-specific, fluorescent spots scattered around the main nuclear signals indicates that intron sequences which are spliced out can be visualized. Additional information about the functioning of cells could be obtained by the detection of mRNA simultaneously with bromodeoxyuridine, incorporated during S-phase, or its cognate protein. The sensitivity of these methods is such that mRNAs of abundantly expressed housekeeping genes can be detected in a variety of cell lines with high signal to noise ratios.

scholarly journals Organization and expression of the cell cycle gene, ts11, that encodes asparagine synthetase.

1989 ◽  
Vol 9 (6) ◽  
pp. 2350-2359 ◽  
Author(s):  
A Greco ◽  
S S Gong ◽  
M Ittmann ◽  
C Basilico
Keyword(s):  
Cell Cycle ◽  
Housekeeping Genes ◽  
Chloramphenicol Acetyltransferase ◽  
Product Inhibition ◽  
Asparagine Synthetase ◽  
Cell Cycle Gene ◽  
Mrna Levels ◽  
Nonpermissive Temperature ◽  
Regulation Of Expression ◽  
Transcription Start Sites

The human ts11 gene was isolated on the basis of its ability to complement the mutation of the BHK cell cycle ts11 mutant, which is blocked in G1 at the nonpermissive temperature. This gene has now been identified as the structural gene for asparagine synthetase (AS) on the bases of sequence homology and the ability of exogenous asparagine to bypass the ts11 block. The ts11 (AS) mRNA has a size of about 2 kilobases and is induced in mid-G1 phase in human, mouse, and hamster cell lines. We have studied the organization and regulation of expression of the ts11 gene. The human ts11 gene consists of 13 exons (the first two noncoding) interspersed in a region of about 21 kilobases of DNA. Transient expression assays using the bacterial chloramphenicol acetyltransferase reporter gene identified two separate promoters: one (ts11 P1) contained in a 280-base-pair region upstream of the first exon and the other (ts11 P2) contained in the first intron. ts11 P1 produced about sixfold more chloramphenicol acetyltransferase activity than did ts11 P2 and had features of the promoters of housekeeping genes: high G + C content, multiple transcription start sites, absence of a TATA box, and presence of putative Sp1 binding sites. ts11 P2 contained a TATA sequence and other elements characteristic of a promoter, but so far we have no evidence of its physiological utilization. The ts11 gene was overexpressed in ts11 cells exposed to the nonpermissive temperature. Addition of asparagine to the culture medium led to a drastic decrease in mRNA levels and prevented G1 induction in serum-stimulated cells, which indicated that expression of the AS gene is regulated by a mechanism of end product inhibition.

scholarly journals Molecular data analysis of selected housekeeping and informational genes from nineteen Campylobacter jejuni genomes

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 87 ◽  
Author(s):  
Vathsala Mohan ◽  
Mark Stevenson
Keyword(s):  
Information Processing ◽  
Campylobacter Jejuni ◽  
Genetic Recombination ◽  
Bacterial Species ◽  
Housekeeping Genes ◽  
Housekeeping Gene ◽  
Molecular Data ◽  
Sequence Type ◽  
Molecular Characteristics ◽  
Research Article

Campylobacter jejuni (C. jejuni) is a rapidly evolving bacterial species with massive genetic recombination potential to generate niche specific genotypes. Generally the housekeeping gene lineage has been evidenced to undergo lateral gene transfer and recombination fairly frequently compared to the information processing gene lineage. During such exchanges, gene amelioration takes place over time acquiring the host genomes’ molecular characteristics. In this study fifty genes that comprised twenty five housekeeping lineage genes and twenty five information processing lineage genes from nineteen C. jejuni genomes were studied. These nineteen genomes included seven C. jejuni isolates that belonged to the same genotype or multilocus sequence type ST-474. The genes from both lineages were tested for recombination and the guanine-cytosine (GC) variation. This paper details about the data collected and the analyses performed in the corresponding research article entitled ”Campylobacter jejuni genomes exhibit notable GC variation within housekeeping genes”. Further, this paper provides details on the results that are not included in the research paper to provide completeness to the study conducted. The gene sequences from the seven C. jejuni ST-474 isolates were submitted to the GenBank and the corresponding gene IDs are provided for referencing purposes.

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