DPhK-γ, a putative Drosophila kinase with homology to vertebrate phosphorylase kinase γ subunits: molecular characterisation of the gene and phenotypic analysis of loss of function mutants

1994 ◽  
Vol 245 (5) ◽  
pp. 588-597 ◽  
Author(s):  
Sami M. Bahri ◽  
William Chia
Keyword(s):  
Phosphorylase Kinase ◽  
Molecular Characterisation ◽  
Loss Of Function ◽  
Phenotypic Analysis

16. Physiological effects of IDH1 loss-of-function on Chondrocyte Differentiation through Hedgehog Pathway upregulation

2018 ◽  
Author(s):  
Cassie Tyson
Keyword(s):  
Developmental Stages ◽  
Hedgehog Pathway ◽  
Chondrocyte Differentiation ◽  
Loss Of Function ◽  
Wild Type ◽  
Phenotypic Analysis ◽  
Growth Plate Chondrocytes ◽  
Idh Mutations ◽  
Cartilage Tumors ◽  
Deficient Mice

Cartilage tumors are the most common and terminal primary neoplasms in bone. Physiologically, bones formed through endochondral ossification are regulated by the Hedgehog pathway and Parathyroid hormone-like hormone feedback loop. The upregulation of the infamous Hedgehog pathway has been demonstrated in several non-cartilaginous neoplasms. Recently, frequent mutational events of isocitrate dehydrogenase1 (IDH1) were identified in cartilage tumors. In other neoplasms, IDH mutations produces an oncometabolite that can promote HIF1a activation, contributing to tumorigenesis. Currently, the role of IDH1 mutations in cartilage tumors remain unknown. Investigating the physiological aspect of IDH1proves useful in identifying novel therapeutic targets for cartilage tumors. IDH1 deficient and wild-type littermates, were harvested for forelimbs and hindlimbs at various developmental stages for phenotypic analysis via hematoxylin and eosin staining. Histological analysis demonstrated IDH1 homozygous deficient mice at embryonic stages exhibited dwarfism and an elongated layer of hypertrophic chondrocytes. This was verified via immunohistochemistry Type 10 Collagen staining and Quantitative PCR (qPCR) using the chondrocyte terminal differentiation marker Col10a1. Whole skeletons of IDH1 deficient mice were subjected to skeletal double staining which demonstrated delayed mineralization of underdeveloped IDH1 deficient mice contrasted with wild-type littermates. qPCR was performed to examine the status of chondrocyte differentiation through the Hedgehog pathway in cultured primarymouse growth plate chondrocytes. Interestingly, IDH1 deficient non-neoplastic cells revealed significant upregulation of Hedgehog target molecules in IDH1 deficient chondrocytes. As a result, the loss-offunction of IDH1 was identified as a potential impairment of chondrocyte differentiation and a factor towards chondrocyte tumorgenisis.

scholarly journals PHENOTYPIC ANALYSIS OF OsTPKb LOSS OF FUNCTION MUTANT RICE LINES

2015 ◽  
Vol 8 (4) ◽  
pp. 122-127
Author(s):  
Isayenkov S. V. ◽  
Keyword(s):  
Loss Of Function ◽  
Phenotypic Analysis

scholarly journals AHK3-Mediated Cytokinin Signaling Is Required for the Delayed Leaf Senescence Induced by SSPP

2019 ◽  
Vol 20 (8) ◽  
pp. 2043
Author(s):  
Yanan Wang ◽  
Xiyu Zhang ◽  
Yanjiao Cui ◽  
Lei Li ◽  
Dan Wang ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Protein Phosphatase ◽  
Developmental Process ◽  
Loss Of Function ◽  
Cytokinin Signaling ◽  
Phenotypic Analysis ◽  
Exogenous Cytokinin ◽  
Cytokinin Treatment ◽  
Encoding Gene ◽  
Multiple Signaling

Leaf senescence is a highly-programmed developmental process regulated by an array of multiple signaling pathways. Our group previously reported that overexpression of the protein phosphatase-encoding gene SSPP led to delayed leaf senescence and significantly enhanced cytokinin responses. However, it is still unclear how the delayed leaf senescence phenotype is associated with the enhanced cytokinin responses. In this study, we introduced a cytokinin receptor AHK3 knockout into the 35S:SSPP background. The phenotypic analysis of double mutant revealed that AHK3 loss-of-function reversed the delayed leaf senescence induced by SSPP. Moreover, we found the hypersensitivity of 35S:SSPP to exogenous cytokinin treatment disappeared due to the introduction of AHK3 knockout. Collectively, our results demonstrated that AHK3-mediated cytokinin signaling is required for the delayed leaf senescence caused by SSPP overexpression and the detailed mechanism remains to be further elucidated.

scholarly journals Axial skeletal defects caused by mutation in the spondylocostal dysplasia/pudgy geneDll3are associated with disruption of the segmentation clock within the presomitic mesoderm

Development ◽  
2002 ◽  
Vol 129 (7) ◽  
pp. 1795-1806 ◽  
Author(s):  
Sally L. Dunwoodie ◽  
Melanie Clements ◽  
Duncan B. Sparrow ◽  
Xin Sa ◽  
Ronald A. Conlon ◽  
...  
Keyword(s):  
Gene Targeting ◽  
Skeletal Dysplasia ◽  
Null Allele ◽  
Developmental Origins ◽  
Loss Of Function ◽  
Presomitic Mesoderm ◽  
Phenotypic Analysis ◽  
Segmentation Clock ◽  
Skeletal Defects ◽  
Somite Formation

A loss-of-function mutation in the mouse delta-like3 (Dll3) gene has been generated following gene targeting, and results in severe axial skeletal defects. These defects, which consist of highly disorganised vertebrae and costal defects, are similar to those associated with the Dll3-dependent pudgy mutant in mouse and with spondylocostal dysplasia (MIM 277300) in humans. This study demonstrates that Dll3neo and Dll3pu are functionally equivalent alleles with respect to the skeletal dysplasia, and we suggest that the three human DLL3 mutations associated with spondylocostal dysplasia are also functionally equivalent to the Dll3neo null allele. Our phenotypic analysis of Dll3neo/Dll3neo mutants shows that the developmental origins of the skeletal defects lie in delayed and irregular somite formation, which results in the perturbation of anteroposterior somite polarity. As the expression of Lfng, Hes1, Hes5 and Hey1 is disrupted in the presomitic mesoderm, we suggest that the somitic aberrations are founded in the disruption of the segmentation clock that intrinsically oscillates within presomitic mesoderm.

scholarly journals PDK1 has a pleiotropic PINOID-independent role in Arabidopsis development

2019 ◽  
Author(s):  
Yao Xiao ◽  
Remko Offringa
Keyword(s):  
Auxin Transport ◽  
Primary Root ◽  
Loss Of Function ◽  
In Planta ◽  
Phenotypic Analysis ◽  
Master Regulator ◽  
Dna Insertion ◽  
Dependent Protein ◽  
Eukaryotic Organisms ◽  
Auxin Efflux Carriers

AbstractThe 3-Phosphoinositide-Dependent Protein Kinase 1 (PDK1) is a conserved and important master regulator of AGC kinases in eukaryotic organisms. pdk1 loss-of-function causes a lethal phenotype in animals and yeast. In contrast, only very mild phenotypic defects have been reported for the pdk1 loss-of-function mutant of the model plant Arabidopsis thaliana (Arabidopsis). The Arabidopsis genome contains two PDK1 genes, hereafter called PDK1 and PDK2. Here we show that the previously reported Arabidopsis pdk1 T-DNA insertion alleles are not true loss-of-function mutants. By using CRISPR/Cas9 technology, we created true loss-of-function pdk1 alleles, and pdk1 pdk2 double mutants carrying these alleles showed multiple growth and development defect, including fused cotyledons, a short primary root, dwarf stature, late flowering, and reduced seed production caused by defects in male fertility. Surprisingly, pdk1 pdk2 mutants did not phenocopy pid mutants, and together with the observations that PDK1 overexpression does not phenocopy the effect of PID overexpression, and that pdk1 pdk2 loss-of-function does not change PID subcellular localization, we conclude that PDK1 is not essential for PID membrane localization or functionality in planta. Nonetheless, most pdk1 pdk2 phenotypes could be correlated with impaired auxin transport. PDK1 is highly expressed in vascular tissues and YFP:PDK1 is relatively abundant at the basal/rootward side of root stele cells, where it colocalizes with PIN auxin efflux carriers, and the AGC1 kinases PAX and D6PK/D6PKLs. Our genetic and phenotypic analysis suggests that PDK1 is likely to control auxin transport as master regulator of these AGC1 kinases in Arabidopsis.

scholarly journals Genomic and phenotypic analysis of COVID-19-associated pulmonary aspergillosis isolates of Aspergillus fumigatus

2020 ◽  
Author(s):  
Jacob L. Steenwyk ◽  
Matthew E. Mead ◽  
Patrícia Alves de Castro ◽  
Clara Valero ◽  
André Damasio ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Copy Number Variants ◽  
Antifungal Drugs ◽  
Microbial Pathogens ◽  
Nucleotide Polymorphisms ◽  
Loss Of Function ◽  
Phenotypic Analysis ◽  
Pulmonary Aspergillosis ◽  
Global Pandemic ◽  
Reference Strains

AbstractThe ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) first described from Wuhan, China. A subset of COVID-19 patients has been reported to have acquired secondary infections by microbial pathogens, such as fungal opportunistic pathogens from the genus Aspergillus. To gain insight into COVID-19 associated pulmonary aspergillosis (CAPA), we analyzed the genomes and characterized the phenotypic profiles of four CAPA isolates of Aspergillus fumigatus obtained from patients treated in the area of North Rhine-Westphalia, Germany. By examining the mutational spectrum of single nucleotide polymorphisms, insertion-deletion polymorphisms, and copy number variants among 206 genes known to modulate A. fumigatus virulence, we found that CAPA isolate genomes do not exhibit major differences from the genome of the Af293 reference strain. By examining virulence in an invertebrate moth model, growth in the presence of osmotic, cell wall, and oxidative stressors, and the minimum inhibitory concentration of antifungal drugs, we found that CAPA isolates were generally, but not always, similar to A. fumigatus reference strains Af293 and CEA17. Notably, CAPA isolate D had more putative loss of function mutations in genes known to increase virulence when deleted (e.g., in the FLEA gene, which encodes a lectin recognized by macrophages). Moreover, CAPA isolate D was significantly more virulent than the other three CAPA isolates and the A. fumigatus reference strains tested. These findings expand our understanding of the genomic and phenotypic characteristics of isolates that cause CAPA.

scholarly journals Molecular and Phenotypic Analysis of 25 Recessive, Homozygous-Viable Alleles at the Mouse agouti Locus

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 659-674
Author(s):  
Rosalynn J Miltenberger ◽  
Kazumasa Wakamatsu ◽  
Shosuke Ito ◽  
Richard P Woychik ◽  
Liane B Russell ◽  
...  
Keyword(s):  
Loss Of Function ◽  
Wild Type ◽  
Allelic Series ◽  
Phenotypic Analysis ◽  
Protein Coding ◽  
Agouti Locus ◽  
Expression Control ◽  
Gene Expression Control ◽  
Specific Locus

Abstract Agouti is a paracrine-acting, transient antagonist of melanocortin 1 receptors that specifies the subapical band of yellow on otherwise black hairs of the wild-type coat. To better understand both agouti structure/function and the germline damage caused by chemicals and radiation, an allelic series of 25 recessive, homozygous-viable agouti mutations generated in specific-locus tests were characterized. Visual inspection of fur, augmented by quantifiable chemical analysis of hair melanins, suggested four phenotypic categories (mild, moderate, umbrous-like, severe) for the 18 hypomorphs and a single category for the 7 amorphs (null). Molecular analysis indicated protein-coding alterations in 8 hypomorphs and 6 amorphs, with mild-moderate phenotypes correlating with signal peptide or basic domain mutations, and more devastating phenotypes resulting from C-terminal lesions. Ten hypomorphs and one null demonstrated wild-type coding potential, suggesting that they contain mutations elsewhere in the ≥125-kb agouti locus that either reduce the level or alter the temporal/spatial distribution of agouti transcripts. Beyond the notable contributions to the field of mouse germ cell mutagenesis, analysis of this allelic series illustrates that complete abrogation of agouti function in vivo occurs most often through protein-coding lesions, whereas partial loss of function occurs slightly more frequently at the level of gene expression control.

scholarly journals The Drosophila Forkhead/Fox transcription factor Jumeau mediates specific cardiac progenitor cell divisions by regulating expression of the kinesin Nebbish

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew J. Kump ◽  
Manoj Panta ◽  
Kristopher R. Schwab ◽  
Mark H. Inlow ◽  
Shaad M. Ahmad
Keyword(s):  
Cell Division ◽  
Progenitor Cell ◽  
Expression Profiles ◽  
Loss Of Function ◽  
Phenotypic Analysis ◽  
Specific Expression ◽  
Cardiac Progenitor Cell ◽  
Cell Divisions ◽  
Downstream Effectors

AbstractForkhead (Fkh/Fox) domain transcription factors (TFs) mediate multiple cardiogenic processes in both mammals and Drosophila. We showed previously that the Drosophila Fox gene jumeau (jumu) controls three categories of cardiac progenitor cell division—asymmetric, symmetric, and cell division at an earlier stage—by regulating Polo kinase activity, and mediates the latter two categories in concert with the TF Myb. Those observations raised the question of whether other jumu-regulated genes also mediate all three categories of cardiac progenitor cell division or a subset thereof. By comparing microarray-based expression profiles of wild-type and jumu loss-of-function mesodermal cells, we identified nebbish (neb), a kinesin-encoding gene activated by jumu. Phenotypic analysis shows that neb is required for only two categories of jumu-regulated cardiac progenitor cell division: symmetric and cell division at an earlier stage. Synergistic genetic interactions between neb, jumu, Myb, and polo and the rescue of jumu mutations by ectopic cardiac mesoderm-specific expression of neb demonstrate that neb is an integral component of a jumu-regulated subnetwork mediating cardiac progenitor cell divisions. Our results emphasize the central role of Fox TFs in cardiogenesis and illustrate how a single TF can utilize different combinations of other regulators and downstream effectors to control distinct developmental processes.

scholarly journals Double Mutant Analysis with the Large Flower Mutant, ohbana1, to Explore the Regulatory Network Controlling the Flower and Seed Sizes in Arabidopsis thaliana

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1881
Author(s):  
Vuong Quoc Nhat ◽  
Yusuke Kazama ◽  
Kotaro Ishii ◽  
Sumie Ohbu ◽  
Hisato Kunitake ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Regulatory Network ◽  
Double Mutant ◽  
Nuclear Dna ◽  
Loss Of Function ◽  
Phenotypic Analysis ◽  
Regulatory Pathways ◽  
Floral Organs ◽  
Size Regulation ◽  
Large Flower

Two growth processes, cell proliferation and expansion, determine plant species-specific organ sizes. A large flower mutant in Arabidopsis thaliana, ohbana1 (ohb1), was isolated from a mutant library. In the ohb1 flowers, post-mitotic cell expansion and endoreduplication of nuclear DNA were promoted. The whole-genome resequencing and genetic analysis results showed that the loss of function in MEDIATOR16 (MED16), a mediator complex subunit, was responsible for the large flower phenotypes exhibited by ohb1. A phenotypic analysis of the mutant alleles in MED16 and the double mutants created by crossing ohb1 with representative large flower mutants revealed that MED16 and MED25 share part of the negative petal size regulatory pathways. Furthermore, the double mutant analyses suggested that there were genetically independent pathways leading to cell size restrictions in the floral organs which were not related to the MED complex. Several double mutants also formed larger and heavier seeds than the wild type and single mutant plants, which indicated that MED16 was involved in seed size regulation. This study has revealed part of the size-regulatory network in flowers and seeds through analysis of the ohb1 mutant, and that the size-regulation pathways are partially different between floral organs and seeds.

scholarly journals An uncanonical transcription factor-DREB2B regulates seed vigor negatively through ABA pathway

2020 ◽  
Author(s):  
Faiza Ali ◽  
Zhenzhen Wei ◽  
Yonghui Li ◽  
Lei Gan ◽  
Zuoren Yang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Seed Vigor ◽  
Negative Regulator ◽  
Loss Of Function ◽  
Phenotypic Analysis ◽  
Molecular Approaches ◽  
Element Binding Protein ◽  
Transgenic Lines ◽  
Important Trait ◽  
Responsive Element

AbstractSeed vigor is an important trait for ecology, agronomy, and economy and varies with different plant species and environmental conditions. Dehydration-Responsive Element-Binding Protein 2B (DREB2B), a subgroup of the DREB transcription factor family, is well-known in drought resistance. However, the role of DREB2B in the regulation of seed vigor has not been identified. Here, we found that DREB2B is a negative regulator of seed vigor by ABA-mediated pathway in Arabidopsis with loss of function mutant and over-expressed transgenic lines. Furthermore, DREB2B showed epistatic and parallel to ABI3 simultaneously in seed vigor regulation by genetic and molecular approaches. DREB2B homolog gene (GhDREB2B-A09) was also identified in cotton. The expression analysis indicated that transcripts of DREB2B were higher in mature dry seed, and the transgenic plants showed the conservative roles of DREB2B in Arabidopsis and cotton. In addition, we identified that DREB2B interacted with RADICAL-INDUCED CELL DEATH1 (RCD1) to involve seed vigor regulation together in Arabidopsis and cotton with BiFC experiment and mutant phenotypic analysis. Collectively it is concluded that DREB2B interacting with RCD1 or SRO1 function at upstream of and synergistic with ABI3 to regulate seed vigor negatively in Arabidopsis and cotton, which provides novel knowledge in the seed development study.HighlightsDREB2B transcription is seed specific and a negative regulator of seed vigor by ABA-mediated pathway, which interacts with RCD1s, and functions synergistically with ABI3 to affecet seed germination and vigor in Arabidopsis and cotton.

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