scholarly journals Aspergillus nidulans wetA activates spore-specific gene expression.

1991 ◽  
Vol 11 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M A Marshall ◽  
W E Timberlake
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Aspergillus Nidulans ◽  
Gene Activation ◽  
Regulatory Function ◽  
Specific Gene ◽  
Coding Region ◽  
Vegetative Cells ◽  
Mutant Strains ◽  
Late Stages

The Aspergillus nidulans wetA gene is required for synthesis of cell wall layers that make asexual spores (conidia) impermeable. In wetA mutant strains, conidia take up water and autolyze rather than undergoing the final stages of maturation. wetA is activated during conidiogenesis by sequential expression of the brlA and abaA regulatory genes. To determine whether wetA regulates expression of other sporulation-specific genes, its coding region was fused to a nutritionally regulated promoter that permits gene activation in vegetative cells (hyphae) under conditions that suppress conidiation. Expression of wetA in hyphae inhibited growth and caused excessive branching. It did not lead to activation of brlA or abaA but did cause accumulation of transcripts from genes that are normally expressed specifically during the late stages of conidiation and whose mRNAs are stored in mature spores. Thus, wetA directly or indirectly regulates expression of some spore-specific genes. At least one gene (wA), whose mRNA does not occur in spores but rather accumulates in the sporogenous phialide cells, was activated by wetA, suggesting that wetA may have a regulatory function in these cells as well as in spores. We propose that wetA is responsible for activating a set of genes whose products make up the final two conidial wall layers or direct their assembly and through this activity is responsible for acquisition of spore dormancy.

Aspergillus nidulans wetA activates spore-specific gene expression

1991 ◽  
Vol 11 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M A Marshall ◽  
W E Timberlake
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Aspergillus Nidulans ◽  
Gene Activation ◽  
Regulatory Function ◽  
Specific Gene ◽  
Coding Region ◽  
Vegetative Cells ◽  
Mutant Strains ◽  
Late Stages

The Aspergillus nidulans wetA gene is required for synthesis of cell wall layers that make asexual spores (conidia) impermeable. In wetA mutant strains, conidia take up water and autolyze rather than undergoing the final stages of maturation. wetA is activated during conidiogenesis by sequential expression of the brlA and abaA regulatory genes. To determine whether wetA regulates expression of other sporulation-specific genes, its coding region was fused to a nutritionally regulated promoter that permits gene activation in vegetative cells (hyphae) under conditions that suppress conidiation. Expression of wetA in hyphae inhibited growth and caused excessive branching. It did not lead to activation of brlA or abaA but did cause accumulation of transcripts from genes that are normally expressed specifically during the late stages of conidiation and whose mRNAs are stored in mature spores. Thus, wetA directly or indirectly regulates expression of some spore-specific genes. At least one gene (wA), whose mRNA does not occur in spores but rather accumulates in the sporogenous phialide cells, was activated by wetA, suggesting that wetA may have a regulatory function in these cells as well as in spores. We propose that wetA is responsible for activating a set of genes whose products make up the final two conidial wall layers or direct their assembly and through this activity is responsible for acquisition of spore dormancy.

scholarly journals Transcriptional Changes in the Transition from Vegetative Cells to Asexual Development in the Model Fungus Aspergillus nidulans

2012 ◽  
Vol 12 (2) ◽  
pp. 311-321 ◽  
Author(s):  
Aitor Garzia ◽  
Oier Etxebeste ◽  
Julio Rodríguez-Romero ◽  
Reinhard Fischer ◽  
Eduardo A. Espeso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aspergillus Nidulans ◽  
Cell Types ◽  
Asexual Development ◽  
Primary Metabolism ◽  
Air Exposure ◽  
Vegetative Cells ◽  
Content Type ◽  
Zinc Cluster ◽  
Transcriptional Changes

ABSTRACTMorphogenesis encompasses programmed changes in gene expression that lead to the development of specialized cell types. In the model fungusAspergillus nidulans, asexual development involves the formation of characteristic cell types, collectively known as the conidiophore. With the aim of determining the transcriptional changes that occur upon induction of asexual development, we have applied massive mRNA sequencing to compare the expression pattern of 19-h-old submerged vegetative cells (hyphae) with that of similar hyphae after exposure to the air for 5 h. We found that the expression of 2,222 (20.3%) of the predicted 10,943A. nidulanstranscripts was significantly modified after air exposure, 2,035 being downregulated and 187 upregulated. The activation during this transition of genes that belong specifically to the asexual developmental pathway was confirmed. Another remarkable quantitative change occurred in the expression of genes involved in carbon or nitrogen primary metabolism. Genes participating in polar growth or sexual development were transcriptionally repressed, as were those belonging to the HogA/SakA stress response mitogen-activated protein (MAP) kinase pathway. We also identified significant expression changes in several genes purportedly involved in redox balance, transmembrane transport, secondary metabolite production, or transcriptional regulation, mainly binuclear-zinc cluster transcription factors. Genes coding for these four activities were usually grouped in metabolic clusters, which may bring regulatory implications for the induction of asexual development. These results provide a blueprint for further stage-specific gene expression studies during conidiophore development.

scholarly journals Expression profiles of cell-wall related genes vary broadly between two common maize inbreds during stem development

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Bryan W. Penning ◽  
Tânia M. Shiga ◽  
John F. Klimek ◽  
Philip J. SanMiguel ◽  
Jacob Shreve ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Genetic Variation ◽  
Secondary Wall ◽  
Expression Profiles ◽  
Gene Families ◽  
Grass Species ◽  
Specific Gene ◽  
Maize Inbreds ◽  
Stem Development

Abstract Background The cellular machinery for cell wall synthesis and metabolism is encoded by members of large multi-gene families. Maize is both a genetic model for grass species and a potential source of lignocellulosic biomass from crop residues. Genetic improvement of maize for its utility as a bioenergy feedstock depends on identification of the specific gene family members expressed during secondary wall development in stems. Results High-throughput sequencing of transcripts expressed in developing rind tissues of stem internodes provided a comprehensive inventory of cell wall-related genes in maize (Zea mays, cultivar B73). Of 1239 of these genes, 854 were expressed among the internodes at ≥95 reads per 20 M, and 693 of them at ≥500 reads per 20 M. Grasses have cell wall compositions distinct from non-commelinid species; only one-quarter of maize cell wall-related genes expressed in stems were putatively orthologous with those of the eudicot Arabidopsis. Using a slope-metric algorithm, five distinct patterns for sub-sets of co-expressed genes were defined across a time course of stem development. For the subset of genes associated with secondary wall formation, fifteen sequence motifs were found in promoter regions. The same members of gene families were often expressed in two maize inbreds, B73 and Mo17, but levels of gene expression between them varied, with 30% of all genes exhibiting at least a 5-fold difference at any stage. Although presence-absence and copy-number variation might account for much of these differences, fold-changes of expression of a CADa and a FLA11 gene were attributed to polymorphisms in promoter response elements. Conclusions Large genetic variation in maize as a species precludes the extrapolation of cell wall-related gene expression networks even from one common inbred line to another. Elucidation of genotype-specific expression patterns and their regulatory controls will be needed for association panels of inbreds and landraces to fully exploit genetic variation in maize and other bioenergy grass species.

scholarly journals Altered Enhancer and Promoter Usage Leads to Differential Gene Expression in the Normal and Failed Human Heart

2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Anthony M. Gacita ◽  
Lisa Dellefave-Castillo ◽  
Patrick G.T. Page ◽  
David Y. Barefield ◽  
J. Andrew Wasserstrom ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Ventricular Remodeling ◽  
Regulatory Function ◽  
Specific Gene ◽  
Data Set ◽  
Promoter Usage ◽  
Additional Support ◽  
Cap Analysis ◽  
Genetic Contributions

Background: The failing heart is characterized by changes in gene expression. However, the regulatory regions of the genome that drive these gene expression changes have not been well defined in human hearts. Methods: To define genome-wide enhancer and promoter use in heart failure, cap analysis of gene expression sequencing was applied to 3 healthy and 4 failed human hearts to identify promoter and enhancer regions used in left ventricles. Healthy hearts were derived from donors unused for transplantation and failed hearts were obtained as discarded tissue after transplantation. Results: Cap analysis of gene expression sequencing identified a combined potential for ≈23 000 promoters and ≈5000 enhancers active in human left ventricles. Of these, 17 000 promoters and 1800 enhancers had additional support for their regulatory function. Comparing promoter usage between healthy and failed hearts highlighted promoter shifts which altered aminoterminal protein sequences. Enhancer usage between healthy and failed hearts identified a majority of differentially used heart failure enhancers were intronic and primarily localized within the first intron, revealing this position as a common feature associated with tissue-specific gene expression changes in the heart. Conclusions: This data set defines the dynamic genomic regulatory landscape underlying heart failure and serves as an important resource for understanding genetic contributions to cardiac dysfunction. Additionally, regulatory changes contributing to heart failure are attractive therapeutic targets for controlling ventricular remodeling and clinical progression.

scholarly journals A Floxed exon (Flexon) approach to Cre-mediated conditional gene expression

2021 ◽  
Author(s):  
Justin M Shaffer ◽  
Iva Greenwald
Keyword(s):  
Gene Expression ◽  
Specific Protein ◽  
Specific Gene ◽  
Coding Region ◽  
Specific Expression ◽  
Control Of Gene Expression ◽  
Tissue Specific ◽  
Nonsense Mediated Decay ◽  
Conditional Gene Expression ◽  
Stop Cassette

Conditional gene expression allows for genes to be manipulated and lineages to be marked during development. In the established "lox-stop-lox" approach, Cre-mediated tissue-specific gene expression is achieved by excising the stop cassette, a lox-flanked translational stop that is inserted into the 5' untranslated region of a gene to halt its expression. Although lox-stop-lox has been successfully used in many experimental systems, the design of traditional stop cassettes also has common issues and limitations. Here, we describe the Floxed exon (Flexon), a stop cassette within an artificial exon that can be inserted flexibly into the coding region of any gene to cause premature termination of translation and nonsense-mediated decay of the mRNA. We demonstrate its efficacy in C. elegans by showing that, when promoters that cause weak and/or transient cell-specific expression are used to drive Cre in combination with a gfp(flexon) transgene, strong and sustained expression is obtained in specific lineages. We also describe several potential additional applications for using Flexon for developmental studies, including more precise control of gene expression using intersectional methods, tissue-specific protein degradation or RNAi, and generation of genetic mosaics. The Flexon approach should be feasible in any system where any site-specific recombination-based method may be applied.

Cell type-specific gene expression underpins remodelling of cell wall pectin in exocarp and cortex during apple fruit development

2019 ◽  
Vol 70 (21) ◽  
pp. 6085-6099
Author(s):  
Patrick P Collins ◽  
Erin M O’donoghue ◽  
Ria Rebstock ◽  
Heather R Tiffin ◽  
Paul W Sutherland ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Fruit Development ◽  
Cell Types ◽  
Apple Fruit ◽  
Epidermal Cells ◽  
Specific Gene ◽  
Cell Type ◽  
Specific Gene Expression ◽  
Cell Type Specific

Young apple epidermal cells process cell wall pectic arabinan and galactan side chains different from other cell types, resulting in debranched linear arabinans and the absence of galactans.

The Therapeutic Potential of Small Activating RNAs for Colorectal Carcinoma

2019 ◽  
Vol 19 (3) ◽  
pp. 140-146
Author(s):  
Bin Zheng ◽  
QingYun Mai ◽  
JinXing Jiang ◽  
QinQin Zhou
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Gene Activation ◽  
Specific Gene ◽  
Dependent Manner ◽  
Master Regulators ◽  
High Incidence ◽  
Underlying Mechanisms

Small double-strand RNAs have been recognized as master regulators of gene expression. In contrast to the evolutionary conserved RNA interference machinery, which degrades or inhibits the translation of target mRNAs, small activating RNA (saRNA) activates the specific gene in a target dependent manner through a similar mechanism as RNAi. Recently, saRNA mediated expression regulation of specific genes has been extensively studied in cancer researches. Of particular interest is the application of the RNA mediated gene activation within colorectal cancer (CRC) development, due to the high incidence of the CRC. In this review, we summarize the current knowledge of saRNA mediated genetic activation and its underlying mechanisms. Furthermore, we highlight the advantages of the utilization of saRNAs induced gene expression as an investigating tool in colorectal cancer research. Finally, the possibility and the challenge of the saRNA application as a potential therapy for colorectal cancer are addressed.

scholarly journals Regulation of Id3 cell cycle function by Cdk-2-dependent phosphorylation.

1997 ◽  
Vol 17 (12) ◽  
pp. 6815-6821 ◽  
Author(s):  
R W Deed ◽  
E Hara ◽  
G T Atherton ◽  
G Peters ◽  
J D Norton
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Complex Formation ◽  
S Phase ◽  
Regulatory Function ◽  
Specific Gene ◽  
Wild Type ◽  
E Box ◽  
Phase Entry

The functions of basic helix-loop-helix (bHLH) transcription factors in activating differentiation-linked gene expression and in inducing G1 cell cycle arrest are negatively regulated by members of the Id family of HLH proteins. These bHLH antagonists are induced during a mitogenic signalling response, and they function by sequestering their bHLH targets in inactive heterodimers that are unable to bind to specific gene regulatory (E box) sequences. Recently, cyclin E-Cdk2- and cyclin A-Cdk2-dependent phosphorylation of a single conserved serine residue (Ser5) in Id2 has been shown to occur during late G1-to-S phase transition of the cell cycle, and this neutralizes the function of Id2 in abrogating E-box-dependent bHLH homo- or heterodimer complex formation in vitro (E. Hara, M. Hall, and G. Peters, EMBO J. 16:332-342, 1997). We now show that an analogous cell-cycle-regulated phosphorylation of Id3 alters the specificity of Id3 for abrogating both E-box-dependent bHLH homo- or heterodimer complex formation in vitro and E-box-dependent reporter gene function in vivo. Furthermore, compared with wild-type Id3, an Id3 Asp5 mutant (mimicking phosphorylation) is unable to promote cell cycle S phase entry in transfected fibroblasts, whereas an Id3 Ala5 mutant (ablating phosphorylation) displays an activity significantly greater than that of wild-type Id3 protein. Cdk2-dependent phosphorylation therefore provides a switch during late G1-to-S phase that both nullifies an early G1 cell cycle regulatory function of Id3 and modulates its target bHLH specificity. These data also demonstrate that the ability of Id3 to promote cell cycle S phase entry is not simply a function of its ability to modulate bHLH heterodimer-dependent gene expression and establish a biologically important mechanism through which Cdk2 and Id-bHLH functions are integrated in the coordination of cell proliferation and differentiation.

scholarly journals A Chinese Herbal Decoction, Danggui Buxue Tang, Stimulates Proliferation, Differentiation and Gene Expression of Cultured Osteosarcoma Cells: Genomic Approach to Reveal Specific Gene Activation

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Roy C. Y. Choi ◽  
Qiu T. Gao ◽  
Anna W. H. Cheung ◽  
Judy T. T. Zhu ◽  
Faye T. C. Lau ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Activation ◽  
Specific Gene ◽  
Danggui Buxue Tang ◽  
Radix Angelicae Sinensis ◽  
Chinese Herbal ◽  
Cell Proliferation And Differentiation ◽  
Herbal Decoction ◽  
Regulated Gene Expression ◽  
Angelicae Sinensis

Danggui Buxue Tang (DBT), a Chinese herbal decoction used to treat ailments in women, contains Radix Astragali (Huangqi; RA) and Radix Angelicae Sinensis (Danggui; RAS). When DBT was applied onto cultured MG-63 cells, an increase of cell proliferation and differentiation of MG-63 cell were revealed: both of these effects were significantly higher in DBT than RA or RAS extract. To search for the biological markers that are specifically regulated by DBT, DNA microarray was used to reveal the gene expression profiling of DBT in MG-63 cells as compared to that of RA- or RAS-treated cells. Amongst 883 DBT-regulated genes, 403 of them are specifically regulated by DBT treatment, including CCL-2, CCL-7, CCL-8, and galectin-9. The signaling cascade of this DBT-regulated gene expression was also elucidated in cultured MG-63 cells. The current results reveal the potential usage of this herbal decoction in treating osteoporosis and suggest the uniqueness of Chinese herbal decoction that requires a well-defined formulation. The DBT-regulated genes in the culture could serve as biological responsive markers for quality assurance of the herbal preparation.

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