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

Author(s):  
Dominik Lotz ◽  
Jafargholi Imani ◽  
Katrin Ehlers ◽  
Annette Becker

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.

2017 ◽  
Vol 12 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Francesca Laudani ◽  
Cinzia P. Strano ◽  
Martin G. Edwards ◽  
Antonino Malacrinò ◽  
Orlando Campolo ◽  
...  

AbstractRNA interference (RNAi) is a powerful strategy for gene function analysis, and it is also widely studied in view of a promising use in pest control. The red palm weevil, Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae), is one of the most devastating pests of palm in the world. Conventional pest management practices are not adequate to control this insect, thus the development of efficient approaches with minimal environmental impact are needed. In this work, the potential of RNAi in R. ferrugineus has been investigated through the silencing of three different genes (α-amylase, V-ATPase, Ecdysone receptor). For each gene we tested two different doses (1,500 and 5,500 ng) and two delivery techniques (injection and ingestion), evaluating both gene knockdown and mortality on insects. Results show that RNAi mediated gene silencing in R. ferrugineus varies from gene to gene, and that the response is dose-dependent, with stronger effects when dsRNA was administered by injection. In parallel, the same study was carried out with the model organism Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), with results showing a different pattern of response, although the two insects belong to the same order.


Author(s):  
L. Matchett-Oates ◽  
Ehab Mohamaden ◽  
G. C. Spangenberg ◽  
N. O. I. Cogan

AbstractTransient expression systems in mesophyll protoplasts have been utilised in many plant species as an indispensable tool for gene function analysis and efficacious genome editing constructs. However, such a system has not been developed in Cannabis due to the recalcitrant nature of the plant to tissue culture as well as its illegal status for many years. In this study, young expanding leaves from aseptic in vitro Cannabis explants were used for protoplast isolation. Factorial designs were used to optimise variables in viable protoplast isolation and transient expression of GFP, with a range analyses performed to determine, and quantify, significantly impacting variables. Viable protoplast yields as high as 5.7 × 106 were achieved with 2.5% (w/v) Cellulase R-10, 0.3% (w/v) Macerozyme R-10 and 0.7 M mannitol, incubated for 16 h. As indicated by the transient expression of GFP, efficiency reached 23.2% with 30 μg plasmid, 50% PEG, 1 × 106 protoplasts and a transfection duration of 20 min. Application of the optimised protocol for protoplast isolation was successfully evaluated on three subsequent unrelated genotypes to highlight the robustness and broad applicability of the developed technique.


2019 ◽  
Author(s):  
Bethany A. Stahl ◽  
Robert Peuß ◽  
Brittnee McDole ◽  
Alexander Kenzior ◽  
James B. Jaggard ◽  
...  

AbstractAstyanax mexicanus is a well-established and widely used fish model system for evolutionary and developmental biology research. These fish exist as surface forms that inhabit rivers and 30 different populations of cavefish. The establishment of A. mexicanus as an emergent model organism for understanding the evolutionary basis of development and behavior has been accelerated by an increasing availability of genomic approaches to identify genotype-phenotype associations. Despite important progress in the deployment of new technologies, deep mechanistic insights into A. mexicanus evolution and development have been limited by a lack of transgenic lines commonly used in genetic model systems. Here, we expand the toolkit of transgenesis by characterizing two novel stable transgenic lines that were generated using the highly efficient Tol2 system, commonly used to generate transgenic zebrafish. A stable transgenic line consisting of the zebrafish ubiquitin promoter fused to eGFP expressed eGFP ubiquitously throughout development in a surface population of Astyanax. To define specific cell-types, we injected fish with a Cntnap2-mCherry construct that labels lateral line mechanosensory neurons in zebrafish. Strikingly, both constructs appear to label the predicted cell types, suggesting many genetic tools and defined promoter regions in zebrafish are directly transferrable to cavefish. The lines provide proof-of-principle for the application of Tol2 transgenic technology in A. mexicanus. Expansion on these initial transgenic lines will provide a platform to address broadly important problems in the quest to bridge the genotype to phenotype gap.


2021 ◽  
Vol 22 (2) ◽  
pp. 215-236
Author(s):  
Nadine Saul ◽  
Steffen Möller ◽  
Francesca Cirulli ◽  
Alessandra Berry ◽  
Walter Luyten ◽  
...  

AbstractSeveral biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of these has yet collected experimental results of compound-related health changes. Since quality of life is often regarded as more valuable than length of life, we aim to fill this gap with the “Healthy Worm Database” (http://healthy-worm-database.eu). Literature describing health-related compound studies in the aging model Caenorhabditis elegans was screened, and data for 440 compounds collected. The database considers 189 publications describing 89 different phenotypes measured in 2995 different conditions. Besides enabling a targeted search for promising compounds for further investigations, this database also offers insights into the research field of studies on healthy aging based on a frequently used model organism. Some weaknesses of C. elegans-based aging studies, like underrepresented phenotypes, especially concerning cognitive functions, as well as the convenience-based use of young worms as the starting point for compound treatment or phenotype measurement are discussed. In conclusion, the database provides an anchor for the search for compounds affecting health, with a link to public databases, and it further highlights some potential shortcomings in current aging research.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gregory R. Keele ◽  
Jeremy W. Prokop ◽  
Hong He ◽  
Katie Holl ◽  
John Littrell ◽  
...  

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.


Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Decai Tuo ◽  
Peng Zhou ◽  
Pu Yan ◽  
Hongguang Cui ◽  
Yang Liu ◽  
...  

Abstract Background Cassava is an important crop for food security and industry in the least-developed and developing countries. The completion of the cassava genome sequence and identification of large numbers of candidate genes by next-generation sequencing provide extensive resources for cassava molecular breeding and increase the need for rapid and efficient gene function analysis systems in cassava. Several plant virus-induced gene silencing (VIGS) systems have been developed as reverse genetic tools for rapid gene function analysis in cassava. However, these VIGS vectors could cause severe viral symptoms or inefficient gene silencing. Results In this study, we constructed agroinfection-compatible infectious cDNA clones of cassava common mosaic virus isolate CM (CsCMV-CM, genus Potexvirus, family Alphaflexiviridae) that causes systemic infection with mild symptoms in cassava. CsCMV-CM was then modified to a viral vector carrying the Nimble cloning frame, which facilitates the rapid and high-throughput cloning of silencing fragments into the viral genome. The CsCMV-based vector successfully silenced phytoene desaturase (PDS) and magnesium chelatase subunit I (ChlI) in different cassava varieties and Nicotiana benthamiana. The silencing of the ChlI gene could persist for more than two months. Conclusions This CsCMV-based VIGS system provides a new tool for rapid and efficient gene function studies in cassava.


2006 ◽  
Vol 33 (4) ◽  
pp. 347 ◽  
Author(s):  
Changchun Wang ◽  
Xinzhong Cai ◽  
Xuemin Wang ◽  
Zhong Zheng

Arabidopsis thaliana (L.) Heynh. is a model plant species in which to study plant gene functions. Recently developed virus-induced gene silencing (VIGS) offers a rapid and high-throughput technique platform for gene function analysis. In this paper we report optimisation of tobacco rattle virus (TRV)-induced gene silencing in Arabidopsis. The parameters potentially affecting the efficiency of VIGS in Arabidopsis were investigated. These included the concentration and pre-incubation of Agrobacterium inocula (agro-inocula), the concentration of acetosyringone included in agro-inocula, the Agrobacterium inoculation (agro-inoculation) method, the ecotypes and the growth stages of Arabidopsis plants for agro-inoculation, and the growth temperature of agro-inoculated plants. The optimised VIGS procedure involves preparing the agro-inocula with OD600 of 2.0, pre-incubating for 2 h in infiltration buffer containing 200 μm acetosyringone, agro-inoculating by vacuum infiltration, and growth of agro-inoculated plants at 22 −24°C. Following this procedure consistent and highly efficient VIGS was achieved for the genes encoding phytoene desaturase (PDS) and actin in Arabidopsis. The silencing phenotype lasts for at least 6 weeks, and is applicable in at least seven ecotypes, including Col-0, Cvi-0, Sd, Nd-1, Ws-0, Bay-0 and Ler. TRV-induced VIGS was expressed not only in leaves, but also in stems, inflorescences and siliques. However, VIGS was not transmissible through seed to the subsequent generation. The optimised procedure of the TRV-induced gene silencing should facilitate high-throughput functional analysis of genes in Arabidopsis.


1999 ◽  
Vol 12 (4) ◽  
pp. 583-611 ◽  
Author(s):  
Maria E. Cardenas ◽  
M. Cristina Cruz ◽  
Maurizio Del Poeta ◽  
Namjin Chung ◽  
John R. Perfect ◽  
...  

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.


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