Overgrowth mutants determine the causal role of gibberellin GA2oxidaseA13 in Rht12 dwarfism of wheat

2020 ◽  
Vol 71 (22) ◽  
pp. 7171-7178
Author(s):  
Wolfram Buss ◽  
Brett A Ford ◽  
Eloise Foo ◽  
Wendelin Schnippenkoetter ◽  
Philippa Borrill ◽  
...  
Keyword(s):  
Dwarfing Genes ◽  
Loss Of Function ◽  
Dwarf Phenotype ◽  
Coleoptile Length ◽  
Oxidase Gene ◽  
Dwarfing Gene ◽  
Chromosome 5A ◽  
Agronomic Potential ◽  
Suppressor Mutants

Abstract The induced dwarf mutant Rht12 was previously shown to have agronomic potential to replace the conventional DELLA mutants Rht-B1b/Rht-D1b in wheat. The Rht12 dwarfing gene is not associated with reduced coleoptile length (unlike the DELLA mutants) and it is dominant, characteristics which are shared with the previously characterized dwarfing genes Rht18 and Rht14. Using the Rht18/Rht14 model, a gibberellin (GA) 2-oxidase gene was identified in the Rht12 region on chromosome 5A. A screen for suppressor mutants in the Rht12 background identified tall overgrowth individuals that were shown to contain loss-of-function mutations in GA2oxidaseA13, demonstrating the role of this gene in the Rht12 dwarf phenotype. It was concluded that Rht12, Rht18, and Rht14 share the same height-reducing mechanism through the increased expression of GA 2-oxidase genes. Some of the overgrowth mutants generated in this study were semi-dwarf and taller than the original Rht12 dwarf, providing breeders with new sources of agronomically useful dwarfism.

Quantitative trait loci on chromosome 4B for coleoptile length and early vigour in wheat (Triticum aestivum L.)

2001 ◽  
Vol 52 (12) ◽  
pp. 1221 ◽  
Author(s):  
G. J. Rebetzke ◽  
R. Appels ◽  
A. D. Morrison ◽  
R. A. Richards ◽  
G. McDonald ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Leaf Area ◽  
Plant Height ◽  
Quantitative Trait ◽  
Dwarfing Genes ◽  
Genotypic Variance ◽  
Coleoptile Length ◽  
Dwarfing Gene ◽  
Early Vigour ◽  
Trait Loci

The Norin-10 dwarfing genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), are commonly used to reduce plant height and increase grain yield in wheat breeding programs. These dwarfing genes lower sensitivity of vegetative tissue to endogenous gibberellin to reduce cell and subsequent stem elongation. This reduction in cell elongation capacity reportedly results in a concomitant reduction in coleoptile length and early vigour (leaf area) thereby affecting seedling establishment and growth. A detailed genetic map from a cross between tall Halberd (Rht-B1a) and semidwarf Cranbrook (Rht-B1b) wheat cultivars was used to assess genetic factors affecting seedling growth. Parental and 150 doubled haploid progeny lines were characterised for seedling and height-related traits in controlled and field environments. Genotypic variation was large and predominantly under additive genetic control with evidence for transgressive segregation for some traits. Narrow-sense heritabilities were moderate to high (h2 = 0.31–0.91) indicating a strong genetic basis for differences between progeny. Molecular marker analyses identified a number of significant (P < 0.05) quantitative trait loci (QTL) for each trait. A major QTL, mapping directly to the Rht-B1 locus on chromosome arm 4BS, accounted for up to 49% of the genotypic variance in peduncle length and plant height, and 27–45% of the genotypic variance in coleoptile length across different temperatures. Another QTL, located close to the RFLP marker XksuC2 on the long arm of chromosome 4B, accounted for 15–27% of the genotypic variance in coleoptile length. The influence of the XksuC2-linked QTL on coleoptile length was greatest at 19˚C and decreased with cooler temperatures. The same QTL affected reductions in leaf size, and both coleoptile tiller size and presence to affect overall seedling vigour. There was also some evidence for epistatic interactions influencing coleoptile tiller growth. Reductions in plant size at the Rht-B1b and XksuC2 loci were associated with presence of the Cranbrook 4B allele. The negative genetic effect of the Rht-B1b dwarfing gene on early growth of wheat confirms phenotypic evidence of a pleiotropic effect of Rht-B1b on establishment and early vigour. Genetic increases in coleoptile length and early leaf area development are likely to be limited in wheat populations containing the Rht-B1b dwarfing gene.

scholarly journals A family harboring an MLKL loss of function variant implicates impaired necroptosis in diabetes

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Joanne M. Hildebrand ◽  
Bernice Lo ◽  
Sara Tomei ◽  
Valentina Mattei ◽  
Samuel N. Young ◽  
...  
Keyword(s):  
Potential Role ◽  
Autosomal Dominant ◽  
Inflammatory Diseases ◽  
Diabetic Patients ◽  
Incomplete Penetrance ◽  
Loss Of Function ◽  
Healthy Sibling ◽  
Dominant Disease ◽  
Terminal Effector

AbstractMaturity-onset diabetes of the young, MODY, is an autosomal dominant disease with incomplete penetrance. In a family with multiple generations of diabetes and several early onset diabetic siblings, we found the previously reported P33T PDX1 damaging mutation. Interestingly, this substitution was also present in a healthy sibling. In contrast, a second very rare heterozygous damaging mutation in the necroptosis terminal effector, MLKL, was found exclusively in the diabetic family members. Aberrant cell death by necroptosis is a cause of inflammatory diseases and has been widely implicated in human pathologies, but has not yet been attributed functions in diabetes. Here, we report that the MLKL substitution observed in diabetic patients, G316D, results in diminished phosphorylation by its upstream activator, the RIPK3 kinase, and no capacity to reconstitute necroptosis in two distinct MLKL−/− human cell lines. This MLKL mutation may act as a modifier to the P33T PDX1 mutation, and points to a potential role of impairment of necroptosis in diabetes. Our findings highlight the importance of family studies in unraveling MODY’s incomplete penetrance, and provide further support for the involvement of dysregulated necroptosis in human disease.

scholarly journals Non-productive angiogenesis disassembles Aß plaque-associated blood vessels

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria I. Alvarez-Vergara ◽  
Alicia E. Rosales-Nieves ◽  
Rosana March-Diaz ◽  
Guiomar Rodriguez-Perinan ◽  
Nieves Lara-Ureña ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Molecular Signature ◽  
Loss Of Function ◽  
Local Loss ◽  
Microglial Phagocytosis ◽  
Vascular Phenotype ◽  
Cerebral Microvasculature ◽  
Vascular Component

AbstractThe human Alzheimer’s disease (AD) brain accumulates angiogenic markers but paradoxically, the cerebral microvasculature is reduced around Aß plaques. Here we demonstrate that angiogenesis is started near Aß plaques in both AD mouse models and human AD samples. However, endothelial cells express the molecular signature of non-productive angiogenesis (NPA) and accumulate, around Aß plaques, a tip cell marker and IB4 reactive vascular anomalies with reduced NOTCH activity. Notably, NPA induction by endothelial loss of presenilin, whose mutations cause familial AD and which activity has been shown to decrease with age, produced a similar vascular phenotype in the absence of Aß pathology. We also show that Aß plaque-associated NPA locally disassembles blood vessels, leaving behind vascular scars, and that microglial phagocytosis contributes to the local loss of endothelial cells. These results define the role of NPA and microglia in local blood vessel disassembly and highlight the vascular component of presenilin loss of function in AD.

scholarly journals CircHIPK3 regulates the autophagy and apoptosis of hypoxia/reoxygenation-stimulated cardiomyocytes via the miR-20b-5p/ATG7 axis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhimei Qiu ◽  
Yan Wang ◽  
Weiwei Liu ◽  
Chaofu Li ◽  
Ranzun Zhao ◽  
...  
Keyword(s):  
Cell Injury ◽  
Ischemia Reperfusion ◽  
Circular Rna ◽  
Control Group ◽  
Loss Of Function ◽  
Cardiomyocyte Autophagy ◽  
Myocardial Ischemia Reperfusion ◽  
Injury Research ◽  
Hypoxia Reoxygenation

AbstractAutophagy and apoptosis are involved in myocardial ischemia/reperfusion (I/R) injury. Research indicates that circular RNA HIPK3 (circHIPK3) is crucial to cell autophagy and apoptosis in various cancer types. However, the role of circHIPK3 in the regulation of cardiomyocyte autophagy and apoptosis during I/R remains unknown. Our study aimed to examine the regulatory effect of circHIPK3 during myocardial I/R and investigate its mechanism in cardiomyocyte autophagy and apoptosis. Methods and results. The expression of circHIPK3 was upregulated during myocardial I/R injury and hypoxia/reoxygenation (H/R) injury of cardiomyocytes. To study the potential role of circHIPK3 in myocardial H/R injury, we performed gain-of-function and loss-of-function analyses of circHIPK3 in cardiomyocytes. Overexpression of circHIPK3 significantly promoted H/R-induced cardiomyocyte autophagy and cell injury (increased intracellular reactive oxygen species (ROS) and apoptosis) compared to those in the control group, while silencing of circHIPK3 showed the opposite effect. Further research found that circHIPK3 acted as an endogenous miR-20b-5p sponge to sequester and inhibit miR-20b-5p activity, resulting in increased ATG7 expression. In addition, miR-20b-5p inhibitors reversed the decrease in ATG7 induced by silencing circHIPK3. Conclusions. CircHIPK3 can accelerate cardiomyocyte autophagy and apoptosis during myocardial I/R injury through the miR-20b-5p/ATG7 axis. These data suggest that circHIPK3 may serve as a potential therapeutic target for I/R.

scholarly journals MBRS-17. EXAMINING THE ROLE OF LHX9 IN GROUP 3 MEDULLOBLASTOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii401-iii401
Author(s):  
Sarah Injac ◽  
L Frank Huang ◽  
Stephen Mack ◽  
Frank Braun ◽  
Yuchen Du ◽  
...  
Keyword(s):  
Drug Repositioning ◽  
Single Agent ◽  
Xenograft Model ◽  
Cell Killing ◽  
Rna Seq ◽  
Loss Of Function ◽  
Novel Treatments ◽  
Novel Approach ◽  
Group 3

Abstract Medulloblastoma (MB) is the most common malignant brain tumor of childhood. Despite major advances in our understanding of the biology of MB, novel treatments remain urgently needed. Using a chemical-genomics driven drug repositioning strategy, we identified the cardiac glycoside family of compounds as potential treatments for Group 3 MB. We subsequently demonstrated that single-agent treatment with digoxin prolongs survival in a patient-derived xenograft model (PDOX) of Group 3 MB to a degree comparable to radiation therapy, a mainstay in the treatment of MB. Finally, we examined the mechanism of digoxin-mediated cell killing using RNA-seq. This work identified LHX9, a member of the LIM homeobox family of transcription factors, as the gene most significantly down-regulated following treatment (Huang and Injac et al, Sci Trans Medicine, 2018). Homologs of LHX9 play key roles in cerebellar development via spatially and temporally restricted expression and LHX9 has been proposed as a core transcription factor (TF) in the regulatory circuitry of Group 3 tumors. Loss of function of other core TFs has been shown to impact MB growth. The role of LHX9 in MB, however, has not been previously experimentally evaluated. We now report that knockdown of LHX9 in MB-derived cell lines results in marked growth inhibition raising the possibility that loss of LHX9 plays a major role in digoxin-mediated cell killing and that LHX9 represents a key dependency required for the growth of Group 3 MB. Clinical targeting of core TFs would represent a novel approach to targeting this devastating disease.

scholarly journals Mutation ofRv2887, amarR-Like Gene, Confers Mycobacterium tuberculosis Resistance to an Imidazopyridine-Based Agent

2015 ◽  
Vol 59 (11) ◽  
pp. 6873-6881 ◽  
Author(s):  
Kathryn Winglee ◽  
Shichun Lun ◽  
Marco Pieroni ◽  
Alan Kozikowski ◽  
William Bishai
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Efflux Pump ◽  
Transcriptional Regulator ◽  
Cross Resistance ◽  
Loss Of Function ◽  
Strong Activity ◽  
Content Type ◽  
Novel Drug

ABSTRACTDrug resistance is a major problem inMycobacterium tuberculosiscontrol, and it is critical to identify novel drug targets and new antimycobacterial compounds. We have previously identified an imidazo[1,2-a]pyridine-4-carbonitrile-based agent, MP-III-71, with strong activity againstM. tuberculosis. In this study, we evaluated mechanisms of resistance to MP-III-71. We derived three independentM. tuberculosismutants resistant to MP-III-71 and conducted whole-genome sequencing of these mutants. Loss-of-function mutations inRv2887were common to all three MP-III-71-resistant mutants, and we confirmed the role ofRv2887as a gene required for MP-III-71 susceptibility using complementation. The Rv2887 protein was previously unannotated, but domain and homology analyses suggested it to be a transcriptional regulator in the MarR (multiple antibiotic resistance repressor) family, a group of proteins first identified inEscherichia colito negatively regulate efflux pumps and other mechanisms of multidrug resistance. We found that two efflux pump inhibitors, verapamil and chlorpromazine, potentiate the action of MP-III-71 and that mutation ofRv2887abrogates their activity. We also used transcriptome sequencing (RNA-seq) to identify genes which are differentially expressed in the presence and absence of a functional Rv2887 protein. We found that genes involved in benzoquinone and menaquinone biosynthesis were repressed by functional Rv2887. Thus, inactivating mutations ofRv2887, encoding a putative MarR-like transcriptional regulator, confer resistance to MP-III-71, an effective antimycobacterial compound that shows no cross-resistance to existing antituberculosis drugs. The mechanism of resistance ofM. tuberculosisRv2887mutants may involve efflux pump upregulation and also drug methylation.

scholarly journals COUP-TFII Regulates Human Endometrial Stromal Genes Involved in Inflammation

2013 ◽  
Vol 27 (12) ◽  
pp. 2041-2054 ◽  
Author(s):  
Xilong Li ◽  
Michael J. Large ◽  
Chad J. Creighton ◽  
Rainer B. Lanz ◽  
Jae-Wook Jeong ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cell Biology ◽  
Embryo Implantation ◽  
Orphan Nuclear Receptor ◽  
Loss Of Function ◽  
Mouse Uterus ◽  
Endometrial Stromal Cells ◽  
Endometrial Stroma ◽  
Stroma Cell

Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII; NR2F2) is an orphan nuclear receptor involved in cell-fate specification, organogenesis, angiogenesis, and metabolism. Ablation of COUP-TFII in the mouse uterus causes infertility due to defects in embryo attachment and impaired uterine stromal cell decidualization. Although the function of COUP-TFII in uterine decidualization has been described in mice, its role in the human uterus remains unknown. We observed that, as in mice, COUP-TFII is robustly expressed in the endometrial stroma of healthy women, and its expression is reduced in the ectopic lesions of women with endometriosis. To interrogate the role of COUP-TFII in human endometrial function, we used a small interfering RNA-mediated loss of function approach in primary human endometrial stromal cells. Attenuation of COUP-TFII expression did not completely block decidualization; rather it had a selective effect on gene expression. To better elucidate the role of COUP-TFII in endometrial stroma cell biology, the COUP-TFII transcriptome was defined by pairing microarray comparison with chromatin immunoprecipitation followed by deep sequencing. Gene ontology analysis demonstrates that COUP-TFII regulates a subset of genes in endometrial stroma cell decidualization such as those involved in cell adhesion, angiogenesis, and inflammation. Importantly this analysis shows that COUP-TFII plays a role in controlling the expression of inflammatory cytokines. The determination that COUP-TFII plays a role in inflammation may add insight into the role of COUP-TFII in embryo implantation and in endometrial diseases such as endometriosis.

scholarly journals The Constitutive Centromere Component CENP-50 Is Required for Recovery from Spindle Damage

2005 ◽  
Vol 25 (23) ◽  
pp. 10315-10328 ◽  
Author(s):  
Yukinori Minoshima ◽  
Tetsuya Hori ◽  
Masahiro Okada ◽  
Hiroshi Kimura ◽  
Tokuko Haraguchi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Mitotic Checkpoint ◽  
Loss Of Function ◽  
Wild Type ◽  
Centromere Function ◽  
Dt40 Cells ◽  
Precise Role ◽  
Chicken Dt40 Cell

ABSTRACT We identified CENP-50 as a novel kinetochore component. We found that CENP-50 is a constitutive component of the centromere that colocalizes with CENP-A and CENP-H throughout the cell cycle in vertebrate cells. To determine the precise role of CENP-50, we examined its role in centromere function by generating a loss-of-function mutant in the chicken DT40 cell line. The CENP-50 knockout was not lethal; however, the growth rate of cells with this mutation was slower than that of wild-type cells. We observed that the time for CENP-50-deficient cells to complete mitosis was longer than that for wild-type cells. Centromeric localization of CENP-50 was abolished in both CENP-H- and CENP-I-deficient cells. Coimmunoprecipitation experiments revealed that CENP-50 interacted with the CENP-H/CENP-I complex in chicken DT40 cells. We also observed severe mitotic defects in CENP-50-deficient cells with apparent premature sister chromatid separation when the mitotic checkpoint was activated, indicating that CENP-50 is required for recovery from spindle damage.

scholarly journals Thioester-Containing Protein-4 Regulates the Drosophila Immune Signaling and Function against the Pathogen Photorhabdus

2016 ◽  
Vol 9 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Upasana Shokal ◽  
Ioannis Eleftherianos
Keyword(s):  
Immune Response ◽  
Photorhabdus Luminescens ◽  
Human Pathogen ◽  
Loss Of Function ◽  
Phenoloxidase Activity ◽  
Microbial Infections ◽  
Immune Pathways ◽  
And Function ◽  
Important Progress

Despite important progress in identifying the molecules that participate in the immune response of Drosophila melanogaster to microbial infections, the involvement of thioester-containing proteins (TEPs) in the antibacterial immunity of the fly is not fully clarified. Previous studies mostly focused on identifying the function of TEP2, TEP3 and TEP6 molecules in the D. melanogaster immune system. Here, we investigated the role of TEP4 in the regulation and function of D. melanogaster host defense against 2 virulent pathogens from the genus Photorhabdus, i.e. the insect pathogenic bacterium Photorhabdus luminescens and the emerging human pathogen P. asymbiotica. We demonstrate that Tep4 is strongly upregulated in adult flies following the injection of Photorhabdus bacteria. We also show that Tep4 loss-of-function mutants are resistant to P. luminescens but not to P. asymbiotica infection. In addition, we find that inactivation of Tep4 results in the upregulation of the Toll and Imd immune pathways, and the downregulation of the Jak/Stat and Jnk pathways upon Photorhabdus infection. We document that loss of Tep4 promotes melanization and phenoloxidase activity in the mutant flies infected with Photorhabdus. Together, these findings generate novel insights into the immune role of TEP4 as a regulator and effector of the D. melanogaster antibacterial immune response.

Abstract TMP25: Long Non-Coding RNA Mediates Stroke-Induced Neurogenesis

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Baoyan Fan ◽  
Wanlong Pan ◽  
Xinli Wang ◽  
Michael Chopp ◽  
Zheng Gang Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Regulation Of Gene Expression ◽  
Artery Occlusion ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Guide Rna ◽  
Non Coding Rna ◽  
Cerebral Artery Occlusion ◽  
Long Non Coding Rna

Background and Purpose: Adult neurogenesis contributes to functional recovery after stroke. Long non-coding RNAs (lncRNAs) regulate stem cell self-renewal and differentiation. However, the role of lncRNAs in stroke-induced neurogenesis remains unknown. Methods and Results: Using lncRNA array and in situ hybridization, we analyzed lncRNA profiles of adult neural stem cells (NSCs) isolated from the subventricular zone neurogenic region in rats subjected to middle cerebral artery occlusion. We found that H19 was the most highly upregulated lncRNA (19 fold) in ischemic NSCs compared with non-ischemic NSCs. Reduction of endogenous H19 in NSCs by CRISPR-Cas9 genome editing significantly decreased the proliferation and increased the apoptosis of ischemic NSCs, as assayed by the number of BrdU + cells (56±5% vs 22±3%, p<0.01, n=3) and Caspase-3/7 activity compared to NSCs transfected with scrambled small guide RNA (sgRNA). Knockdown of H19 significantly decreased the number of Tuj1 + neuroblasts (8±2% vs 5±0.4%, p<0.01, n=3) and NG 2 + oliogodendrocyte progenitor cells (10±1% vs 5±0.3%, p<0.01, n=3), suggesting that deletion of H19 suppresses the proliferation and survival and blocks the differentiation of NSCs into neurons and oligodendrocytes. Additional RNA-sequencing and bioinformatics analyses revealed that genes deregulated by H19 knockdown were involved in transcription, apoptosis, proliferation, cell cycle and response to hypoxia. Western blot analysis validated that loss-of-function and gain-of-function of H19 significantly increased and reduced, respectively, the transcription of cell cycle-related genes including p27. Using ChIRP assay, we found that upregulated H19 in NSCs was physically associated with EZH2 which catalyzes the repressive H3K27me3 histone marker. Knockdown of H19 significantly reduced the enrichment of H3K27me3 at the promoter of p27, leading to the upregulation of p27 expression and consequently inhibition of NSC proliferation. Conclusions: H19 mediates stroke-induced neurogenesis by regulating genes involved in cell cycle and survival through the interaction with chromatin remodeling proteins. Our data provide novel insights into epigenetic regulation of gene expression by lncRNA in neurogenesis.

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