New opportunities to dissect and manipulate plant processes

1993 ◽  
Vol 339 (1288) ◽  
pp. 199-206 ◽  

The use of transgenic plants has become a standard tool of experimental plant biology and is changing many approaches to plant improvement. The technology has greatly expanded the range of methods available to isolate and identify new plants genes, and has permitted great strides in understanding the mechanisms which regulate gene expression. In addition, the ability to use cloned genes to alter the functional expression of the gene in transgenic plants has created entirely novel opportunities to examine the biological role of virtually any cellular constituent.

Author(s):  
Charlotte A.M. Cecil

The biopsychosocial (BPS) model of psychiatry has had a major impact on our modern conceptualization of mental illness as a complex, multi-determined phenomenon. Yet, interdisciplinary BPS work remains the exception, rather than the rule in psychiatry. It has been suggested that this may stem in part from a failure of the BPS model to clearly delineate the mechanisms through which biological, psychological, and social factors co-act in the development of mental illness. This chapter discusses how epigenetic processes that regulate gene expression, such as DNA methylation, are fast emerging as a candidate mechanism for BPS interactions, with potentially widespread implications for the way that psychiatric disorders are understood, assessed, and, perhaps in future, even treated.


2020 ◽  
Vol 295 (26) ◽  
pp. 8736-8745 ◽  
Author(s):  
Akihiko Sakamoto ◽  
Yusuke Terui ◽  
Takeshi Uemura ◽  
Kazuei Igarashi ◽  
Keiko Kashiwagi

Polyamines regulate gene expression in Escherichia coli by translationally stimulating mRNAs encoding global transcription factors. In this study, we focused on histone acetylation, one of the mechanisms of epigenetic regulation of gene expression, to attempt to clarify the role of polyamines in the regulation of gene expression in eukaryotes. We found that activities of histone acetyltransferases in both the nucleus and cytoplasm decreased significantly in polyamine-reduced mouse mammary carcinoma FM3A cells. Although protein levels of histones H3 and H4 did not change in control and polyamine-reduced cells, acetylation of histones H3 and H4 was greatly decreased in the polyamine-reduced cells. Next, we used control and polyamine-reduced cells to identify histone acetyltransferases whose synthesis is stimulated by polyamines. We found that polyamines stimulate the translation of histone acetyltransferases GCN5 and HAT1. Accordingly, GCN5- and HAT1-catalyzed acetylation of specific lysine residues on histones H3 and H4 was stimulated by polyamines. Consistent with these findings, transcription of genes required for cell proliferation was enhanced by polyamines. These results indicate that polyamines regulate gene expression by enhancing the expression of the histone acetyltransferases GCN5 and HAT1 at the level of translation. Mechanistically, polyamines enhanced the interaction of microRNA-7648-5p (miR-7648-5p) with the 5′-UTR of GCN5 mRNA, resulting in stimulation of translation due to the destabilization of the double-stranded RNA (dsRNA) between the 5′-UTR and the ORF of GCN5 mRNA. Because HAT1 mRNA has a short 5′-UTR, polyamines may enhance initiation complex formation directly on this mRNA.


1994 ◽  
Vol 91 (3) ◽  
pp. 461-467 ◽  
Author(s):  
Pilar Colorado ◽  
Antonio Rodriguez ◽  
Gregorio Nicolas ◽  
Dolores Rodriguez

MicroRNA ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ling Lin ◽  
Kebin Hu

: MicroRNAs (miRNAs) are small non-coding RNAs (19~25 nucleotides) that regulate gene expression at a post-transcriptional level through repression of mRNA translation or mRNA decay. miR-147, which was initially discovered in mouse spleen and macrophages, has been shown to correlate with coronary atherogenesis and inflammatory bowel disease and modulate macrophage functions and inflammation through TLR-4. The altered miR-147 level has been shown in various human diseases, including infectious disease, cancer, cardiovascular disease, a neurodegenerative disorder, etc. This review will focus on the current understanding regarding the role of miR-147 in inflammation and diseases.


2019 ◽  
Vol 20 (12) ◽  
pp. 2922 ◽  
Author(s):  
Francesca Cirillo ◽  
Cecilia Catellani ◽  
Chiara Sartori ◽  
Pietro Lazzeroni ◽  
Sergio Amarri ◽  
...  

Obesity is associated with insulin resistance and low-grade inflammation. Insulin resistance is a risk factor for cancer. A recent chapter in epigenetics is represented by microRNAs (miRNAs), which post-transcriptionally regulate gene expression. Dysregulated miRNA profiles have been associated with diseases including obesity and cancer. Herein we report dysregulated miRNAs in obesity both in animal models and in humans, and we also document dysregulated miRNAs in colorectal cancer (CRC), as example of an obesity-related cancer. Some of the described miRNAs are found to be similarly dysregulated both in obesity, insulin resistance (IR), and CRC. Thus, we present miRNAs as a potential molecular link between obesity and CRC onset and development, giving a new perspective on the role of miRNAs in obesity-associated cancers.


2020 ◽  
Vol 6 (36) ◽  
pp. eabb0333
Author(s):  
Sari Kassem ◽  
Paolo Ferrari ◽  
Amanda L. Hughes ◽  
Julien Soudet ◽  
Oliver J. Rando ◽  
...  

Transcription in eukaryotes correlates with major chromatin changes, including the replacement of old nucleosomal histones by new histones at the promoters of genes. The role of these histone exchange events in transcription remains unclear. In particular, the causal relationship between histone exchange and activator binding, preinitiation complex (PIC) assembly, and/or subsequent transcription remains unclear. Here, we provide evidence that histone exchange at gene promoters is not simply a consequence of PIC assembly or transcription but instead is mediated by activators. We further show that not all activators up-regulate gene expression by inducing histone turnover. Thus, histone exchange does not simply correlate with transcriptional activity, but instead reflects the mode of action of the activator. Last, we show that histone turnover is not only associated with activator function but also plays a role in transcriptional repression at the histone loci.


2017 ◽  
Vol 37 (5) ◽  
Author(s):  
Ling-Ping Zhu ◽  
Yun-Jie He ◽  
Jun-Chen Hou ◽  
Xiu Chen ◽  
Si-Ying Zhou ◽  
...  

Circular RNAs (circRNAs) are recently regarded as a naturally forming family of widespread and diverse endogenous noncoding RNAs (ncRNAs) that may regulate gene expression in mammals. At present, above 30000 circRNAs have already been found, with their unique structures to maintain stability more easily than linear RNAs. Several previous literatures stressed on the important role of circRNAs, whose expression was relatively correlated with patients’ clinical characteristics and grade, in the carcinogenesis of cancer. CircRNAs are involved in many regulatory bioprocesses of malignance, including cell cycle, tumorigenesis, invasion, metastasis, apoptosis, vascularization, through adsorbing RNA as a sponge, binding to RNA-binding protein (RBP), modulating transcription, or influencing translation. Therefore, it is inevitable to further study the interactions between circRNAs and tumors and to develop novel circRNAs as molecular markers or potential targets, which will provide promising applications in early diagnosis, therapeutic evaluation, prognosis prediction of tumors and even gene therapy for tumors.


1998 ◽  
Vol 10 (8) ◽  
pp. 639 ◽  
Author(s):  
Ian Wilmut ◽  
Lorraine Young ◽  
Keith H.S. Campbell

Revolutionary opportunities in biology, medicine and agriculture arise from the observation that offspring are obtained after nuclear transfer if somatic donor cells are induced to become quiescent. Exploitation of many of these opportunities will depend upon optimizing procedures for nuclear transfer. This may come about through an understanding of the means by which factors in the oocyte cytoplasm act upon the DNA of the transferred nucleus to regulate gene expression. Similarly, research will extend the procedure to other species. This technology may be used for embryo production, the introduction of genetic change and the derivation of cells needed to treat human diseases. Groups of genetically identical animals will be used in research to control genetic variation and to allow transfer of cells between individuals. In agriculture, production of a small number of clones will separate genetic and environmental effects, whereas production of larger numbers of offspring will disseminate genetic improvement from nucleus herds. Precise genetic modification will be achieved by site specific recombination in the donor cells before nuclear transfer. In all mammals it will become possible to define the role of any gene product and to analyse the mechanisms that regulate gene expression. Medical uses of these techniques will include the production of proteins needed to treat disease and the supply of organs such as hearts, livers and kidneys from pigs. As genome mapping projects identify loci associated with traits of commercial importance in agriculture then gene targeting will be used to study this effect. Finally, cells capable of differentiation into any of the tissues of a patient will provide treatment for diseases reflecting damage to a specific cell population that neither repairs nor replaces itself.


MicroRNA ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Rebecca Mathew ◽  
Valentina Mattei ◽  
Muna Al Hashmi ◽  
Sara Tomei

MicroRNAs are RNA molecules of ~22 nt length that regulate gene expression posttranscriptionally. The role of miRNAs has been reported in many cellular processes including apoptosis, cell differentiation, development and proliferation. The dysregulated expression of miRNAs has been proposed as a biomarker for the diagnosis, onset and prognosis of human diseases. The utility of miRNA profiles to identify and discriminate patients from healthy individuals is highly dependent on the sensitivity and specificity of the technologies used for their detection and the quantity and quality of starting material. In this review, we present an update of the current technologies for the extraction, QC assessment and detection of miRNAs with special focus to the most recent methods, discussing their advantages as well as their shortcomings.


2010 ◽  
Vol 32 (5) ◽  
pp. 18-20
Author(s):  
Mary G. Goll

Proper regulation of gene expression is essential for the development and survival of every organ ism. Epigenetic modifications provide a way for cells to regulate gene expression and to propagate expression states heritably through cell division. Given the brain's complexity, it is not surprising that epigenetic regulation is essential for both normal development and maintenance of homoeostasis of this organ. New data suggest that the role of epigenetic regulation in the brain may extend much further, influencing both the ways neurons organize their networks in response to new experiences and the resultant behaviours. Such studies highlight the relevance of epigenetic regulation for neu rodevelopmental and neuropsychiatric disease.


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