The Aryl Hydrocarbon ReceptorsansXenobiotics: Endogenous Function in Genetic Model Systems

2007 ◽  
Vol 72 (3) ◽  
pp. 487-498 ◽  
Author(s):  
Brian J. McMillan ◽  
Christopher A. Bradfield
Keyword(s):  
Genetic Model ◽  
Model Systems ◽  
Aryl Hydrocarbon

scholarly journals Sept8/SEPTIN8 involvement in cellular structure and kidney damage is identified by genetic mapping and a novel human tubule hypoxic model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gregory R. Keele ◽  
Jeremy W. Prokop ◽  
Hong He ◽  
Katie Holl ◽  
John Littrell ◽  
...  
Keyword(s):  
Complex Traits ◽  
Genetic Model ◽  
Association Studies ◽  
Model Systems ◽  
Linear Mixed Effect Model ◽  
Genome Wide Association Studies ◽  
Tubulointerstitial Injury ◽  
Heritable Variation ◽  
Mixed Effect

AbstractChronic kidney disease (CKD), which can ultimately progress to kidney failure, is influenced by genetics and the environment. Genes identified in human genome wide association studies (GWAS) explain only a small proportion of the heritable variation and lack functional validation, indicating the need for additional model systems. Outbred heterogeneous stock (HS) rats have been used for genetic fine-mapping of complex traits, but have not previously been used for CKD traits. We performed GWAS for urinary protein excretion (UPE) and CKD related serum biochemistries in 245 male HS rats. Quantitative trait loci (QTL) were identified using a linear mixed effect model that tested for association with imputed genotypes. Candidate genes were identified using bioinformatics tools and targeted RNAseq followed by testing in a novel in vitro model of human tubule, hypoxia-induced damage. We identified two QTL for UPE and five for serum biochemistries. Protein modeling identified a missense variant within Septin 8 (Sept8) as a candidate for UPE. Sept8/SEPTIN8 expression increased in HS rats with elevated UPE and tubulointerstitial injury and in the in vitro hypoxia model. SEPTIN8 is detected within proximal tubule cells in human kidney samples and localizes with acetyl-alpha tubulin in the culture system. After hypoxia, SEPTIN8 staining becomes diffuse and appears to relocalize with actin. These data suggest a role of SEPTIN8 in cellular organization and structure in response to environmental stress. This study demonstrates that integration of a rat genetic model with an environmentally induced tubule damage system identifies Sept8/SEPTIN8 and informs novel aspects of the complex gene by environmental interactions contributing to CKD risk.

scholarly journals Antifungal Activities of Antineoplastic Agents:Saccharomyces cerevisiae as a Model System To Study Drug Action

1999 ◽  
Vol 12 (4) ◽  
pp. 583-611 ◽  
Author(s):  
Maria E. Cardenas ◽  
M. Cristina Cruz ◽  
Maurizio Del Poeta ◽  
Namjin Chung ◽  
John R. Perfect ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Kinase Inhibitor ◽  
Genetic Model ◽  
Fungal Infections ◽  
Study Drug ◽  
Drug Action ◽  
Mechanisms Of Action ◽  
Model Systems ◽  
Screening Tools ◽  
Sphingolipid Metabolism

SUMMARY Recent evolutionary studies reveal that microorganisms including yeasts and fungi are more closely related to mammals than was previously appreciated. Possibly as a consequence, many natural-product toxins that have antimicrobial activity are also toxic to mammalian cells. While this makes it difficult to discover antifungal agents without toxic side effects, it also has enabled detailed studies of drug action in simple genetic model systems. We review here studies on the antifungal actions of antineoplasmic agents. Topics covered include the mechanisms of action of inhibitors of topoisomerases I and II; the immunosuppressants rapamycin, cyclosporin A, and FK506; the phosphatidylinositol 3-kinase inhibitor wortmannin; the angiogenesis inhibitors fumagillin and ovalicin; the HSP90 inhibitor geldanamycin; and agents that inhibit sphingolipid metabolism. In general, these natural products inhibit target proteins conserved from microorganisms to humans. These studies highlight the potential of microorganisms as screening tools to elucidate the mechanisms of action of novel pharmacological agents with unique effects against specific mammalian cell types, including neoplastic cells. In addition, this analysis suggests that antineoplastic agents and derivatives might find novel indications in the treatment of fungal infections, for which few agents are presently available, toxicity remains a serious concern, and drug resistance is emerging.

scholarly journals A circadian clock in Saccharomyces cerevisiae

2010 ◽  
Vol 107 (5) ◽  
pp. 2043-2047 ◽  
Author(s):  
Zheng Eelderink-Chen ◽  
Gabriella Mazzotta ◽  
Marcel Sturre ◽  
Jasper Bosman ◽  
Till Roenneberg ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Model ◽  
Circadian Clocks ◽  
Model Systems ◽  
Model Organisms ◽  
Biological Clocks ◽  
Experimental Systems ◽  
Fundamental Biological Process ◽  
Free Running ◽  
And Behavior

Circadian timing is a fundamental biological process, underlying cellular physiology in animals, plants, fungi, and cyanobacteria. Circadian clocks organize gene expression, metabolism, and behavior such that they occur at specific times of day. The biological clocks that orchestrate these daily changes confer a survival advantage and dominate daily behavior, for example, waking us in the morning and helping us to sleep at night. The molecular mechanism of circadian clocks has been sketched out in genetic model systems from prokaryotes to humans, revealing a combination of transcriptional and posttranscriptional pathways, but the clock mechanism is far from solved. Although Saccharomyces cerevisiae is among the most powerful genetic experimental systems and, as such, could greatly contribute to our understanding of cellular timing, it still remains absent from the repertoire of circadian model organisms. Here, we use continuous cultures of yeast, establishing conditions that reveal characteristic clock properties similar to those described in other species. Our results show that metabolism in yeast shows systematic circadian entrainment, responding to cycle length and zeitgeber (stimulus) strength, and a (heavily damped) free running rhythm. Furthermore, the clock is obvious in a standard, haploid, auxotrophic strain, opening the door for rapid progress into cellular clock mechanisms.

Minor millets as model system to study C4 photosynthesis -A review

2015 ◽  
Vol 36 (4) ◽  
Author(s):  
P. Vivitha ◽  
D. Vijayalakshmi
Keyword(s):  
Distribution System ◽  
Genetic Model ◽  
Crop Improvement ◽  
Model System ◽  
Life Cycles ◽  
Model Systems ◽  
Subtype C ◽  
Model Species ◽  
Kranz Anatomy ◽  
Minor Millets

C<sub>4</sub> photosynthesis is the primary mode of carbon capture and drives productivity in several major food crops and bioenergy grasses. Gains in productivity associated with C<sub>4</sub> photosynthesis include improved water and nitrogen use efficiencies. Within grasses rice and brachypodium are used as model species. Since these two crops are using C<sub>3</sub> photosynthesis for their growth and development, it cannot be used as model for to study C<sub>4</sub> photosynthesis. In order to characterize the evolutionary innovations and to provide genomic insight into crop improvement for the many important crop species, a new genomic and genetic model species is required. Minor millets have small diploid genomes, shorter life cycles, self pollination and prolific seed production. Due to these characteristics it gains importance over major C<sub>4</sub> species which lack all of these traits. Within Minor millets, <italic>Setaria italica</italic> and <italic>Setaria viridis</italic> are used as model systems since these crops fulfils all the traits responsible to be a model species. Importantly, <italic>Setaria</italic> species uses NADP-Malic enzyme subtype C<sub>4</sub> photosynthetic system to fix carbon and therefore is a potential powerful model system for dissecting C<sub>4</sub> photosynthesis. C<sub>4</sub> grasses have a shorter distance between longitudinal veins in the leaves than C<sub>3</sub> grasses. The C<sub>4</sub> grasses have denser transverse and small longitudinal veins than the C<sub>3</sub> grasses. It indicates that C<sub>4</sub> grasses have a structurally superior photosynthate translocation and water distribution system by developing denser networks of small longitudinal and transverse veins. <italic>Setaria</italic> has high vein density and kranz anatomy that helps to concentrate CO<sub>2</sub> in the bundle sheath cells. This minimizes photorespiration thereby prevents the loss of energy.

scholarly journals Fbxw7 is a driver of uterine carcinosarcoma by promoting epithelial-mesenchymal transition

2019 ◽  
Vol 116 (51) ◽  
pp. 25880-25890 ◽  
Author(s):  
Ileana C. Cuevas ◽  
Subhransu S. Sahoo ◽  
Ashwani Kumar ◽  
He Zhang ◽  
Jill Westcott ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Genetic Model ◽  
Precancerous Lesions ◽  
Lineage Tracing ◽  
Model Systems ◽  
Cancer Type ◽  
Cell Of Origin ◽  
Uterine Carcinosarcoma ◽  
Mesenchymal Transition

Uterine carcinosarcoma is an aggressive variant of endometrial carcinoma characterized by unusual histologic features including discrete malignant epithelial and mesenchymal components (carcinoma and sarcoma). Recent studies have confirmed a monoclonal origin, and comprehensive genomic characterizations have identified mutations such asTp53andPten. However, the biological origins and specific combination of driver events underpinning uterine carcinosarcoma have remained mysterious. Here, we explored the role of the tumor suppressorFbxw7in endometrial cancer through defined genetic model systems. Inactivation ofFbxw7andPtenresulted in the formation of precancerous lesions (endometrioid intraepithelial neoplasia) and well-differentiated endometrioid adenocarcinomas. Surprisingly, all adenocarcinomas eventually developed into definitive uterine carcinosarcomas with carcinomatous and sarcomatous elements including heterologous differentiation, yielding a faithful genetically engineered model of this cancer type. Genomic analysis showed that most tumors spontaneously acquiredTrp53mutations, pointing to a triad of pathways (p53, PI3K, and Fbxw7) as the critical combination underpinning uterine carcinosarcoma, and to Fbxw7 as a key driver of this enigmatic endometrial cancer type. Lineage tracing provided formal genetic proof that the uterine carcinosarcoma cell of origin is an endometrial epithelial cell that subsequently undergoes a prominent epithelial–mesenchymal transition underlying the attainment of a highly invasive phenotype specifically driven by Fbxw7.

scholarly journals Identification and functional characterization of muscle satellite cells in Drosophila

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Dhananjay Chaturvedi ◽  
Heinrich Reichert ◽  
Rajesh D Gunage ◽  
K VijayRaghavan
Keyword(s):  
Stem Cells ◽  
Muscle Fiber ◽  
Satellite Cells ◽  
Genetic Model ◽  
Functional Characterization ◽  
Model Systems ◽  
Muscle Stem Cells ◽  
Muscle Satellite Cells ◽  
Adult Muscle ◽  
Functional Features

Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mechanisms of myogenesis are remarkably similar in vertebrates and invertebrates. Strikingly, however, satellite cells, the adult muscle stem cells that are essential for the regeneration of damaged muscles in vertebrates, have not been reported in invertebrates. In this study, we show that lineal descendants of muscle stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surface and in close proximity to the mature muscle fibers. Normally quiescent, following muscle fiber injury, we show that these cells express Zfh1 and engage in Notch-Delta-dependent proliferative activity and generate lineal descendant populations, which fuse with the injured muscle fiber. In view of strikingly similar morphological and functional features, we consider these novel cells to be the Drosophila equivalent of vertebrate muscle satellite cells.

scholarly journals Towards A Genetic Model Organism: An Efficient Method For Stable Genetic Transformation of Eschscholzia Californica (Ranunculales)

2021 ◽  
Author(s):  
Dominik Lotz ◽  
Jafargholi Imani ◽  
Katrin Ehlers ◽  
Annette Becker
Keyword(s):  
Genetic Transformation ◽  
Genetic Model ◽  
Function Analysis ◽  
Model Organism ◽  
Protoplast Isolation ◽  
Model Systems ◽  
Eschscholzia Californica ◽  
Genetic Manipulations ◽  
California Poppy ◽  
Gene Function Analysis

Abstract California poppy (Eschscholzia californica) is a member of the Ranunculales, the sister order to all other eudicots and as such in a phylogenetically highly informative position. Ranunculales are known for their diverse floral morphologies and biosynthesis of many pharmaceutically relevant alkaloids. E. californica it is widely used as model system to study the conservation of flower developmental control genes. However, within the Ranunculales, options for stable genetic manipulations are rare and genetic model systems are thus difficult to establish. Here, we present a method for the efficient and stable genetic transformation via Agrobacterium tumefaciens-mediated transformation, somatic embryo induction, and regeneration of E. californica. Further, we provide a rapid method for protoplast isolation and transformation. This allows the study of gene functions in a single-cell and full plant context to enable gene function analysis and modification of alkaloid biosynthesis pathways by e.g. genome editing techniques providing important genetic resources for the genetic model organism E. californica.

scholarly journals The Cell Biology of LRRK2 in Parkinson’s Disease

2021 ◽  
Author(s):  
Ahsan Usmani ◽  
Farbod Shavarebi ◽  
Annie Hiniker
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Biology ◽  
Kinase Inhibitor ◽  
Genetic Model ◽  
Point Mutations ◽  
Model Systems ◽  
Rab Gtpases ◽  
Recent Developments ◽  
Lrrk2 Kinase

Point mutations in Leucine-rich repeat kinase 2 (LRRK2) are the most common cause of familial Parkinson’s disease (PD) and are implicated in a significant portion of apparently sporadic PD. Clinically, LRRK2-driven PD is indistinguishable from sporadic PD, making it an attractive genetic model for the much more common sporadic PD. In this review, we highlight recent advances in understanding LRRK2's subcellular functions using LRRK2-PD models, while also considering some of the limitations of these model systems. Recent developments of particular importance include new evidence of key LRRK2 functions in the endolysosomal system and LRRK2’s regulation of and by Rab GTPases. Additionally, LRRK2's interaction with the cytoskeleton allowed elucidation of the LRRK2 structure and appears relevant to LRRK2 protein degradation and LRRK2 kinase inhibitor therapies. We further discuss how LRRK2's interactions with other PD-driving genes, such as VPS35, GCase, and α-synuclein, may highlight cellular pathways more broadly disrupted in PD.

Multimodal integration across spatiotemporal scales to guide invertebrate locomotion

2021 ◽  
Author(s):  
Jean-Michel Mongeau ◽  
Lorian E Schweikert ◽  
Alexander L Davis ◽  
Michael S Reichert ◽  
Jessleen K Kanwal
Keyword(s):  
Genetic Model ◽  
Spatial Scales ◽  
Fruit Fly ◽  
Model Systems ◽  
Ecological Niches ◽  
Multimodal Integration ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Challenges And Opportunities ◽  
Spatiotemporal Scales

SYNOPSIS Locomotion is a hallmark of organisms that has enabled adaptive radiation to an extraordinarily diverse class of ecological niches, and allows animals to move across vast distances. Sampling from multiple sensory modalities enables animals to acquire rich information to guide locomotion. Locomotion without sensory feedback is haphazard, therefore sensory and motor systems have evolved complex interactions to generate adaptive behavior. Notably, sensory-guided locomotion acts over broad spatial and temporal scales to permit goal-seeking behavior, whether to localize food by tracking an attractive odor plume or to search for a potential mate. How does the brain integrate multimodal stimuli over different temporal and spatial scales to effectively control behavior? In this review, we classify locomotion into three ordinally ranked hierarchical layers that act over distinct spatiotemporal scales: stabilization, motor primitives, and higher-order tasks, respectively. We discuss how these layers present unique challenges and opportunities for sensorimotor integration. We focus on recent advances in invertebrate locomotion due to their accessible neural and mechanical signals from the whole brain, limbs and sensors. Throughout, we emphasize neural-level description of computations for multimodal integration in genetic model systems, including the fruit fly, Drosophila melanogaster, and the yellow fever mosquito, Aedes aegypti. We identify that summation (e.g. gating) and weighting—which are inherent computations of spiking neurons—underlie multimodal integration across spatial and temporal scales, therefore suggesting collective strategies to guide locomotion.

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