Down-regulated gene expression of cold acclimated Poncirus trifoliata

2005 ◽  
Vol 85 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Can-Kui Zhang ◽  
Ping Lang ◽  
Robert C. Ebel ◽  
Fenny Dane ◽  
Narendra K Singh ◽  
...  

Citrus sp. are important commercial fruit crops throughout the world that are occasionally devastated by subfreezing temperatures. Poncirus trifoliata (maximum freeze tolerance of -26°C) is a close relative of commercial Citrus sp. (maximum freeze tolerance of -10°C) that has been used in breeding programs to develop more cold-hardy genotypes and as a rootstock to enhance freeze tolerance of the scion. Species with greater freeze tolerance vary in gene expression during cold acclimating temperatures. mRNA differential display (DDRT-PCR) and quantitative relative RT-PCR were used to study down regulation of gene expression in intact P. trifoliata exposed to a gradual cold acclimation regime to enhance our understanding of the mechanism that makes this specie so freeze tolerant. Six down-regulated genes were isolated and sequenced. These down-regulated genes showed high homology to the following known genes: chlorophyll a/b binding protein, photosystem II OEC 23, carbonic anhydrase, tumor related protein, pyrrolidone-carboxylate peptid ase and β-galactosidase. Photoprotection and the global control of gene expression related to photosynthesis appear to be important mechanisms for cold acclimation of P. trifoliata. Key words: Differential display, down-regulated genes, Poncirus trifoliata, cold acclimation and quantitative relative RT-PCR

2021 ◽  
Author(s):  
Martine Da Rocha ◽  
Caroline Bournaud ◽  
Julie Dazeniere ◽  
Peter Thorpe ◽  
Clement Pellegrin ◽  
...  

Root-knot nematodes are the major contributor to the crop losses caused by nematodes. Root-knot nematodes secrete effectors into the plant, derived from two sets of pharyngeal gland cells, to manipulate host physiology and immunity. Successful completion of the life cycle, involving successive molts from egg to adult, covers morphologically and functionally distinct stages and will require precise control of gene expression, including effectors. The details of how root-knot nematodes regulate transcription remain sparse. Here, we report a life stage-specific transcriptome of Meloidogyne incognita. Combined with an available annotated genome, we explore the spatio-temporal regulation of gene expression. We reveal gene expression clusters and predicted functions that accompany the major developmental transitions. Focusing on effectors, we identify a putative cis-regulatory motif associated with expression in the dorsal glands: providing an insight into effector regulation. We combine the presence of this motif with several other criteria to predict a novel set of putative dorsal gland effectors. Finally, we show this motif, and thereby its utility, is broadly conserved across the Meloidogyne genus and termed it Mel-DOG. Taken together, we provide the first genome-wide analysis of spatio-temporal gene expression in a root-knot nematode, and identify a new set of candidate effector genes that will guide future functional analyses.


1998 ◽  
Vol 80 (4) ◽  
pp. 307-321
Author(s):  
John E. Hesketh ◽  
M. Helena Vasconcelos ◽  
Giovanna Bermano

Nutrition has marked influences on gene expression and an understanding of the interaction between nutrients and gene expression is important in order to provide a basis for determining the nutritional requirements on an individual basis. The effects of nutrition can be exerted at many stages between transcription of the genetic sequence and production of a functional protein. This review focuses on the role of post-transcriptional control, particularly mRNA stability, translation and localization, in the interactions of nutrients with gene expression. The effects of both macronutrients and micronutrients on regulation of gene expression by post-transcriptional mechanisms are presented and the post-transcriptional regulation of specific genes of nutritional relevance (glucose transporters, transferrin, selenoenzymes, metallothionein, lipoproteins) is described in detail. The function of the regulatory signals in the untranslated regions of the mRNA is highlighted in relation to control of mRNA stability, translation and localization and the importance of these mRNA regions to regulation by nutrients is illustrated by reference to specific examples. The localization of mRNA by signals in the untranslated regions and its function in the spatial organization of protein synthesis is described; the potential of such mechanisms to play a key part in nutrient channelling and metabolic compartmentation is discussed. It is concluded that nutrients can influence gene expression through control of the regulatory signals in these untranslated regions and that the post-transcriptional regulation of gene expression by these mechanisms may influence nutritional requirements. It is emphasized that in studies of nutritional control of gene expression it is important not to focus only on regulation through gene promoters but also to consider the possibility of post-transcriptional control.


2010 ◽  
Vol 22 (1) ◽  
pp. 277
Author(s):  
L. A. Favetta ◽  
E. Van de Laar ◽  
W. A. King ◽  
J. LaMarre

The control of gene expression in the early embryo requires a highly regulated turnover of specific mRNA, particularly those of maternal origin, as the embryo becomes transcriptionally autonomous. In cattle, the period during which maternal transcripts persist can last 72 to 96 h or longer, suggesting a dynamic, regulated interplay between factors that protect transcripts before this point and those that subsequently facilitate decay. Some decay pathways for specific embryonic transcripts are now known, but many are not. In somatic cells, mRNA decay is often mediated by interactions between defined sequence elements (ARE) in the 3′ untranslated region of important target genes and specific RNA-binding proteins (AUBP) that promote or inhibit decay of the associated transcript. These have not been extensively characterized in embryos. We hypothesized that changes in the pattern of expression of one or several AUBP in the developing bovine embryo would support a role for these proteins in mRNA turnover and the control of gene expression. We, therefore, evaluated the expression of different AUBP (HuR, AUF1, TTP) in bovine oocytes and early embryos in vitro. Bovine oocytes obtained at slaughter were matured, fertilized, and cultured using standard protocols. Oocytes and embryos from different stages were either placed in Trizol for subsequent RNA isolation and RT-PCR analysis or fixed in 4% paraformaldehyde and subsequently processed for immunohistochemical detection of AUBP. Analysis by RT-PCR revealed that AUF1, an mRNA destabilizing protein, was expressed at all stages examined (immature oocyte, mature oocyte, 2 to 4 cells, 8 to 16 cells, morulae, and blastocyst) except in morulae. Another mRNA destabilizing protein, TTP, was expressed at the morula stage only. An mRNA stabilizing factor, HuR, was expressed at all stages except the morula. Immunohistochemical analysis revealed that the pattern of protein expression for AUF1 and TTP essentially mirrored that observed at the RNA level as detected by RT-PCR. Together, these results show that AUBP expression in the early bovine embryo is dynamic, with RNA-binding proteins present at all times during development and changes in expression evident at the morula stage. This suggests that modification of presynthesized (i.e. maternal) AUBP is likely to control mRNA decay during the maternal to embryonic transition (8-cell stage) and that the expression of TTP at the morula stage might mark the onset of embryonic control of mRNA stability. Research was supported by NSERC, OMAFRA, and the Canada Research Chairs Program.


2009 ◽  
Vol 192 (3) ◽  
pp. 819-833 ◽  
Author(s):  
Jennifer C. England ◽  
Barrett S. Perchuk ◽  
Michael T. Laub ◽  
James W. Gober

ABSTRACT In a developmental strategy designed to efficiently exploit and colonize sparse oligotrophic environments, Caulobacter crescentus cells divide asymmetrically, yielding a motile swarmer cell and a sessile stalked cell. After a relatively fixed time period under typical culture conditions, the swarmer cell differentiates into a replicative stalked cell. Since differentiation into the stalked cell type is irreversible, it is likely that environmental factors such as the availability of essential nutrients would influence the timing of the decision to abandon motility and adopt a sessile lifestyle. We measured two different parameters in nutrient-limited chemostat cultures, biomass concentration and the ratio of nonstalked to stalked cells, over a range of flow rates and found that nitrogen limitation significantly extended the swarmer cell life span. The transcriptional profiling experiments described here generate the first comprehensive picture of the global regulatory strategies used by an oligotroph when confronted with an environment where key macronutrients are sparse. The pattern of regulated gene expression in nitrogen- and carbon-limited cells shares some features in common with most copiotrophic organisms, but critical differences suggest that Caulobacter, and perhaps other oligotrophs, have evolved regulatory strategies to deal distinctly with their natural environments. We hypothesize that nitrogen limitation extends the swarmer cell lifetime by delaying the onset of a sequence of differentiation events, which when initiated by the correct combination of external environmental cues, sets the swarmer cell on a path to differentiate into a stalked cell within a fixed time period.


1999 ◽  
Vol 18 (6) ◽  
pp. 589-600 ◽  
Author(s):  
Hicham Zegzouti ◽  
Brian Jones ◽  
Pierre Frasse ◽  
Christel Marty ◽  
Beatrice Maitre ◽  
...  

2002 ◽  
Vol 21 (1) ◽  
pp. 043-050 ◽  
Author(s):  
R Rojas-Herrera ◽  
F Quiroz-Figueroa ◽  
M Monforte-González ◽  
L Sánchez-Teyer ◽  
V M Loyola-Vargas

2017 ◽  
Vol 114 (37) ◽  
pp. 9942-9947 ◽  
Author(s):  
Nicholas Lister ◽  
Galina Shevchenko ◽  
James L. Walshe ◽  
Jessica Groen ◽  
Per Johnsson ◽  
...  

RNA has been found to interact with chromatin and modulate gene transcription. In human cells, little is known about how long noncoding RNAs (lncRNAs) interact with target loci in the context of chromatin. We find here, using the phosphatase and tensin homolog (PTEN) pseudogene as a model system, that antisense lncRNAs interact first with a 5′ UTR-containing promoter-spanning transcript, which is then followed by the recruitment of DNA methyltransferase 3a (DNMT3a), ultimately resulting in the transcriptional and epigenetic control of gene expression. Moreover, we find that the lncRNA and promoter-spanning transcript interaction are based on a combination of structural and sequence components of the antisense lncRNA. These observations suggest, on the basis of this one example, that evolutionary pressures may be placed on RNA structure more so than sequence conservation. Collectively, the observations presented here suggest a much more complex and vibrant RNA regulatory world may be operative in the regulation of gene expression.


2009 ◽  
Vol 106 (17) ◽  
pp. 7028-7033 ◽  
Author(s):  
Zhe Ji ◽  
Ju Youn Lee ◽  
Zhenhua Pan ◽  
Bingjun Jiang ◽  
Bin Tian

The 3′ untranslated regions (3′ UTRs) of mRNAs containcis-acting elements for posttranscriptional regulation of gene expression. Here, we report that mouse genes tend to express mRNAs with longer 3′ UTRs as embryonic development progresses. This global regulation is controlled by alternative polyadenylation and coordinates with initiation of organogenesis and aspects of embryonic development, including morphogenesis, differentiation, and proliferation. Using myogenesis of C2C12 myoblast cells as a model, we recapitulated this process in vitro and found that 3′ UTR lengthening is likely caused by weakening of mRNA polyadenylation activity. Because alternative 3′ UTR sequences are typically longer and have higher AU content than constitutive ones, our results suggest that lengthening of 3′ UTR can significantly augment posttranscriptional control of gene expression during embryonic development, such as microRNA-mediated regulation.


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