scholarly journals Control of yeast gene expression by transposable elements: maximum expression requires a functional Ty activator sequence and a defective Ty promoter.

1988 ◽  
Vol 8 (10) ◽  
pp. 4009-4017 ◽  
Author(s):  
L R Coney ◽  
G S Roeder

Integration of a transposable element adjacent to a gene frequently results in an alteration in expression of the nearby gene. The purpose of our experiments was to identify cis-acting sequences within a yeast transposon (Ty) that are important for expression of the adjacent gene. The role of these sequences in Ty transcription was also analyzed in order to examine the relationship between Ty and adjacent gene expression. Three naturally occurring Ty elements located at the HIS4 locus were examined. These Ty elements differed by multiple sequence changes and had different effects on HIS4 expression. To determine which sequences were important to Ty and HIS4 expression, Ty::lacZ and Ty::HIS4::lacZ fusion genes were constructed and analyzed. Results of these experiments indicated that a sequence element is present in the Ty epsilon region that is necessary for HIS4 expression but which has only a modest effect on Ty transcription. Additionally, a mutation in the Ty promoter region decreased Ty transcription and increased HIS4 expression. The opposite effects of this mutation on Ty and adjacent gene expression were probably caused by promoter competition.

1988 ◽  
Vol 8 (10) ◽  
pp. 4009-4017
Author(s):  
L R Coney ◽  
G S Roeder

Integration of a transposable element adjacent to a gene frequently results in an alteration in expression of the nearby gene. The purpose of our experiments was to identify cis-acting sequences within a yeast transposon (Ty) that are important for expression of the adjacent gene. The role of these sequences in Ty transcription was also analyzed in order to examine the relationship between Ty and adjacent gene expression. Three naturally occurring Ty elements located at the HIS4 locus were examined. These Ty elements differed by multiple sequence changes and had different effects on HIS4 expression. To determine which sequences were important to Ty and HIS4 expression, Ty::lacZ and Ty::HIS4::lacZ fusion genes were constructed and analyzed. Results of these experiments indicated that a sequence element is present in the Ty epsilon region that is necessary for HIS4 expression but which has only a modest effect on Ty transcription. Additionally, a mutation in the Ty promoter region decreased Ty transcription and increased HIS4 expression. The opposite effects of this mutation on Ty and adjacent gene expression were probably caused by promoter competition.


2021 ◽  
Author(s):  
Tianyu Dong ◽  
Xiaoyan Wei ◽  
Qianting Qi ◽  
Peilei Chen ◽  
Yanqing Zhou ◽  
...  

Abstract Background: Epigenetic regulation plays a significant role in the accumulation of plant secondary metabolites. The terpenoids are the most abundant in the secondary metabolites of plants, iridoid glycosides belong to monoterpenoids which is one of the main medicinal components of R.glutinosa. At present, study on iridoid glycosides mainly focuses on its pharmacology, accumulation and distribution, while the mechanism of its biosynthesis and the relationship between DNA methylation and plant terpene biosynthesis are seldom reports. Results: The research showed that the expression of DXS, DXR, 10HGO, G10H, GPPS and accumulation of iridoid glycosides increased at first and then decreased with the maturity of R.glutinosa, and under different concentrations of 5-azaC, the expression of DXS, DXR, 10HGO, G10H, GPPS and the accumulation of total iridoid glycosides were promoted, the promotion effect of low concentration (15μM-50μM) was more significant, the content of genomic DNA 5mC decreased significantly, the DNA methylation status of R.glutinosa genomes was also changed. DNA demethylation promoted gene expression and increased the accumulation of iridoid glycosides, but excessive demethylation inhibited gene expression and decreased the accumulation of iridoid glycosides. Conclusion: The analysis of DNA methylation, gene expression, and accumulation of iridoid glycoside provides insights into accumulation of terpenoids in R.glutinosa and lays a foundation for future studies on the effects of epigenetics on the synthesis of secondary metabolites.


1988 ◽  
Vol 8 (6) ◽  
pp. 2572-2580
Author(s):  
A Goel ◽  
R E Pearlman

In our studies on the regulation of adjacent-gene expression by Ty sequences, we demonstrated that a single-base-pair change (T-A----C-G) in the epsilon sequence of Ty917-derived elements is primarily responsible for enhancement of beta-galactosidase expression from lacZ fusion plasmids. Using an electrophoretic gel mobility assay, we showed that the same base pair transition is required for binding of a trans-acting factor, TyBF, from crude cell extracts in vitro. We identified the site of TyBF binding and determined the guanine nucleotide contact sites required for TyBF interaction. We propose that TyBF binding to cis-acting Ty2 sequences activates adjacent-gene transcription.


Author(s):  
Priyadarshni Patel ◽  
Jeganathan Ramesh Babu ◽  
Xu Wang ◽  
Thangiah Geetha

Obesity is caused by a combination of hereditary and environmental factors. Despite extensive study, contemporary through diet, exercise, education, surgery, and pharmacological treatments, no effective long-term solution has been found to this epidemic. Over the last decade, there has been a tremendous advancement in understanding the science of epigenetics, as well as a rise in public interest in learning more about the influence of diet and lifestyle choices on the health of an individual. Without affecting the underlying DNA sequence, epigenetic alterations impact gene expression. Previous animal studies have shown a link between the type of diet and expression or suppression of obesity genes, but there are very few human studies that demonstrate the relationship between dietary intake and obesity gene expression. This review highlights the effects of carbohydrates, lipids, and protein intake from the diet on obesity-related genes.


1987 ◽  
Vol 7 (4) ◽  
pp. 1563-1567 ◽  
Author(s):  
D O Peterson ◽  
K K Beifuss ◽  
K L Morley

A sequence element within pBR322 DNA mediates a cis-acting negative effect on expression from eucaryotic genes in transient expression assays. The negative element overlaps with sequences that inhibit DNA replication, but its effect is observed in the absence of detectable replication of transfected DNA.


2015 ◽  
Vol 173 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Masanori Murakami ◽  
Takanobu Yoshimoto ◽  
Kazuhiko Nakabayashi ◽  
Kyoichiro Tsuchiya ◽  
Isao Minami ◽  
...  

ObjectiveThe pathophysiology of aldosterone-producing adenomas (APA) has been investigated intensively through genetic and genomic approaches. However, the role of epigenetics in APA is not fully understood. In the present study, we explored the relationship between gene expression and DNA methylation status in APA.MethodsWe conducted an integrated analysis of transcriptome and methylome data of paired APA-adjacent adrenal gland (AAG) samples from the same patient. The adrenal specimens were obtained from seven Japanese patients with APA who underwent adrenalectomy. Gene expression and genome-wide CpG methylation profiles were obtained from RNA and DNA samples that were extracted from those seven paired tissues.ResultsMethylome analysis showed global CpG hypomethylation in APA relative to AAG. The integration of gene expression and methylation status showed that 34 genes were up-regulated with CpG hypomethylation in APA. Of these, three genes (CYP11B2, MC2R, and HPX) may be related to aldosterone production, and five genes (PRRX1, RAB38, FAP, GCNT2, and ASB4) are potentially involved in tumorigenesis.ConclusionThe present study is the first methylome analysis to compare APA with AAG in the same patients. Our integrated analysis of transcriptome and methylome revealed DNA hypomethylation in APA and identified several up-regulated genes with DNA hypomethylation that may be involved in aldosterone production and tumorigenesis.


2021 ◽  
Author(s):  
Caroline Meguerditchian ◽  
Ayse Ergun ◽  
Veronique DECROOCQ ◽  
Marie LEFEBVRE ◽  
Quynh Trang Bui

Understanding the relationship between transposable elements (TEs) and their associated genes in the host genome is a key point to explore their potential role in genome evolution. Transposable elements can regulate and affect gene expression not only because of their mobility within the genome but also because of its transcriptional activity. Gene expression can be suppressed, decreased or increased and cellular signalling pathways can be activated through the act of the nearby TE expression itself or subsequent TE replication intermediates. We implemented a pipeline which is capable to reveal the relationship between TEs and adjacent gene distribution in the host genome. Our tool is freely available here : https://github.com/marieBvr/TEs_genes_relationship_pipeline


2016 ◽  
Author(s):  
Lain Guio ◽  
Cristina Vieira ◽  
Josefa González

ABSTRACTTransposable elements are emerging as an important source of cis-acting regulatory sequences and epigenetic marks that could influence gene expression. However, few studies have dissected the role of specific transposable element insertions on epigenetic gene regulation. Bari-Jheh is a natural transposon that mediates resistance to oxidative stress by adding cis-regulatory sequences that affect expression of nearby genes. In this work, we integrated publicly available data with chromatin immunoprecipitation experiments to get a more comprehensive picture of Bari-Jheh molecular effects. We showed that Bari-Jheh was enriched for H3K9me3 in nonstress conditions, and for H3K9me3, H3K4me3 and H3K27me3 in oxidative stress conditions, which is consistent with expression changes in adjacent genes. We further showed that under oxidative stress conditions, H3K4me3 and H3K9me3 spread to the promoter region of Jheh1 gene. Finally, another insertion of the Bari1 family was associated with increased H3K27me3 in oxidative stress conditions suggesting that Bari1 histone marks are copy-specific. We concluded that besides adding cis-regulatory sequences, Bari-Jheh influences gene expression by affecting the local chromatin state.


Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1707 ◽  
Author(s):  
Laura Di Renzo ◽  
Paola Gualtieri ◽  
Lorenzo Romano ◽  
Giulia Marrone ◽  
Annalisa Noce ◽  
...  

Human nutrition is a branch of medicine based on foods biochemical interactions with the human body. The phenotypic transition from health to disease status can be attributed to changes in genes and/or protein expression. For this reason, a new discipline has been developed called “-omic science”. In this review, we analyzed the role of “-omics sciences” (nutrigenetics, nutrigenomics, proteomics and metabolomics) in the health status and as possible therapeutic tool in chronic degenerative diseases. In particular, we focused on the role of nutrigenetics and the relationship between eating habits, changes in the DNA sequence and the onset of nutrition-related diseases. Moreover, we examined nutrigenomics and the effect of nutrients on gene expression. We perused the role of proteomics and metabolomics in personalized nutrition. In this scenario, we analyzed also how dysbiosis of gut microbiota can influence the onset and progression of chronic degenerative diseases. Moreover, nutrients influencing and regulating gene activity, both directly and indirectly, paves the way for personalized nutrition that plays a key role in the prevention and treatment of chronic degenerative diseases.


2018 ◽  
Vol 12 ◽  
pp. 117955491877506 ◽  
Author(s):  
Maher Jedi ◽  
Graeme P Young ◽  
Susanne K Pedersen ◽  
Erin L Symonds

The genes BCAT1 and IKZF1 are hypermethylated in colorectal cancer (CRC), but little is known about how this relates to gene expression. This study assessed the relationship between methylation and gene expression of BCAT1 and IKZF1 in CRC and adjacent non-neoplastic tissues. The tissues were obtained at surgery from 36 patients diagnosed with different stages of CRC (stage I n = 8, stage II n = 13, stage III n = 10, stage IV n = 5). Methylated BCAT1 and IKZF1 were detected in 92% and 72% CRC tissues, respectively, with levels independent of stage ( P > .05). In contrast, only 31% and 3% of non-neoplastic tissues were methylated for BCAT1 and IKZF1, respectively ( P < .001). The IKZF1 messenger RNA (mRNA) expression was significantly lower in the cancer tissues compared with that of non-neoplastic tissues, whereas the BCAT1 mRNA levels were similar. The latter may be due to the BCAT1 polymerase chain reaction assay detecting more than 1 mRNA transcript. Further studies are warranted to establish the role of the epigenetic silencing of IKZF1 in colorectal oncogenesis.


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